Activation of Ice Protection, 38328-38340 [E9-18483]
Download as PDF
<![CDATA[
38328
§ 26.41
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
Audits and corrective action.
*
*
*
*
*
(d) * * *
(1) The contracts of licensees and
other entities with C/Vs and HHScertified laboratories must reserve the
right to audit the C/V, the C/V’s
subcontractors providing FFD program
services, and the HHS-certified
laboratories at any time, including at
unannounced times, as well as to review
all information and documentation that
is reasonably relevant to the audits.
*
*
*
*
*
■ 4. In § 26.69, paragraphs (c)(3) and
(d)(2) are revised to read as follows:
§ 26.69 Authorization with potentially
disqualifying fitness-for-duty information.
*
*
*
*
*
(c) * * *
(3) If the designated reviewing official
determines that a determination of
fitness is required, verify that a
professional with the appropriate
qualifications, as specified in
§ 26.189(a), has indicated that the
individual is fit to safely and
competently perform his or her duties;
*
*
*
*
*
(d) * * *
(2) If the designated reviewing official
concludes that a determination of
fitness is required, verify that a
professional with the appropriate
qualifications, as specified in
§ 26.189(a), has indicated that the
individual is fit to safely and
competently perform his or her duties;
and
*
*
*
*
*
■ 5. In § 26.137, paragraphs (d)(2)(i),
(d)(5), and (e)(6)(v) are revised to read
as follows:
§ 26.137
control.
Quality assurance and quality
sroberts on DSKD5P82C1PROD with RULES
*
*
*
*
*
(d) * * *
(2) * * *
(i) Colorimetric pH tests must have a
dynamic range of 2 to 12 and pH meters
must be capable of measuring pH to one
decimal place.
*
*
*
*
*
(5) Each analytical run performed to
conduct initial validity testing shall
include at least one quality control
sample that appears to be a donor
specimen to the licensee testing facility
technicians.
*
*
*
*
*
(e) * * *
(6) * * *
(v) At least one positive control,
certified to be positive by an HHScertified laboratory, which appears to be
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
a donor specimen to the licensee testing
facility technicians.
*
*
*
*
*
■ 6. In § 26.153, paragraph (f)(3) is
revised to read as follows:
§ 26.153 Using certified laboratories for
testing urine specimens.
*
*
*
*
*
(f) * * *
(3) The laboratory shall maintain test
records in confidence, consistent with
the requirements of § 26.37, and use
them with the highest regard for
individual privacy.
*
*
*
*
*
Dated at Rockville, Maryland, this 27th day
of July 2009.
For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. E9–18364 Filed 7–31–09; 8:45 am]
BILLING CODE 7590–01–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No.: FAA–2007–27654; Amendment
No. 25–129]
RIN 2120–AI90
Activation of Ice Protection
AGENCY: Federal Aviation
Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The Federal Aviation
Administration amends the
airworthiness standards applicable to
transport category airplanes certificated
for flight in icing conditions. The rule
requires a means to ensure timely
activation of the airframe ice protection
system. This rule is the result of
information gathered from a review of
icing accidents and incidents, and will
improve the level of safety for new
airplane designs for operations in icing
conditions.
DATES: This amendment becomes
effective September 2, 2009.
FOR FURTHER INFORMATION CONTACT: For
technical questions concerning this final
rule contact Kathi Ishimaru, FAA,
Propulsion and Mechanical Systems
Branch, ANM–112, Transport Airplane
Directorate, Aircraft Certification
Service, 1601 Lind Ave., SW., Renton,
Washington 98057–3356; telephone
(425) 227–2674; fax: (425) 227–1320, email: kathi.ishimaru@faa.gov. For legal
questions concerning this final rule
contact Douglas Anderson, FAA, Office
PO 00000
Frm 00006
Fmt 4700
Sfmt 4700
of Regional Counsel, Federal Aviation
Administration, 1601 Lind Ave., SW.,
Renton, Washington 98057–3356;
telephone (425) 227–2166; fax: (425)
227–1007, e-mail:
Douglas.Anderson@faa.gov.
SUPPLEMENTARY INFORMATION:
Authority for This Rulemaking
The FAA’s authority to issue rules on
aviation safety is found in Title 49 of the
United States Code. Subtitle I, Section
106 describes the authority of the FAA
Administrator. Subtitle VII, Aviation
Programs, describes in more detail the
scope of the agency’s authority.
This rulemaking is promulgated
under the authority described in
Subtitle VII, Part A, Subpart III, Section
44701, ‘‘General requirements.’’ Under
that section, the FAA is charged with
promoting safe flight of civil aircraft in
air commerce by prescribing minimum
standards required in the interest of
safety for the design and performance of
aircraft. This regulation is within the
scope of that authority because it
prescribes new safety standards for the
design of transport category airplanes.
I. Background
On October 31, 1994, an accident
involving an Avions de Transport
Regional ATR 72 series airplane
occurred in icing conditions.1 This
prompted the FAA to initiate a review
of aircraft inflight icing safety and
determine changes that could be made
to increase the level of safety. In May
1996, the FAA sponsored the
International Conference on Aircraft
Inflight Icing where icing specialists
recommended improvements to increase
the level of safety of aircraft operating
in icing conditions. The FAA reviewed
the conference recommendations and
developed a comprehensive multi-year
icing plan. The FAA Inflight Aircraft
Icing Plan (Icing Plan), dated April
1997,2 described various activities the
FAA was contemplating to improve
safety when operating in icing
conditions. In accordance with the Icing
Plan, the FAA tasked the Aviation
Rulemaking Advisory Committee
(ARAC),3 through its Ice Protection
Harmonization Working Group, to
consider the need for ice detectors or
other acceptable means to warn
flightcrews of ice accretion on critical
surfaces requiring crew action. This rule
1 This accident and an Empressa Brasilia accident
resulted in NTSB recommendations nos. A–96–56
and A–98–91. This final rule partially addresses
these safety recommendations.
2 FAA Inflight Aircraft Icing Plan, dated April
1997, available in the Docket.
3 Published in the Federal Register, December 8,
1997 (62 FR 64621).
E:\FR\FM\03AUR1.SGM
03AUR1
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
is based on ARAC’s recommendations to
the FAA.
A. Summary of the NPRM
The notice of proposed rulemaking
(NPRM), Notice No. 07–07, published in
the Federal Register on April 26, 2007
(72 FR 20924), is the basis for this
amendment. The comment period
closed July 25, 2007. In the NPRM, we
proposed to revise the airworthiness
standards for type certification of
transport category airplanes to add
requirements to ensure the timely
activation of an airframe ice protection
system (IPS). We also proposed to add
requirements to reduce the flightcrew
workload associated with operation of
an airframe IPS that is manually cycled,
and to ensure the Airplane Flight
Manual includes IPS procedures for
operation.
sroberts on DSKD5P82C1PROD with RULES
B. Summary of the Final Rule
The FAA is adopting this final rule
because accidents and incidents
occurred where the flightcrew did not
operate the airframe IPS in a timely
manner and because of concerns over
the flightcrew workload required to
operate an airframe IPS that the
flightcrew must manually cycle when
they observe ice accretions. The final
rule addresses these concerns by
ensuring that flightcrews are provided
with a clear means to know when to
activate the airframe IPS. The final rule
reduces the workload associated with
monitoring ice accretions by requiring a
system that operates continuously, a
system that automatically cycles the
IPS, or an alert to the flighcrew each
time the IPS must be cycled.
This final rule adopts the proposed
rule with minor changes and adds
minor conforming changes to rules that
were added by the final rule entitled
‘‘Airplane Performance and Handling
Qualities in Icing Conditions (72 FR
44656, August 8, 2007) (Amendment
25–121).4 Amendment 25–121 added
specific requirements for airplane
performance and handling qualities for
flight in icing conditions. Sections
25.143(j) and 25.207(h), at Amendment
25–121, define requirements that apply
if activating the IPS depends on the
pilot seeing a specified ice accretion on
a reference surface (not just the first sign
of ice accretion).
Section 25.1419(e) of this final rule
requires one of three methods of
detecting icing and activating the
airframe IPS.5 Activation based on the
4 See Docket No. FAA–2005–22840 for complete
details.
5 The three methods are: (1) Primary ice detection
system, (2) visual cues of the first sign of ice
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
pilot seeing a specified ice accretion on
a reference surface (not just the first sign
of ice accretion) is not one of the three
methods allowed under this rulemaking,
so any requirements associated with this
method are no longer relevant.
Therefore, minor conforming changes
have been made to §§ 25.143(j) and
25.207(h) to remove the references to,
and requirements associated with,
activating the IPS in response to the
pilot seeing a specified ice accretion on
a reference surface. Additional minor
changes have been made to § 25.207(h)
to improve readability, including
moving a portion of existing
§ 25.207(h)(2)(ii) to a new § 25.207(i).
The text of part 25, appendix C, part
II(e) has been revised to include a
reference to the new § 25.207(i).
In addition, minor changes have been
made to § 25.207(b) to improve clarity
and to correct an error introduced by
Amendment 25–121. Section 25.207(b),
as amended by Amendment 25–121,
states, ‘‘Except for the stall warning
prescribed in paragraph (h)(2)(ii) of this
section, the stall warning for flight in
icing conditions prescribed in paragraph
(e) of this section must be provided by
the same means as the stall warning for
flight in non-icing conditions.’’
However, the stall warning prescribed
by § 25.207(h)(2)(ii) is an exception only
to the § 25.207(b) requirement that stall
warning in icing conditions be provided
by the same means as for non-icing
conditions. It is not an exception to, nor
is it associated with, the stall warning
margin prescribed by § 25.207(e). The
reference to § 25.207(e) is incorrect and
potentially confusing. Therefore, it is
removed by this final rule.
Because of the reformatting of
§ 25.207(h), as discussed above, the
previous § 25.207(h)(2)(ii) is now
§ 25.207(h)(3)(ii). The reference to this
paragraph in § 25.207(b) is changed
accordingly. Other minor wording
changes have been made to improve
clarity. We consider all of these changes
to § 25.207(b) to be technical
clarifications that do not change the
intent of this paragraph or impose an
additional burden on applicants.
Below is a more detailed discussion of
the rule as it relates to the comments we
received on the NPRM. Appendix 1
defines terms used in this preamble.
II. Summary of Comments
The FAA received 14 comments
concerning the following general areas
of the proposal:
accretion combined with an advisory ice detector,
and (3) specifying conditions conducive to airframe
icing.
PO 00000
Frm 00007
Fmt 4700
Sfmt 4700
38329
• Acceptable methods to determine if
the airframe IPS must be activated.
• Automatic cycling of the airframe
IPS.
Four of the commenters, the Airline
Pilots Association (ALPA), National
Transportation Safety Board (NTSB),
BAE Systems Regional Aircraft, and The
Boeing Company (Boeing), expressed
support for the rule. ALPA supported
the rule without recommendations to
revise the rule. Twelve commenters
suggested specific improvements or
clarifications. They were the NTSB,
BAE Systems Regional Aircraft, Boeing,
the Air Crash Victims Families Group,
Bombardier Aerospace, Marinvent
Corporation, the Regional Airline
Association, Swan International
Sensors, Transport Canada, and three
individuals. Ameriflight LLC
(Ameriflight) opposed certain
provisions of the rule. Summaries of the
comments and our responses (including
explanations of any changes to the final
rule in response to the comments) are
provided below.6
A. Ice Detection, Activation of Airframe
IPS, and Automatic Cycling of Airframe
IPS
In the NPRM, we proposed one of the
following three methods for ice
detection and activation of the airframe
IPS to ensure timely activation of the
airframe IPS (proposed § 25.1419(e)):
• A primary ice detection system that
automatically activates or alerts the
flightcrew to activate the airframe IPS;
• Visual cues for recognition of the
first sign of ice accretion combined with
an advisory ice detection system that
alerts the flightcrew to activate the
airframe IPS; or
• Identification of conditions
conducive to airframe icing for use by
the flightcrew to activate the airframe
IPS when those conditions exist.
In addition, proposed § 25.1419(g)
would require an airframe IPS that
operates cyclically (for example, deicing
boots) to automatically cycle after the
initial activation, or installation of an
ice detection system to alert the
flightcrew each time the deicing boots
must be activated.
The following comments were
received on these proposals.
1. Oppose Installation of an Ice
Detection System
Ameriflight opposed the installation
of an ice detection system because
properly trained flightcrews can easily
detect ice accretion by means such as
ice forming in the corners of the
6 The full text of each commenter’s submission is
available in the Docket.
E:\FR\FM\03AUR1.SGM
03AUR1
sroberts on DSKD5P82C1PROD with RULES
38330
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
windshield or on windshield wiper
arms. An individual commenter
believed nothing, including an ice
detector, can replace pilots looking out
the window to gather information on
icing.
Ameriflight also suggested that it
would be difficult or impossible to
design a sufficiently reliable ice
detection system that would be
economically feasible and a practicable
substitute for flightcrew training and
vigilance. The individual commenter
opposed installation of an ice detection
system because of his experience on a
military airplane that was equipped
with an unreliable icing warning light.
The FAA agrees that flightcrew
training and vigilance are extremely
important to ensure the safe operation of
aircraft in icing conditions. However,
visual observation of ice accretion
alone, as suggested by Ameriflight and
the individual commenter, is not
sufficient to ensure timely operation of
the airframe IPS. The flightcrew’s
observation of ice accretions can be
difficult during times of high workload,
nighttime operations, or when clear ice
has accumulated. In addition, there
have been icing accidents and incidents
where the flightcrew was either
completely unaware of ice accretion on
the airframe, or was aware of ice
accretion but judged that it was not
significant enough to warrant operation
of the airframe IPS. Therefore, reliance
on only flightcrew visual observation of
ice accretion alone is not adequate and
must be supplemented with an advisory
ice detection system to provide an
acceptable level of safety.
The FAA acknowledges that it is not
a simple task to design and certificate an
ice detection system. However, ice
detection systems exist today that meet
the reliability requirements of part 25.
Section 25.1309 ensures the degree of
reliability of an airframe IPS is
commensurate with the hazard level
associated with the failure of the
airframe IPS.
In response to the contention that an
ice detector would not be economically
feasible, the FAA notes that on recent
part 25 airplane certifications
manufacturers sought and received
approval for installation of ice detectors
without an FAA requirement for such a
system. Therefore, the FAA infers that
these manufacturers consider the
installation of ice detectors
economically feasible.
2. Reliability of Advisory Ice Detection
System
Transport Canada suggested that the
reliability level of the advisory ice
detection system should be on the order
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
of 1 × 10 5 failure per flight hour.
Transport Canada indicated the
classification assigned to the
unannunciated loss of an advisory ice
detection system would appear to
depend upon the advisory ice detection
system design, the IPS design, and the
airplane on which it is installed.
Therefore, it is Transport Canada’s
position that specific cases may need to
consider the unannunciated loss of the
advisory ice detection system as a major
failure. The natural tendency of
flightcrews to become accustomed to
using the advisory ice detection system
may increase the need to make
flightcrews aware of failure of the
advisory ice detection system. The
flightcrews may need to take extra
precautions when they have detected a
possible failure of the advisory ice
detection system.
The FAA infers that Transport Canada
would like the proposed rule changed to
include a minimum reliability
requirement for the advisory ice
detection system. The FAA finds it is
unnecessary to revise this rule to
include a minimum reliability
requirement for the advisory ice
detection system because § 25.1309
requires the determination of the hazard
level associated with failure of any
airplane system which then drives the
required degree of reliability of that
system. Additionally it would not be
appropriate to pick a specific minimum
reliability requirement for the advisory
ice detection system because, as pointed
out by the commenter, the hazard level
associated with the unannunciated loss
of the advisory ice detection system may
depend upon the advisory ice detection
system design, the airframe IPS design,
and the airplane on which it is installed.
However, the FAA may consider
including guidance on advisory ice
detection system reliability in the
associated advisory circular.
3. Do Not Activate Pneumatic Deicing
Boots at First Sign of Ice Accretion
Ameriflight did not support activation
of pneumatic deicing boots at the first
sign of ice accretion, noting that these
boots work better and continue to shed
ice more effectively for a longer period
if airfoil leading-edge ice is allowed to
build to a sufficient thickness before
cycling the boots. The commenter stated
that when the boots are operated at the
first indication of ice, the ice is only
partially shed. The ice remaining on the
boot provides a rough surface on which
additional ice accumulates more readily
than on a smooth boot surface,
shortening the duration of the boots’
PO 00000
Frm 00008
Fmt 4700
Sfmt 4700
ability to clean the wing effectively.7
Thus, the commenter believed that
activating the boots at the first sign of
ice was actually contrary to safety and
Ameriflight’s long experience with this
system.
The FAA has issued airworthiness
directives requiring activation of
pneumatic deicing boots early and
often. The airworthiness directives and
this rule address icing accidents and
incidents where the flightcrew was
either completely unaware of ice
accretion on the airframe, or was aware
of ice accretion but judged that it was
not significant enough to warrant
operation of the airframe IPS.
The commenter raised concerns over
residual ice, which is ice remaining (not
shed) after a complete boot cycle. The
FAA participated in high and low speed
icing wind tunnel tests that contradict
the commenter’s position that boots
work better, and continue to shed ice
effectively, for a longer period if airfoil
leading ice is allowed to build before
cycling the boots.
The higher speed icing wind tunnel
tests (≥180 KCAS) showed that ice was
shed after each boot activation and that
after 2 or 3 cycles there was no
discernible difference between ice
accretions from early versus delayed
activation of the boots. The residual ice
that remained on the boot after cycling
at the first sign of ice accretion was
always smaller than the amount of ice
that was present on the boot during the
time that it took for 1⁄4-inch of ice to
form.
The lower speed icing wind tunnel
tests (≤144 KCAS) showed large
amounts of residual ice which the boots
had difficulty shedding, regardless of
the activation method employed.
Immediate activation of an automatic
system did not degrade ice shedding
performance. Cycling early and often
resulted in shedding sooner than
waiting for a specified ice accretion
thickness. For example, simulating an
automatic one minute system activated
at first sign of icing at 14 °F, 108 KCAS,
resulted in a ‘‘good shed’’ at the 15th
cycle at 15 minutes. Waiting for a 1⁄4
inch accretion before cycling resulted in
a ‘‘good shed’’ at the 12th cycle at 20
minutes. The residual ice after ‘‘good
sheds’’ was similar regardless of the
boot activation method. Based on the
results of these tests, we do not agree
with Ameriflight’s position about the
7 The commenter noted that this is particularly
true of older boots that have been on the wing for
several seasons and which—although completely
airworthy—have leading edges which have become
somewhat roughened by the impacts of ice crystals,
snow, hail, etc., and provide a better ‘‘tooth’’ to
which structural ice can adhere.
E:\FR\FM\03AUR1.SGM
03AUR1
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
sroberts on DSKD5P82C1PROD with RULES
effectiveness of pneumatic deicing
boots.
4. Oppose Automatic Activation and
Cycling of Airframe IPS
Ameriflight also opposed any system
that would automatically activate ice
protection equipment or automatically
cycle pneumatic deicing boots.
Ameriflight suggested automatic
activation of deicing boots during low
speed operation, takeoff, or in the
landing flare could cause handling
quality problems on some aircraft. The
commenter stated that although such
automatic operation could be inhibited
by airspeed, landing gear position, or
other sensors, these in turn add
increments of complexity and potential
unreliability that tend to offset the
automatic systems’ safety value.
The FAA agrees that automatic
activation of the deicing boots during
some phases of flight (for example,
landing flare) could result in handling
quality problems on some airplanes. As
Ameriflight pointed out, inhibiting
automatic activation during these
phases of flight to prevent any handling
quality problems adds complexity to the
system and could potentially increase
the chances for the system not to
activate when it is needed. However, the
FAA finds that the increase in safety
afforded by automatic activation of the
airframe IPS outweighs the concerns
expressed by Ameriflight and that
compliance with other regulations
would mitigate those concerns.
Section 25.143(a) requires airplanes to
be safely controllable and maneuverable
during takeoff, climb, level flight,
descent, and landing. Section 25.143(b)
states that it must be possible to make
a smooth transition from one flight
condition to another without
exceptional piloting skill, alertness, or
strength under any probable operating
condition. If the airplane cannot operate
safely with the airframe IPS activated
during a particular phase of flight,
automatic activation of the airframe IPS
would need to be inhibited during that
phase of flight.
Any potential effect on the reliability
of the system to activate would be
assessed in accordance with § 25.1309,
which requires that systems must be
designed to perform their intended
function under any foreseeable
operating condition. Section 25.1309
also establishes the minimum allowable
system reliability, which is based on the
hazard that would result from failure of
the system. Therefore, the increase in
safety afforded by automatic activation
of the airframe IPS would not be offset
by the increase in complexity and
potential effect on reliability if
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
automatic activation must be inhibited
in certain flight phases.
Ameriflight commented that IPS other
than deicing boots should be controlled
by active involvement of the flightcrew,
rather than automatically. IPS operation
at inopportune times could actually
decrease safety, for example by causing
(i) preexisting ice accumulations to be
shed into engine inlets, (ii) undesired
drawdown of engine bleed air, or (iii) an
excess electrical load. Systems could be
designed with sensors to protect against
such inopportune operation, but only at
the price of additional complexity and
unreliability. Ameriflight opposed any
system that would automatically
activate ice protection equipment or
automatically recycle pneumatic deicing
boots because automatic systems may
fail, and the flightcrew might be
unaware the IPS is not operating.
‘‘Automatic’’ systems add complexity,
testing requirements, and systems
interfaces, and often result in decreased
overall reliability and tend to remove
the flightcrew from the operational loop.
The final rule does not require
automatic activation of airframe IPS, but
does allow it if a primary ice detection
system is installed. If an applicant
chooses to certificate a system to
activate the airframe IPS automatically,
compliance with part 25 regulations
ensure the airplane can operate safely
any time the airframe IPS is operated.
Issues raised by the commenter such as
ice shedding, bleed air, and electrical
power are considered during airplane
certification. As previously mentioned,
any system that would be necessary to
inhibit automatic activation would be
required to comply with § 25.1309,
which ensures system reliability
commensurate with the hazard
associated with the failure of that
system. As indicated by the commenter,
an automatic system may fail. However,
§ 25.1309 requires assessing the hazard
associated with the failure and
providing appropriate warnings
commensurate with the hazard.
Compliance with part 25 ensures the
safe operation of the airplane if the
airframe IPS is automatically activated
regardless of whether the airframe IPS is
a thermal anti-ice system or a deicing
boot system.
5. Necessity for Visual Cues in
Combination With an Advisory Ice
Detector
Bombardier noted the requirement for
an advisory system, in combination
with visual cues for recognition of ice
accretion, implies that visual cues are
necessary because of ice detector failure
and not ice detector performance. The
fact that no visual cues are necessary for
PO 00000
Frm 00009
Fmt 4700
Sfmt 4700
38331
a primary ice detection system (dual ice
detectors) seems to indicate an intent to
focus on ice detection failure. Therefore,
the commenter believed that it would be
appropriate to address how primary ice
detectors should be certified knowing
these potential limitations.
The FAA reviewed our airworthiness
directives that require operating deicing
boots at the first sign of ice accretion.
We determined that this means of IPS
operation should be improved because
such observations can be difficult
during times of high workload,
nighttime operations, or when clear ice
has accumulated. Therefore, to mitigate
the effects of human sensory limitations
and inadequate attention due to
workload, the final rule requires visual
cues of ice accretions in combination
with an advisory ice detector. The
combination of visual cues and advisory
ice detectors is intended to address the
potential limitations of human beings,
not of the ice detectors, as suggested by
the commenter. Limitations of primary
ice detectors, as well as advisory ice
detectors, are addressed during
certification through the requirements of
§§ 25.1301 and 25.1309. These
regulations require that equipment
function properly when installed,
perform its intended functions under
any foreseeable operation condition,
and ensure system reliability
commensurate with the hazard
associated with a failure of that system.
6. Require Automatic Activation of
Airframe IPS
An individual commenter requested
that § 25.1419(e) be revised to allow
only automatic activation of airframe
IPS in appendix C icing conditions, and
to require IPS status displays. The
commenter suggested that all other
proposed options to ensure timely
activation of the airframe IPS be deleted.
The commenter believed that visual
cues are not adequate, there is no
correlation between the ice formed on
the airframe and the thickness of the ice
formed on the ice detector, and
automatic activation would minimize
hazards by making flightcrews aware of
icing conditions early.
The FAA disagrees and maintains that
the proposed standard that allows
several means to ensure timely
activation of the airframe ice protection
equipment is acceptable. Icing accidents
and incidents do not support the
suggested revision. The FAA
acknowledges that automatic activation
of airframe IPS based on icing
conditions will likely result in earlier
activation and minimize the effects of
icing compared to waiting until ice
accretions have formed on the airframe.
E:\FR\FM\03AUR1.SGM
03AUR1
38332
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
sroberts on DSKD5P82C1PROD with RULES
However, later activation is acceptable,
provided an applicant substantiates the
airplane can operate safely with the ice
accretion present at the time the
airframe IPS is activated and becomes
effective. Consequently, if the airframe
IPS is activated based on an ice detector,
it is the ice accretion present on the
airframe that is important, not the
correlation between the ice shape on the
ice detector and the airframe. The
commenter pointed out icing accidents
and incidents where the flightcrew was
unaware of ice accretions and
concluded that visual cues are
inadequate. The FAA concurs that
visual cues alone are not adequate, but
visual cues in addition to an advisory
ice detection system would provide an
acceptable level of safety and mitigate
the effects of human sensory limitations
and inadequate attention due to
workload.
7. Remove Option To Activate Airframe
IPS Based on Temperature and Visible
Moisture
Proposed § 25.1419(e)(3) would allow
activation of the airframe IPS based on
conditions conducive to airframe icing
as defined by appropriate static or total
air temperature and visible moisture.
Three commenters, Transport Canada,
Swan International Sensors, and an
individual commenter did not consider
proposed § 25.1419(e)(3) an acceptable
alternative to requiring an ice detection
system. Transport Canada noted that it
is common to base temperature
indication on a single sensor, which
may not have the required reliability
and failure monitoring. Moreover, the
display of temperature may not be
conspicuous particularly on electronic
flight instrument systems. In addition, it
may not be easy to see visible moisture
at night. The commenter requested that
if paragraph (e)(3) is retained, it should
be limited to airplanes that are at a
lower risk of icing related incidents and
accidents. The individual commenter
stated that training flightcrews to
recognize conditions conducive to icing
is not an adequate solution because
such training and documentation have
existed for some time, yet icing related
accidents still occurred.
The FAA concludes that
§ 25.1419(e)(3) should be retained as
proposed because activation of the
airframe IPS using visible moisture and
temperature is based on the
methodology currently being used safely
for activating engine IPS. Flightcrews
are trained to recognize conditions
conducive to icing (that is, visible
moisture and temperature) and have
used this method safely for the
operation of engine IPS. While there
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
may be some challenges to observing
visible moisture at night, the challenge
is no different than for engine IPS
activation. The FAA expects that
activation of the airframe IPS using the
same type of cues will result in timely
activation just as it has for engines.
Furthermore, the accident and
incident history does not support the
commenter’s position that training
flightcrews to recognize conditions
conducive to icing has not been
successful. For airplanes with an
airframe IPS that is activated based on
visible moisture and temperature, the
FAA is unaware of accidents or
incidents attributed to the flightcrew not
activating the airframe IPS.
Regarding the concern over the
reliability of the current equipment used
to detect temperature, the equipment
must meet the requirements of
§ 25.1309. This could result in the need
to install different temperature sensing
equipment than what is used on aircraft
today.
8. Allow Temperature and Visible
Moisture in Combination With an
Advisory Ice Detection System
Transport Canada recommended the
FAA include temperature and visible
moisture in combination with an
advisory ice detection system as an
acceptable configuration under the
proposed rule.
The FAA determines there is no need
to revise the rule to explicitly provide
the suggested option. The regulations
provide minimum requirements and an
applicant has the option of exceeding
these requirements. Therefore, even
though the suggested option is not
identified in the proposed rule, it would
be acceptable for an applicant to comply
with proposed § 25.1419(e)(3) and
voluntarily go beyond that requirement
and install an advisory ice detection
system.
9. Need Definition of Environmental
Conditions Conducive to Icing
The National Transportation Safety
Board (NTSB) commented that industry
could not realistically be expected to
implement § 25.1419(e)(3) until the FAA
provides a more specific definition of
‘‘environmental conditions conducive to
icing.’’ Swan International Sensors
stated that the flightcrew would be
required to interpret icing conditions
because they are not defined adequately
by paragraph (e)(3).
The FAA concludes that the proposed
rule adequately defined environmental
conditions conducive to icing and does
not require interpretation by the
flightcrew. The rule requires the
manufacturer to identify conditions
PO 00000
Frm 00010
Fmt 4700
Sfmt 4700
conducive to airframe icing as defined
by an appropriate static or total air
temperature and visible moisture for use
by the flightcrew to activate the airframe
IPS. The proposed rule defined the
environmental conditions as a static or
total air temperature and visible
moisture. Advisory circular (AC) 25–
1419–2, Compliance with the Ice
Protection Requirements of
§§ 25.1419(e), (f), (g), will provide
guidance on determining the
temperature cue. Therefore, we made no
changes to proposed § 25.1419(e)(3) in
this final rule.
10. Require Aircraft Be Equipped With
All Three Proposed Methods of
Airframe Ice Detection
The proposed § 25.1419(e) would
require one of three ice detection and
activation methods. The Air Crash
Victims Families Group and an
individual commenter requested that
the final rule require all three ice
detection and activation methods
identified in proposed § 25.1419(e). The
commenters also requested that the FAA
require automatic ice detection systems
to warn pilots of icing and to activate
IPS automatically. The commenters
referenced the Circuit City airplane
accident in Pueblo, Colorado, on
February 16, 2005, where the NTSB
found the probable cause to be the
flightcrew’s failure to monitor and
maintain airspeed and comply with
procedures for ice boot activation on
approach.8 In addition, the NTSB found
that distractions impeded the
flightcrew’s ability to monitor and
maintain airspeed and manage the
deicing system.
The FAA finds that icing accidents
and incidents do not support the
commenters’ suggestion to require all
three proposed methods to ensure
timely activation of the airframe IPS or
require a system to activate the airframe
IPS automatically. The three proposed
methods would independently ensure
timely activation of the airframe IPS.
The FAA is unaware of any icing
accidents or incidents attributed to
untimely activation of the airframe IPS
on an airplane that had equipment
compliant with this rule. The flightcrew
of the Circuit City airplane relied on
visual observation of ice accretions for
determining if the airframe IPS should
be activated and cycled manually. There
was not a detector to tell the flightcrew
to cycle the airframe IPS. This rule
requires an advisory ice detection
8 The commenter noted that the Cessna Citation
560 was equipped with deice boots that do not
cycle automatically, which require pilots to
continually monitor accumulation and reactivate
the deice boots each time.
E:\FR\FM\03AUR1.SGM
03AUR1
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
system in addition to visual observation
of the first sign of ice accretion as a
means to determine the airframe IPS
must be activated. In addition, the rule
addresses flightcrew workload by
requiring deice boots to automatically
cycle or by equipping the airplane with
an ice detection system to alert the
flightcrew each time the airframe IPS
must be cycled. For these reasons, the
suggested revisions are not being
adopted.
11. Require Manual Back-Up to
Automatic Activation of Airframe IPS
Proposed § 25.1419(g) addressed the
flightcrew workload associated with an
airframe IPS that operates cyclically and
that requires continuous monitoring of
ice accretions to determine when to
activate the IPS. Proposed paragraph
(g)(2) requires that these systems
automatically cycle the airframe IPS to
eliminate the need to continuously
monitor ice accretions. An individual
commenter requested that proposed
paragraph (g) be revised to require
manual system activation as a back-up
to automatic activation. Compliance
with § 25.1309, which requires an
assessment of the hazard associated
with the failure of a system, will
determine whether a manual system is
required as a back-up to an automatic
activation system. Therefore, the FAA
finds it is unnecessary to require a backup manual system as suggested by the
commenter.
sroberts on DSKD5P82C1PROD with RULES
12. Allow an Aerodynamic Performance
Monitoring System
Marinvent and the Regional Airline
Association requested revising the
proposed rule to include an
aerodynamic performance monitoring
(APM) system as an alternative to ice
detection systems.9 The commenters
believed APMs have several advantages
over ice detectors, but that they do not
inherently detect ice. Therefore, the
proposed rule text did not directly
address APMs because they are not
strictly ‘‘ice detection systems.’’ The
commenters understood that applicants
may propose the APM as an alternative
means of compliance by demonstrating
an equivalent level of safety. However,
the commenters thought the process of
obtaining an equivalent level of safety
finding would discourage the use of this
alternative and believed there was a
fundamental conceptual difference
between the ice detection and
aerodynamic monitoring, making it
9 Aerodynamic performance monitoring systems
directly measure the degradation of airfoil
performance caused by the roughness and profile
changes induced by the contamination of the airfoil.
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
difficult for the applicant and the
regulator to establish common ground to
demonstrate an equivalent level of
safety. The commenters contended the
existing proposed rule text would
effectively exclude the APM systems as
a viable alternative means of
compliance with the regulation.
The Regional Airline Association
added that at least one of their associate
members currently provides an APM
system as an option in their aircraft
(Aerospatiale model ATR 72) for their
airline members.
The FAA concludes that, at this time,
APMs are not sufficiently mature to use
as a method to ensure timely activation
of the airframe IPS. Further, contrary to
the commenters’ beliefs, the equivalent
level of safety process is commonly
used in certification programs and
would not discourage the use of
alternatives such as an APM.
In response to the Regional Airline
Association’s comment that an APM is
currently offered as an option on the
Aerospatiale ATR 72 aircraft, the FAA is
aware that Aerospatiale has certificated
an aircraft performance monitor, not an
aerodynamic performance monitor. The
aircraft performance monitor system
used on the ATR 72 is intended to
provide the flightcrew with information
that could help them manage a severe
icing encounter. The ATR 72’s aircraft
performance monitor system is not
intended, nor certificated, to provide the
flightcrew with information to ensure
the airframe IPS is activated in a timely
manner.
B. Airframe Ice Protection System
Operation
Proposed § 25.1419(f) would allow an
applicant to substantiate that the
airframe IPS need not be operated
during specific phases of flight. An
individual commenter requested that
§ 25.1419(f) be revised to allow airplane
operations with the IPS inactive if the
airplane can be operated safely with the
ice accretions associated with probable
failures. The commenter also requested
that § 25.1419(f) be revised to require
that safe operation be demonstrated by
flight test, icing tunnel tests, or other
means.
The FAA finds the suggestion to
consider only the ice accretions
associated with probable failures
unacceptable. Compliance with
§ 25.1309 determines the failures that
must be considered, and this rule
should not predetermine that only
probable failures need be considered.
Regarding the suggestion to specify the
acceptable means of showing
compliance, the FAA finds it is not
necessary because § 25.1419(a) and (b)
PO 00000
Frm 00011
Fmt 4700
Sfmt 4700
38333
already specify the means that can be
used to substantiate that an airplane can
operate safely in icing conditions. For
these reasons, the FAA did not adopt
the suggested changes to § 25.1419(f).
C. Airplane Flight Manual Requirements
Proposed section § 25.1419(h) would
require that procedures for operation of
the IPS be established and documented
in the Airplane Flight Manual (AFM).
BAE Systems Regional Aircraft
requested the word ‘‘airframe’’ be added
to § 25.1419(h). The FAA finds that
adding the word ‘‘airframe’’ to
§ 25.1419(h) is not necessary because
the procedures for operation of both
engine and airframe IPS must be in the
AFM. Traditionally, manufacturers
provide adequate information in the
AFM regarding the operation of the
engine IPS, but information for an
airframe IPS is sometimes lacking or is
not consistent with the methods of
operation used during certification.
Proposed paragraph (h) is included to
ensure future AFMs also include
information for the operation of airframe
IPS.
Another commenter requested that
§ 25.1419(h) be deleted because the
requirement is already covered by the
existing regulation in the section titled
‘‘Airplane Flight Manual.’’
The FAA finds that the sections
relating to the AFM in part 25, Subpart
G (§§ 25.1581–25.1587) do not explicitly
address IPS operations. Therefore, the
Subpart G regulations must be
supplemented with the proposed
§ 25.1419(h) to ensure that procedures
for operating the IPS are included in the
AFM and are consistent with the
requirements of § 25.1419. For these
reasons, the suggested revision is not
being adopted in this final rule.
Boeing requested that proposed
§ 25.1419(g)(1) be changed to require
that the IPS must operate continuously
only while the aircraft remains in icing
conditions. The proposed rule would
require operating the anti-icing system
continuously throughout a potentially
long flight after exiting icing conditions.
Such continued operation while not in
icing conditions is not necessary and
wastes fuel. Boeing suggested that the
proposed rule be revised to specify
when an IPS that operated continuously
can be deactivated.
Based on Boeing’s comment, it
appears the intent of § 25.1419(g) may
be unclear. Proposed § 25.1419(g)
provided three options to minimize the
flightcrew workload associated with
airframe IPS operation. One option
(§ 25.1419(g)(1)) is an airframe IPS that
operates continuously. Section
25.1419(g)(1) has been revised to clarify
E:\FR\FM\03AUR1.SGM
03AUR1
38334
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
that the airframe IPS must be designed
to operate continuously, not to require
continuous operation of an airframe IPS.
We also clarified that procedures for
operation of the IPS as specified in
§ 25.1419(h) include both activation and
deactivation procedures. In addition, we
revised § 25.1419(g)(1) to say that the
IPS must be designed to operate
continuously.
For future certification programs (as
with past certification programs), it is
incumbent upon the manufacturer to
propose and substantiate when it is
acceptable to deactivate the IPS. The
only difference from past certifications
will be that the activation requirements
of § 25.1419(e) must be considered.
D. Other Comments
1. Clarify the Rule Is Applicable to
Airframe IPS
BAE Systems Regional Aircraft
requested that § 25.1419(f) and (g) be
modified to indicate the ‘‘airframe’’ IPS
are being referenced.
The FAA agrees that §§ 25.1419(f) and
(g) should be clarified by adding the
word ‘‘airframe.’’ Therefore, in
§ 25.1419(f), we revised the introductory
language to reference the airframe IPS
(‘‘Unless the applicant shows that the
airframe ice protection system * * *).
In § 25.1419(g), we made a similar
revision to the introductory language
(‘‘After the initial activation of the
airframe ice protection system * * *).
sroberts on DSKD5P82C1PROD with RULES
2. Expand Rule To Include Certain
Existing Airplanes and Prohibitions
With IPS Inoperable
The NTSB requested a revision to
address its perceived ongoing
disconnect between the industry’s
guidance on deicing boot activation and
what the FAA has learned and research
has shown regarding ice bridging and
deice boot effectiveness. The NTSB
noted the Cessna 208 Caravan AFM
instructs crews to wait for 1⁄4 to 3⁄4 inch
of ice to accrete before activating the
pneumatic deicing boots.
The FAA finds that for the new part
25 airplane and for existing part 25
airplanes that are modified in the future
with significant airframe IPS design
changes, this rule precludes the
potential for perpetuating the belief that
flightcrews should wait for a specific
amount of ice to accumulate before
activating the deicing boots. The final
rule requires activation of the airframe
IPS based on ice detectors or icing
conditions and requires procedures for
operating the IPS in the AFM.
Therefore, for new part 25 airplanes, the
industry guidance in the AFM will
reflect the FAA regulatory requirements
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
for activation of the IPS which does not
allow activation of deicing boots based
on the flightcrew determining that a
specified thickness of ice has
accumulated.
The NTSB, Air Crash Victims
Families Group, and one other
commenter requested the proposed rule
be expanded to include existing
airplanes equipped with pneumatic
deicing boots and reference the NTSB
safety recommendations A–98–91, A–
98–100, A–07–14, and A–07–16 (which
recommend icing related actions the
FAA should take for existing airplanes).
We disagree. The NPRM did not
address this issue, and revising this
final rule to include retrofit
requirements for existing airplanes
would delay its issuance, which is not
in the interest of safety. However, the
FAA may consider additional
rulemaking to address activation of the
IPS on part 121 airplanes at a later date.
The NTSB also believed the proposed
rule should prohibit crews from
operating the airplane when certain
functions of the IPS are inoperable, and
should prohibit flight into known icing
conditions if certain functions of the IPS
are inoperable.
The FAA maintains that if certain
equipment is inoperable, transport
category airplanes should be prohibited
from flight in forecasted icing
conditions in addition to prohibiting
flight in known icing conditions (as
suggested by the NTSB). However, we
do not concur with incorporating such
a requirement into a certification rule.
The FAA utilizes the Master Minimum
Equipment List (MMEL) to evaluate
whether an airplane may be operated
with a particular piece of equipment
inoperative. Each airplane is unique and
the MMEL is the best way to determine
the impact of an inoperable piece of
equipment.
3. Revise Rule To Encourage Specific
Airfoil Designs
The Regional Airline Association
noted that several aircraft types over
many years have been operated safely
without any incidents or accidents
attributed to icing. The commenter
requested the proposed rule be rewritten
to encourage airfoil design as the best
means to address safety concerns due to
operations in icing conditions.
Although the FAA does not write
regulations to ‘‘encourage’’ specific
airfoil designs, we do establish the
performance and handling requirements
an airplane must meet to substantiate
that the airplane can operate safely in
icing conditions. These safety
requirements (to a certain extent) drive
the design of the airfoil. However, it is
PO 00000
Frm 00012
Fmt 4700
Sfmt 4700
the responsibility of the airframe
manufacturer to design an airplane that
meets the Federal Aviation Regulations
icing regulations.
E. Economic Analysis
An individual commenter stated that
the Goodrich Corporation cost estimates
identified in the NPRM appear to be
realistic, but the non-recurring costs
could be reduced by a system that uses
a detector that is different than the
assumed ice detector. The commenter
suggested using a ‘‘universal’’ sensor or
detector that is independent of the
airplane type and installation location;
like a pressure sensor, a temperature
sensor, a humidity sensor, or a system
that consists of sensors that are
universal.10
The commenter provided cost
estimates that are less than the ice
detector certification estimates used in
our economic assessment. However,
even with the more costly estimates, the
FAA concluded the economic impact of
the rulemaking is minimal. Since
decreasing the cost estimates would not
affect this conclusion, the FAA has
determined it is not necessary to revise
the costs in our economic assessment.
The FAA requested comments from
U.S. manufacturers on their plans to
produce a new part 25 certificated
aircraft with deicing systems that
operate cyclically and the associated
certification costs. Bombardier and
Transport Canada referenced this FAA
request, but did not provide any data.
Bombardier believes the FAA’s
economic analysis, which noted the
trend of part 25 manufacturers to install
thermal anti-ice protection systems in
newly certificated part 25 airplanes,
implied that the FAA considered
‘‘cyclical’’ deicing systems to be
anachronistic. Bombardier indicated
that technology in development may
reintroduce cyclical deicing systems.
Transport Canada indicated that if
cyclical deicing systems are being
considered for the future, then the FAA
trend noted in the NPRM would not be
correct.
While technology development may
result in the reintroduction of cyclical
deicing systems in the future, the FAA
is unaware of any actual plans to
produce a new part 25 certificated
aircraft with deicing systems that
operate cyclically and the associated
certification costs. Without such
information, we believe the economic
assessment stating that the trend for
10 The commenter estimated the non-recurring
costs could be: Architecture/integration $7,500,
qualification testing $10,000, system certification
$50,000, and installation design $5,000.
E:\FR\FM\03AUR1.SGM
03AUR1
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
new part 25 aircraft certifications is
toward thermal anti-ice ice protection
systems is accurate.
Paperwork Reduction Act
The Paperwork Reduction Act of 1995
(44 U.S.C. 3507(d)) requires that the
FAA consider the impact of paperwork
and other information collection
burdens imposed on the public. We
have determined that there is no current
or new requirement for information
collection associated with this
amendment.
sroberts on DSKD5P82C1PROD with RULES
International Compatibility
In keeping with U.S. obligations
under the Convention on International
Civil Aviation, it is FAA policy to
comply with International Civil
Aviation Organization (ICAO) Standards
and Recommended Practices to the
maximum extent practicable. The FAA
has determined that there are no ICAO
Standards and Recommended Practices
that correspond to these regulations.
III. Regulatory Evaluation, Regulatory
Flexibility Determination, International
Trade Impact Assessment, and
Unfunded Mandates Assessment
Changes to Federal regulations must
undergo several economic analyses.
First, Executive Order 12866 directs that
each Federal agency shall propose or
adopt a regulation only upon a reasoned
determination that the benefits of the
intended regulation justify its costs.
Second, the Regulatory Flexibility Act
of 1980 (Pub. L. 96–354) requires
agencies to analyze the economic
impact of regulatory changes on small
entities. Third, the Trade Agreements
Act (Pub. L. 96–39) prohibits agencies
from setting standards that create
unnecessary obstacles to the foreign
commerce of the United States. In
developing U.S. standards, this Trade
Act requires agencies to consider
international standards and, where
appropriate, that they be the basis of
U.S. standards. Fourth, the Unfunded
Mandates Reform Act of 1995 (Pub. L.
104–4) requires agencies to prepare a
written assessment of the costs, benefits,
and other effects of proposed or final
rules that include a Federal mandate
likely to result in the expenditure by
State, local, or Tribal governments, in
the aggregate, or by the private sector, of
$100 million or more annually (adjusted
for inflation with base year of 1995).
This portion of the preamble
summarizes the FAA’s analysis of the
economic impacts of this final rule.
An assessment has been conducted of
the economic cost impact of the final
rule amending § 25.1419 of Title 14 of
the Code of Federal Regulations (14
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
CFR) part 25, and we have determined
the final rule has minimal costs. This
final rule is the result of information
gathered from a review of historical
icing accidents and incidents. It is
intended to improve the level of safety
when part 25 airplanes are operated in
icing conditions.
Amendment 25–121 revised § 25.207
to add requirements for considering the
effects of icing on stall warning. At the
time we issued Amendment 25–121, it
was permissible for type certificate
applicants to instruct pilots to wait for
a specified amount of ice accretion to
accumulate before activating the ice
protection system (IPS). Section
25.207(h)(1), as adopted in Amendment
25–121, addressed this scenario by
requiring flight testing with the
specified amount of ice accretion to
show the airplane could be operated
safely until the IPS is functioning. This
rule will prohibit use of this method for
activating the IPS. Therefore, there is no
longer any need to have the existing
provision § 25.207(h)(1) that provides
stall warning margin requirements for
this method, and we are removing those
provisions from § 25.207. This is a
conforming change, and does not add
any new requirements or costs. In
addition, § 25.207 has been revised to
improve its readability and to correct an
error introduced by Amendment 25–
121, but none of these revisions affect
the substantive requirements.
This final rule requires newly
certificated part 25 transport category
airplanes certificated for flight in icing
conditions to have one of the following
methods to detect ice and activate the
airframe IPS:
• A primary ice detection system,
automatic or manual;
• The definition of visual cues for
recognition of ice accretion on a
specified surface combined with an
advisory ice detection system that alerts
the flightcrew; or
• The identification of icing
conditions by an appropriate static or
total air temperature and visible
moisture cues.
The FAA did not receive comments
causing us to change our NPRM
determination that the expected costs
are minimal. Bombardier indicated
future technology may reintroduce
cyclical deicing systems. Since 1971, no
U.S. manufacturer has certificated
cyclical deicing systems. Also, recent
part 23 Very Light Jet (VLJ) certification
programs have automatic cyclical
deicing systems. We do not anticipate
manufacturers to certificate manuallycycled deicing systems.
PO 00000
Frm 00013
Fmt 4700
Sfmt 4700
38335
A. Cost Discussion
1. Major Assumptions
This evaluation makes the following
assumptions:
• We used a $50 hourly rate for a
mechanic/technician and a $75 hourly
rate for an engineer working for an
airplane manufacturer or modifier.
• Whenever various compliance
options are available to the
manufacturers, we chose the least costly
option in our analysis.
Other data and derived assumptions
are discussed in the following sections
on costs and benefits.
2. Estimate of Costs
This section discusses the costs of a
new requirement for transport category
airplane manufacturers to include a
method of ice detection on newly
certificated airplanes. The cost estimate
included below is not an estimate per
manufacturer, rather an estimate per
new part 25 airplane certification.
This final rule will require
manufacturers of part 25 airplanes to
provide the flightcrew with an effective
method of ice detection. Such a method
can provide a means, using an ice
detection system (IDS), to alert the
flightcrew of icing conditions and
enable timely activation of the airframe
IPS for the initial and any subsequent
cycles.
The requirements for ice detection
and activation of the airframe IPS are
applicable to all phases of flight, unless
it can be shown that the airframe IPS
need not be operated during specific
phases of flight. If the airframe IPS
operates in a cyclical manner, it must
either include a system that
automatically cycles the airframe IPS, or
there must be a method that alerts the
flightcrew each time the airframe ice
protection system must be cycled. This
final rule requires:
• (e)(1) A primary IDS that
automatically activates or alerts the
flightcrew to activate the airframe IPS;
• (e)(2) A definition of visual cues for
recognition of the first sign of ice
accretion on a specified surface
combined with an advisory IDS that
alerts the flightcrew to activate the
airframe IPS; or
• (e)(3) Identification of conditions
conducive to airframe icing as defined
by an appropriate static or total air
temperature and visible moisture for use
by the flightcrew to activate the airframe
IPS.
Any of the three ice detection
methods will enable timely activation of
the airframe IPS and satisfy the
requirements of this final rule.
E:\FR\FM\03AUR1.SGM
03AUR1
38336
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
The first method of ice detection is
the use of a primary IDS. A primary IDS
usually has two ice detectors. The cost
of an ice detector used in this analysis
is based on the Goodrich Corporation’s
average price of $6,000 per ice detector
for a production airplane. The Aviation
Rulemaking Advisory Committee
(ARAC) Ice Protection Harmonization
installation, or $14,500 ($12,000 +
$2,500) per airplane. Table 1 shows a
detailed breakout of these cost
estimates.
One commenter to the NPRM,
regarding Goodrich costs, stated there
was a cheaper alternative system than
the Goodrich system. The FAA notes a
lower cost alternative is feasible.
Working Group provided us with
manufacturer cost estimates for System
Design, System Qualification, Hardware,
Installation, and Maintenance.
Assuming the primary IDS has two ice
detectors, we estimate the average cost
for a primary IDS to be about $485,000
per certification, $12,000 ($6,000 × 2)
for the hardware and $2,500 for the
TABLE 1—COSTS FOR § 25.1419(E)(1)—PRIMARY ICE DETECTION SYSTEM
Manufacturer non-recurring costs (per aircraft group/type) 2006$
Hours
System Design:
System architecture/Integration ................................................................................
Ice detector positioning ............................................................................................
Procedures for AFM, AOM/FCOM & MMEL ............................................................
System Qualification/certification:
Ice detector qualification ...........................................................................................
Ice detection system certification .............................................................................
Flight tests ................................................................................................................
Installation Design:
Installation drawings .................................................................................................
Hourly rate
Additional
cost
Cost
3,000
300
200
$75
75
75
....................
....................
....................
$225,000
22,500
15,000
300
600
400
75
75
75
....................
....................
100,000
22,500
45,000
130,000
500
50
....................
25,000
Total ...................................................................................................................
5,300
....................
....................
485,000
Costs (per airplane):
Hardware (Primary Ice Detection System) ...............................................................
Installation .................................................................................................................
Additional weight is 5–10 kg ....................................................................................
....................
50
....................
....................
50
....................
12,000
....................
....................
12,000
2,500
0
Total ...................................................................................................................
....................
....................
....................
14,500
The second method of ice detection is
the use of an advisory IDS along with
visual cues. The major difference
between a primary and an advisory IDS
is that the primary is the principal
means to determine when the airframe
hardware and $1,250 for the
installation, or $7,250 ($6,000 + $1,250)
per airplane. Table 2 shows a detailed
breakout of these costs estimates.
IPS should be activated and has two ice
detectors. In contrast, an advisory IDS is
a backup to the flightcrew and has only
one ice detector. The average cost for an
advisory IDS is estimated to be $447,500
per certification, $6,000 for the
TABLE 2—COSTS FOR § 25.1419(E)(2)—ADVISORY ICE DETECTION SYSTEM AND VISUAL CUES
Manufacturer non-recurring costs (per aircraft group/type) 2006$
Hours
System Design:
System architecture/Integration ................................................................................
Ice detector positioning ............................................................................................
Visual cue determination/design ..............................................................................
Procedures for AFM, AOM/FCOM & MMEL ............................................................
System Qualification/certification:
Ice detection qualification .........................................................................................
Visual cue substantiation ..........................................................................................
Ice detection system certification .............................................................................
Flight tests ................................................................................................................
Installation Design:
Installation drawings .................................................................................................
Hourly rate
Additional
cost
Cost
$75
75
75
75
....................
....................
....................
....................
$187,500
15,000
15,000
15,000
300
200
300
400
75
75
75
75
....................
....................
....................
$100,000
22,500
15,000
22,500
130,000
500
50
....................
25,000
Total ...................................................................................................................
sroberts on DSKD5P82C1PROD with RULES
2,500
200
200
200
4,800
....................
....................
447,500
Costs (per airplane):
Hardware (Advisory Ice Detection System) .............................................................
Installation .................................................................................................................
Additional weight is 5–10 kg ....................................................................................
....................
25
....................
....................
50
....................
6,000
....................
....................
6,000
1,250
0
Total ...................................................................................................................
....................
....................
....................
7,250
The third method of ice detection is
a definition of conditions conducive to
VerDate Nov<24>2008
16:34 Jul 31, 2009
Jkt 217001
airframe icing that will be used by the
flightcrew to activate the airframe IPS.
PO 00000
Frm 00014
Fmt 4700
Sfmt 4700
This definition will be included in the
Airplane Flight Manual. There are no
E:\FR\FM\03AUR1.SGM
03AUR1
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
costs imposed on the airplane
manufacturers with this option. Table 3
38337
shows a summary of the costs for each
alternative.
TABLE 3—COST SUMMARY—§ 25.1419(E)
Costs
Per certification
§ 25.1419 Alternatives:
(e)(1) Primary IDS ..................................................................................................................................
(e)(2) Advisory IDS and Visual Cues .....................................................................................................
(e)(3) Temperature and Moisture ...........................................................................................................
The least cost alternative is to activate
the airframe IPS whenever the airplane
is operating in conditions conducive to
airframe icing based on a specific air
temperature threshold and the presence
of visible moisture. Since there are no
additional certification or production
costs to manufacturers by complying
with § 25.1419(e)(3) through this
alternative, we have determined there
are no costs associated with compliance
with § 25.1419(e).
We are aware some manufacturers
may choose to install more complex
systems ((e)(1) or (e)(2)), and want to
note these more complex systems are
acceptable alternatives to (e)(3).
§ 25.1419(f)
Section 25.1419(f) describes the
applicability of the final rule to all
phases of flight, so there are no
additional costs associated with this
section.
sroberts on DSKD5P82C1PROD with RULES
§ 25.1419(g)
After the initial operation of the
airframe IPS, § 25.1419(g) provides
alternatives the manufacturer must
provide to the operator for safe flight.
These alternatives are:
• The IPS must be designed to
operate continuously (§ 25.1419(g)(1)),
or
• The airplane must be equipped
with a system that automatically cycles
the IPS (§ 25.1419(g)(2)), or
• An IDS must be provided to alert
the flightcrew each time the IPS must be
cycled (§ 25.1419(g)(3)).
Section 25.1419(g) applies to
airplanes with either a thermal antiicing IPS or an IPS that operates in a
cyclical manner. Thermal anti-icing
systems typically operate continuously
while deicing systems usually operate
cyclically.
Section 25.1419(g)(1) applies
primarily to a thermal anti-icing IPS,
which typically uses heat to keep
protected surfaces of the airplane free of
ice accretions.
No additional manufacturing costs are
associated with § 25.1419(g)(1) because,
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
once a thermal anti-IPS is activated, it
is capable of operating continuously.
The cost estimates for each option do
not include primary and advisory ice
detection system maintenance, which
would make the costs for these
alternatives higher. The FAA has
determined that the trend for new part
25 aircraft certification is toward antiice protection systems so the
maintenance costs associated with
deicing ice protection systems are not
considered. The cost estimates for
§ 25.1419(g)(1) do not include the
associated maintenance costs for antiice protection systems as operators are
already incurring these costs.
Sections 25.1419(g)(2) and (3) apply
to an airframe IPS that operates in a
cyclical manner. Past delivery history
has shown that about 97% of U.S.
manufactured part 25 airplanes
delivered have thermal anti-icing IPS
and 3% have deicing IPSs that operate
in a cyclical manner. Cessna is the only
U.S. manufacturer that currently
delivers part 25 certificated airplanes
with an IPS that operates in a cyclical
manner. Those airplanes were
certificated in September 1971.11 Newer
variants of airplanes from that
September 1971 type certificate and all
newer part 25 new Cessna certifications
have thermal anti-icing IPS that operate
continuously. We believe the trend for
new part 25 aircraft certifications is
toward a thermal anti-icing IPS that
operates continuously. Because of the
trend of part 25 manufacturers to install
thermal anti-icing IPS in their newly
certificated part 25 airplanes, we believe
there are no costs imposed on the
airplane manufacturers by § 25.1419(g).
Bombardier indicated future
technology may reintroduce cyclical
deicing systems. No U.S. manufacturer
has certificated cyclical deicing systems
since 1971. Since recent part 23 Very
Light Jet (VLJ) certification programs
have automatic cyclical deicing systems,
we do not anticipate airplane
manufacturers to certificate manuallycycled deicing systems.
PO 00000
11 Type
Certification Data Sheet No. A22CE.
Frm 00015
Fmt 4700
Sfmt 4700
$485,000
447,500
0
Per airplane
$14,500
7,250
0
We received no comments from U.S.
manufacturers on their plans to produce
a newly part 25 certificated aircraft with
deicing systems that operate cyclically
and the associated certification costs;
therefore, we believe § 25.1419(g) will
add no additional costs.
§ 25.1419(h)
Future Airplane Flight Manuals can
be readily prepared to include
appropriate icing procedures for future
certificated air transport category
airplanes. Thus, minimal costs are
associated with § 25.1419(h).
B. Benefits
The FAA is adopting this final rule
because accidents and incidents
occurred where the flightcrew did not
operate the airframe IPS in a timely
manner and because of concerns over
the flightcrew workload required to
operate an airframe IPS that the
flightcrew must manually cycle. The
final rule addresses these concerns by
ensuring that flightcrews are provided
with a clear means to know when to
activate the airframe IPS and by
reducing the workload associated with
an airframe IPS that operates cyclically.
The safety benefit of this final rule is
that it will improve the level of safety
of new airplane designs for operations
in icing conditions.
C. Conclusions
The FAA has determined that this
final rule has benefits that justify its
minimal costs. However, the Office of
Management and Budget has
determined that this final rule is a
‘‘significant regulatory action,’’ because
it harmonizes U.S. aviation standards
with those of other civil aviation
authorities.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980
(Pub. L. 96–354) (RFA) establishes ‘‘as a
principle of regulatory issuance that
agencies shall endeavor, consistent with
the objectives of the rule and of
applicable statutes, to fit regulatory and
informational requirements to the scale
E:\FR\FM\03AUR1.SGM
03AUR1
38338
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
sroberts on DSKD5P82C1PROD with RULES
of the businesses, organizations, and
governmental jurisdictions subject to
regulation. To achieve this principle,
agencies are required to solicit and
consider flexible regulatory proposals
and to explain the rationale for their
actions to assure that such proposals are
given serious consideration.’’ The RFA
covers a wide-range of small entities,
including small businesses, not-forprofit organizations, and small
governmental jurisdictions.
Agencies must perform a review to
determine whether a rule will have a
significant economic impact on a
substantial number of small entities. If
the agency determines that it will, the
agency must prepare a regulatory
flexibility analysis as described in the
RFA.
However, if an agency determines that
a rule is not expected to have a
significant economic impact on a
substantial number of small entities,
section 605(b) of the RFA provides that
the head of the agency may so certify
and a regulatory flexibility analysis is
not required. The certification must
include a statement providing the
factual basis for this determination, and
the reasoning should be clear.
As we stated in the NPRM, all United
States transport category aircraft
manufacturers exceed the Small
Business Administration small-entity
criteria of 1,500 employees. We received
no public comments disputing this
determination. Therefore, as the FAA
Administrator, I certify that this rule
will not have a significant economic
impact on a substantial number of small
entities.
International Trade Impact Assessment
The Trade Agreements Act of 1979
(Pub. L. 96–39) prohibits Federal
agencies from establishing any
standards or engaging in related
activities that create unnecessary
obstacles to the foreign commerce of the
United States. Legitimate domestic
objectives, such as safety, are not
considered unnecessary obstacles. The
statute also requires consideration of
international standards and, where
appropriate, that they be the basis for
U.S. standards. The FAA has assessed
the potential effect of this final rule and
has no basis for believing the rule will
impose substantially different costs on
domestic and international entities.
Thus the FAA believes the rule has a
neutral trade impact.
Unfunded Mandates Assessment
Title II of the Unfunded Mandates
Reform Act of 1995 (Pub. L. 104–4)
requires each Federal agency to prepare
a written statement assessing the effects
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
of any Federal mandate in a proposed or
final agency rule that may result in an
expenditure of $100 million or more (in
1995 dollars) in any one year by State,
local, and Tribal governments, in the
aggregate, or by the private sector; such
a mandate is deemed to be a ‘‘significant
regulatory action.’’ The FAA currently
uses an inflation-adjusted value of
$136.1 million in lieu of $100 million.
This final rule does not contain such a
mandate; therefore, the requirements of
title II of the Act do not apply.
Executive Order 13132, Federalism
The FAA has analyzed this final rule
under the principles and criteria of
Executive Order 13132, Federalism. We
determined that this action will not
have a substantial direct effect on the
States, or the relationship between the
Federal Government and the States, or
on the distribution of power and
responsibilities among the various
levels of government, and, therefore,
does not have federalism implications.
Regulations Affecting Intrastate
Aviation in Alaska
Section 1205 of the FAA
Reauthorization Act of 1996 (110 Stat.
3213) requires the FAA, when
modifying its regulations in a manner
affecting intrastate aviation in Alaska, to
consider the extent to which Alaska is
not served by transportation modes
other than aviation, and to establish
appropriate regulatory distinctions. In
the NPRM, we requested comments on
whether the proposed rule should apply
differently to intrastate operations in
Alaska. We did not receive any
comments, and we have determined,
based on the administrative record of
this rulemaking, that there is no need to
make any regulatory distinctions
applicable to intrastate aviation in
Alaska.
Environmental Analysis
FAA Order 1050.1E identifies FAA
actions that are categorically excluded
from preparation of an environmental
assessment or environmental impact
statement under the National
Environmental Policy Act in the
absence of extraordinary circumstances.
The FAA has determined this
rulemaking action qualifies for the
categorical exclusion identified in
paragraph 4(j) and involves no
extraordinary circumstances.
Regulations That Significantly Affect
Energy Supply, Distribution, or Use
The FAA has analyzed this final rule
under Executive Order 13211, Actions
Concerning Regulations that
Significantly Affect Energy Supply,
PO 00000
Frm 00016
Fmt 4700
Sfmt 4700
Distribution, or Use (May 18, 2001). We
have determined that it is not a
‘‘significant energy action’’ under the
executive order because while it is a
‘‘significant regulatory action,’’ it is not
likely to have a significant adverse effect
on the supply, distribution, or use of
energy.
Availability of Rulemaking Documents
You can get an electronic copy of
rulemaking documents using the
Internet by—
1. Searching the Federal eRulemaking
Portal (https://www.regulations.gov);
2. Visiting the FAA’s Regulations and
Policies Web page at https://
www.faa.gov/regulations_policies/; or
3. Accessing the Government Printing
Office’s Web page at https://
www.gpoaccess.gov/fr/.
You can also get a copy by sending a
request to the Federal Aviation
Administration, Office of Rulemaking,
ARM–1, 800 Independence Avenue,
SW., Washington, DC 20591, or by
calling (202) 267–9680. Make sure to
identify the amendment number or
docket number of this rulemaking.
Anyone is able to search the
electronic form of all comments
received into any of our dockets by the
name of the individual submitting the
comment (or signing the comment, if
submitted on behalf of an association,
business, labor union, etc.). You may
review DOT’s complete Privacy Act
statement in the Federal Register
published on April 11, 2000 (Volume
65, Number 70; Pages 19477–78) or you
may visit https://DocketsInfo.dot.gov.
Small Business Regulatory Enforcement
Fairness Act
The Small Business Regulatory
Enforcement Fairness Act (SBREFA) of
1996 requires FAA to comply with
small entity requests for information or
advice about compliance with statutes
and regulations within its jurisdiction. If
you are a small entity and you have a
question regarding this document, you
may contact your local FAA official, or
the person listed under the FOR FURTHER
INFORMATION CONTACT heading at the
beginning of the preamble. You can find
out more about SBREFA on the Internet
at https://www.faa.gov/
regulations_policies/rulemaking/
sbre_act/.
Appendix 1—Definition of Terms Used
in This Preamble
For the preamble of this rulemaking, the
following definitions are applicable. These
definitions of terms are for use only with this
rulemaking’s preamble:
a. Advisory ice detection system: An
advisory ice detection system annunciates
E:\FR\FM\03AUR1.SGM
03AUR1
sroberts on DSKD5P82C1PROD with RULES
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
the presence of icing conditions or ice
accretion. The advisory ice detection system
provides information advising the flightcrew
of the presence of ice accretion or icing
conditions. An advisory ice detection system
differs from a primary ice detection system
in that it usually consists of a single ice
detector without redundancies that provide
sufficient reliability to comply with
§ 25.1309. Therefore, it can only be used in
conjunction with other means (most
commonly, visual observation by the
flightcrew) to determine the need for, or
timing of, activating the anti-icing or deicing
system. The flightcrew is responsible for
monitoring the icing conditions or ice
accretion as defined in the AFM (typically
using total air temperature and visible
moisture criteria or visible ice accretion) and
activating the anti-icing or deicing system(s).
b. Airframe icing: Airframe icing is ice
accretions on the airplane, except for the
propulsion system.
c. Anti-icing: Anti-icing is the prevention
of ice accretions on a protected surface,
either:
• By evaporating the impinging water; or
• By allowing it to run back and off the
protected surface or freeze on non-critical
areas.
d. Automatic cycling mode: An automatic
cycling mode is a mode of operation of the
airframe deicing system that provides
repetitive cycles of the system without the
need for the pilot to select each cycle. This
is generally done with a timer, and there may
be more than one timing mode.
e. Deicing: Deicing is the removal or the
process of removal of an ice accretion after
it has formed on a surface.
f. Ice Protection System: An ice protection
system (IPS) is a system that protects certain
critical aircraft parts from ice accretion. To be
an approved system, it must satisfy the
requirements of § 25.1419.
g. Primary ice detection system: A primary
ice detection system is used to determine
when the IPS must be activated. A primary
ice detection system is a system with
redundancies that provide sufficient
reliability to comply with § 25.1309 so the
flight crew does not need to visually monitor
the icing accretions that may be building on
the airplane. The system annunciates the
presence of ice accretion or icing conditions,
and may also provide information to other
aircraft systems. A primary automatic system
automatically activates the anti-icing or
deicing IPS. With a primary manual system,
the flightcrew activates the anti-icing or
deicing IPS upon indication from the primary
ice detection system.
h. Static air temperature: The air
temperature as would be measured by a
temperature sensor not in motion with
respect to that air. This temperature is also
referred to in other documents as ‘‘outside air
temperature,’’ ‘‘true outside temperature,’’ or
‘‘ambient temperature.’’
i. Total air temperature: The temperature
of a parcel of air brought to rest relative to
the aircraft resulting from adiabatic
compression of the parcel. This temperature
is also referred to in other documents as
‘‘stagnation temperature.’’
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements, Safety,
Transportation.
The Amendment
In consideration of the foregoing, the
Federal Aviation Administration
amends Part 25 of Title 14, Code of
Federal Regulations as follows:
■
PART 25—AIRWORTHINESS
STANDARDS, TRANSPORT
CATEGORY AIRPLANES
1. The authority citation for part 25
continues to read as follows:
■
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, and 44704.
2. Amend § 25.143 by revising
paragraph (j) to read as follows:
■
§ 25.143
General.
*
*
*
*
*
(j) For flight in icing conditions before
the ice protection system has been
activated and is performing its intended
function, it must be demonstrated in
flight with the ice accretion defined in
appendix C, part II(e) of this part that:
(1) The airplane is controllable in a
pull-up maneuver up to 1.5 g load
factor; and
(2) There is no pitch control force
reversal during a pushover maneuver
down to 0.5 g load factor.
■ 3. Amend § 25.207 by revising
paragraphs (b) and (h), and adding a
new paragraph (i) to read as follows:
§ 25.207
Stall warning.
*
*
*
*
*
(b) The warning must be furnished
either through the inherent aerodynamic
qualities of the airplane or by a device
that will give clearly distinguishable
indications under expected conditions
of flight. However, a visual stall warning
device that requires the attention of the
crew within the cockpit is not
acceptable by itself. If a warning device
is used, it must provide a warning in
each of the airplane configurations
prescribed in paragraph (a) of this
section at the speed prescribed in
paragraphs (c) and (d) of this section.
Except for showing compliance with the
stall warning margin prescribed in
paragraph (h)(3)(ii) of this section, stall
warning for flight in icing conditions
must be provided by the same means as
stall warning for flight in non-icing
conditions.
*
*
*
*
*
(h) For flight in icing conditions
before the ice protection system has
been activated and is performing its
intended function, with the ice
PO 00000
Frm 00017
Fmt 4700
Sfmt 4700
38339
accretion defined in appendix C, part
II(e) of this part, the stall warning
margin in straight and turning flight
must be sufficient to allow the pilot to
prevent stalling without encountering
any adverse flight characteristics when:
(1) The speed is reduced at rates not
exceeding one knot per second;
(2) The pilot performs the recovery
maneuver in the same way as for flight
in non-icing conditions; and
(3) The recovery maneuver is started
no earlier than:
(i) One second after the onset of stall
warning if stall warning is provided by
the same means as for flight in non-icing
conditions; or
(ii) Three seconds after the onset of
stall warning if stall warning is
provided by a different means than for
flight in non-icing conditions.
(i) In showing compliance with
paragraph (h) of this section, if stall
warning is provided by a different
means in icing conditions than for nonicing conditions, compliance with
§ 25.203 must be shown using the
accretion defined in appendix C, part
II(e) of this part. Compliance with this
requirement must be shown using the
demonstration prescribed by § 25.201,
except that the deceleration rates of
§ 25.201(c)(2) need not be demonstrated.
■ 4. Amend § 25.1419 by adding new
paragraphs (e), (f), (g), and (h) to read as
follows:
§ 25.1419
Ice protection.
*
*
*
*
*
(e) One of the following methods of
icing detection and activation of the
airframe ice protection system must be
provided:
(1) A primary ice detection system
that automatically activates or alerts the
flightcrew to activate the airframe ice
protection system;
(2) A definition of visual cues for
recognition of the first sign of ice
accretion on a specified surface
combined with an advisory ice
detection system that alerts the
flightcrew to activate the airframe ice
protection system; or
(3) Identification of conditions
conducive to airframe icing as defined
by an appropriate static or total air
temperature and visible moisture for use
by the flightcrew to activate the airframe
ice protection system.
(f) Unless the applicant shows that the
airframe ice protection system need not
be operated during specific phases of
flight, the requirements of paragraph (e)
of this section are applicable to all
phases of flight.
(g) After the initial activation of the
airframe ice protection system—
E:\FR\FM\03AUR1.SGM
03AUR1
38340
Federal Register / Vol. 74, No. 147 / Monday, August 3, 2009 / Rules and Regulations
(1) The ice protection system must be
designed to operate continuously;
(2) The airplane must be equipped
with a system that automatically cycles
the ice protection system; or
(3) An ice detection system must be
provided to alert the flightcrew each
time the ice protection system must be
cycled.
(h) Procedures for operation of the ice
protection system, including activation
and deactivation, must be established
and documented in the Airplane Flight
Manual.
■ 5. Amend appendix C to part 25 by
revising part II (e) to read as follows:
Appendix C to Part 25
*
*
*
*
*
Part II—Airframe Ice Accretions for Showing
Compliance With Subpart B
*
*
*
*
*
(e) The ice accretion before the ice
protection system has been activated and is
performing its intended function is the
critical ice accretion formed on the
unprotected and normally protected surfaces
before activation and effective operation of
the ice protection system in continuous
maximum atmospheric icing conditions. This
ice accretion only applies in showing
compliance to §§ 25.143(j) and 25.207(h), and
25.207(i).
Issued in Washington, DC, on July 17,
2009.
Lynne A. Osmus,
Acting Administrator.
[FR Doc. E9–18483 Filed 7–31–09; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2009–0227; Directorate
Identifier 2007–SW–65–AD; Amendment 39–
15978; AD 2009–15–15]
RIN 2120–AA64
Airworthiness Directives; Bell
Helicopter Textron Canada Model 427
Helicopters
AGENCY: Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
We are adopting a new
airworthiness directive (AD) for Bell
Helicopter Textron Canada (BHTC)
Model 427 helicopters. This AD results
from mandatory continuing
airworthiness information (MCAI)
originated by the aviation authority of
Canada to identify and correct an unsafe
condition on an aviation product.
sroberts on DSKD5P82C1PROD with RULES
SUMMARY:
VerDate Nov<24>2008
15:47 Jul 31, 2009
Jkt 217001
Transport Canada, the aviation authority
of Canada, with which we have a
bilateral agreement, states that it has
been determined that the existing
hardware connecting the vertical fin to
the tail rotor gearbox needs to be
upgraded to prevent the vertical fin
from becoming loose.
BHTC has received reports of loose
vertical fins discovered during
inspections. Investigation revealed that
the current vertical fin attachment
hardware may not provide adequate
clamp-up. If not corrected, the vertical
fin could become loose and cause
vibration, which could lead to
subsequent loss of control of the
helicopter. This AD requires actions that
are intended to address this unsafe
condition.
prevent the vertical fin from becoming
loose and causing vibration, which
could lead to subsequent loss of control
of the helicopter. You may obtain
further information by examining the
MCAI and any related service
information in the AD docket.
This AD becomes effective on
September 8, 2009.
ADDRESSES: You may examine the AD
docket on the Internet at https://
regulations.gov or in person at the
Docket Operations office, U.S.
Department of Transportation, M–30,
West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue, SE.,
Washington, DC between 9 a.m. and 5
p.m. Monday through Friday, except
Federal holidays.
You may get the service information
identified in this AD from Bell
Helicopter Textron Canada Limited,
12,800 Rue de l’Avenir, Mirabel, Quebec
J7J1R4, telephone (450) 437–2862 or
(800) 363–8023, fax (450) 433–0272, or
at https://www.bellcustomer.com/files/.
Examining the AD Docket: The AD
docket contains the Notice of proposed
rulemaking (NPRM), the economic
evaluation, any comments received, and
other information. The street address
and operating hours for the Docket
Operations office (telephone (800) 647–
5527) are in the ADDRESSES section of
this AD. Comments will be available in
the AD docket shortly after they are
received.
Bell Helicopter Textron has issued
Alert Service Bulletin No. 427–06–15,
dated December 14, 2006. The actions
described in the MCAI are intended to
correct the same unsafe condition as
that identified in the service
information.
DATES:
FOR FURTHER INFORMATION CONTACT:
Sharon Miles, Aviation Safety Engineer,
FAA, Rotorcraft Directorate, Regulations
and Guidance Group, 2601 Meacham
Blvd., Fort Worth, Texas 76137,
telephone (817) 222–5122, fax (817)
222–5961.
SUPPLEMENTARY INFORMATION:
Discussion
We issued an NPRM to amend 14 CFR
part 39 to include an AD that would
apply to BHTC Model 427 helicopters
on March 4, 2009. That NPRM was
published in the Federal Register on
March 23, 2009 (74 FR 12098). That
NPRM proposed to require actions to
PO 00000
Frm 00018
Fmt 4700
Sfmt 4700
Comments
By publishing the NPRM, we gave the
public an opportunity to participate in
developing this AD. However, we
received no comment on the NPRM or
on our determination of the cost to the
public. Therefore, based on our review
and evaluation of the available data, we
have determined that air safety and the
public interest require adopting the AD
as proposed.
Relevant Service Information
Differences Between This AD and the
MCAI AD
We have reviewed the MCAI AD and
related service information and, in
general, agree with their substance. This
AD differs from the MCAI AD as
follows:
• We do not require compliance ‘‘no
later than November 27, 2007’’, because
that date has passed.
• We refer to the compliance time as
‘‘hours time-in-service’’ rather than ‘‘air
time hours.’’
These differences are highlighted in
the ‘‘Differences Between this AD and
the MCAI AD’’ section in the AD.
Costs of Compliance
We estimate that this AD will affect
about 17 products of U.S. registry. We
also estimate that it will take about 2
work-hours per helicopter to remove
and visually inspect the vertical fin and
the tail rotor gearbox attachment legs
and to re-install the vertical fin. The
average labor rate is $80 per work-hour.
Required parts will cost about $227 per
helicopter. Based on these figures, we
estimate the cost of this AD on U.S.
operators to be $6,579 for the fleet, or
$387 per helicopter, to perform the
inspections and remove and re-install
the vertical fin.
Authority for This Rulemaking
Title 49 of the United States Code
specifies the FAA’s authority to issue
rules on aviation safety. Subtitle I,
section 106, describes the authority of
the FAA Administrator. ‘‘Subtitle VII:
E:\FR\FM\03AUR1.SGM
03AUR1
]]>Agencies
[Federal Register Volume 74, Number 147 (Monday, August 3, 2009)]
[Rules and Regulations]
[Pages 38328-38340]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-18483]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No.: FAA-2007-27654; Amendment No. 25-129]
RIN 2120-AI90
Activation of Ice Protection
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The Federal Aviation Administration amends the airworthiness
standards applicable to transport category airplanes certificated for
flight in icing conditions. The rule requires a means to ensure timely
activation of the airframe ice protection system. This rule is the
result of information gathered from a review of icing accidents and
incidents, and will improve the level of safety for new airplane
designs for operations in icing conditions.
DATES: This amendment becomes effective September 2, 2009.
FOR FURTHER INFORMATION CONTACT: For technical questions concerning
this final rule contact Kathi Ishimaru, FAA, Propulsion and Mechanical
Systems Branch, ANM-112, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Ave., SW., Renton, Washington 98057-
3356; telephone (425) 227-2674; fax: (425) 227-1320, e-mail:
kathi.ishimaru@faa.gov. For legal questions concerning this final rule
contact Douglas Anderson, FAA, Office of Regional Counsel, Federal
Aviation Administration, 1601 Lind Ave., SW., Renton, Washington 98057-
3356; telephone (425) 227-2166; fax: (425) 227-1007, e-mail:
Douglas.Anderson@faa.gov.
SUPPLEMENTARY INFORMATION:
Authority for This Rulemaking
The FAA's authority to issue rules on aviation safety is found in
Title 49 of the United States Code. Subtitle I, Section 106 describes
the authority of the FAA Administrator. Subtitle VII, Aviation
Programs, describes in more detail the scope of the agency's authority.
This rulemaking is promulgated under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, the FAA is charged with promoting
safe flight of civil aircraft in air commerce by prescribing minimum
standards required in the interest of safety for the design and
performance of aircraft. This regulation is within the scope of that
authority because it prescribes new safety standards for the design of
transport category airplanes.
I. Background
On October 31, 1994, an accident involving an Avions de Transport
Regional ATR 72 series airplane occurred in icing conditions.\1\ This
prompted the FAA to initiate a review of aircraft inflight icing safety
and determine changes that could be made to increase the level of
safety. In May 1996, the FAA sponsored the International Conference on
Aircraft Inflight Icing where icing specialists recommended
improvements to increase the level of safety of aircraft operating in
icing conditions. The FAA reviewed the conference recommendations and
developed a comprehensive multi-year icing plan. The FAA Inflight
Aircraft Icing Plan (Icing Plan), dated April 1997,\2\ described
various activities the FAA was contemplating to improve safety when
operating in icing conditions. In accordance with the Icing Plan, the
FAA tasked the Aviation Rulemaking Advisory Committee (ARAC),\3\
through its Ice Protection Harmonization Working Group, to consider the
need for ice detectors or other acceptable means to warn flightcrews of
ice accretion on critical surfaces requiring crew action. This rule
[[Page 38329]]
is based on ARAC's recommendations to the FAA.
---------------------------------------------------------------------------
\1\ This accident and an Empressa Brasilia accident resulted in
NTSB recommendations nos. A-96-56 and A-98-91. This final rule
partially addresses these safety recommendations.
\2\ FAA Inflight Aircraft Icing Plan, dated April 1997,
available in the Docket.
\3\ Published in the Federal Register, December 8, 1997 (62 FR
64621).
---------------------------------------------------------------------------
A. Summary of the NPRM
The notice of proposed rulemaking (NPRM), Notice No. 07-07,
published in the Federal Register on April 26, 2007 (72 FR 20924), is
the basis for this amendment. The comment period closed July 25, 2007.
In the NPRM, we proposed to revise the airworthiness standards for type
certification of transport category airplanes to add requirements to
ensure the timely activation of an airframe ice protection system
(IPS). We also proposed to add requirements to reduce the flightcrew
workload associated with operation of an airframe IPS that is manually
cycled, and to ensure the Airplane Flight Manual includes IPS
procedures for operation.
B. Summary of the Final Rule
The FAA is adopting this final rule because accidents and incidents
occurred where the flightcrew did not operate the airframe IPS in a
timely manner and because of concerns over the flightcrew workload
required to operate an airframe IPS that the flightcrew must manually
cycle when they observe ice accretions. The final rule addresses these
concerns by ensuring that flightcrews are provided with a clear means
to know when to activate the airframe IPS. The final rule reduces the
workload associated with monitoring ice accretions by requiring a
system that operates continuously, a system that automatically cycles
the IPS, or an alert to the flighcrew each time the IPS must be cycled.
This final rule adopts the proposed rule with minor changes and
adds minor conforming changes to rules that were added by the final
rule entitled ``Airplane Performance and Handling Qualities in Icing
Conditions (72 FR 44656, August 8, 2007) (Amendment 25-121).\4\
Amendment 25-121 added specific requirements for airplane performance
and handling qualities for flight in icing conditions. Sections
25.143(j) and 25.207(h), at Amendment 25-121, define requirements that
apply if activating the IPS depends on the pilot seeing a specified ice
accretion on a reference surface (not just the first sign of ice
accretion).
---------------------------------------------------------------------------
\4\ See Docket No. FAA-2005-22840 for complete details.
---------------------------------------------------------------------------
Section 25.1419(e) of this final rule requires one of three methods
of detecting icing and activating the airframe IPS.\5\ Activation based
on the pilot seeing a specified ice accretion on a reference surface
(not just the first sign of ice accretion) is not one of the three
methods allowed under this rulemaking, so any requirements associated
with this method are no longer relevant. Therefore, minor conforming
changes have been made to Sec. Sec. 25.143(j) and 25.207(h) to remove
the references to, and requirements associated with, activating the IPS
in response to the pilot seeing a specified ice accretion on a
reference surface. Additional minor changes have been made to Sec.
25.207(h) to improve readability, including moving a portion of
existing Sec. 25.207(h)(2)(ii) to a new Sec. 25.207(i). The text of
part 25, appendix C, part II(e) has been revised to include a reference
to the new Sec. 25.207(i).
---------------------------------------------------------------------------
\5\ The three methods are: (1) Primary ice detection system, (2)
visual cues of the first sign of ice accretion combined with an
advisory ice detector, and (3) specifying conditions conducive to
airframe icing.
---------------------------------------------------------------------------
In addition, minor changes have been made to Sec. 25.207(b) to
improve clarity and to correct an error introduced by Amendment 25-121.
Section 25.207(b), as amended by Amendment 25-121, states, ``Except for
the stall warning prescribed in paragraph (h)(2)(ii) of this section,
the stall warning for flight in icing conditions prescribed in
paragraph (e) of this section must be provided by the same means as the
stall warning for flight in non-icing conditions.'' However, the stall
warning prescribed by Sec. 25.207(h)(2)(ii) is an exception only to
the Sec. 25.207(b) requirement that stall warning in icing conditions
be provided by the same means as for non-icing conditions. It is not an
exception to, nor is it associated with, the stall warning margin
prescribed by Sec. 25.207(e). The reference to Sec. 25.207(e) is
incorrect and potentially confusing. Therefore, it is removed by this
final rule.
Because of the reformatting of Sec. 25.207(h), as discussed above,
the previous Sec. 25.207(h)(2)(ii) is now Sec. 25.207(h)(3)(ii). The
reference to this paragraph in Sec. 25.207(b) is changed accordingly.
Other minor wording changes have been made to improve clarity. We
consider all of these changes to Sec. 25.207(b) to be technical
clarifications that do not change the intent of this paragraph or
impose an additional burden on applicants.
Below is a more detailed discussion of the rule as it relates to
the comments we received on the NPRM. Appendix 1 defines terms used in
this preamble.
II. Summary of Comments
The FAA received 14 comments concerning the following general areas
of the proposal:
Acceptable methods to determine if the airframe IPS must
be activated.
Automatic cycling of the airframe IPS.
Four of the commenters, the Airline Pilots Association (ALPA),
National Transportation Safety Board (NTSB), BAE Systems Regional
Aircraft, and The Boeing Company (Boeing), expressed support for the
rule. ALPA supported the rule without recommendations to revise the
rule. Twelve commenters suggested specific improvements or
clarifications. They were the NTSB, BAE Systems Regional Aircraft,
Boeing, the Air Crash Victims Families Group, Bombardier Aerospace,
Marinvent Corporation, the Regional Airline Association, Swan
International Sensors, Transport Canada, and three individuals.
Ameriflight LLC (Ameriflight) opposed certain provisions of the rule.
Summaries of the comments and our responses (including explanations of
any changes to the final rule in response to the comments) are provided
below.\6\
---------------------------------------------------------------------------
\6\ The full text of each commenter's submission is available in
the Docket.
---------------------------------------------------------------------------
A. Ice Detection, Activation of Airframe IPS, and Automatic Cycling of
Airframe IPS
In the NPRM, we proposed one of the following three methods for ice
detection and activation of the airframe IPS to ensure timely
activation of the airframe IPS (proposed Sec. 25.1419(e)):
A primary ice detection system that automatically
activates or alerts the flightcrew to activate the airframe IPS;
Visual cues for recognition of the first sign of ice
accretion combined with an advisory ice detection system that alerts
the flightcrew to activate the airframe IPS; or
Identification of conditions conducive to airframe icing
for use by the flightcrew to activate the airframe IPS when those
conditions exist.
In addition, proposed Sec. 25.1419(g) would require an airframe
IPS that operates cyclically (for example, deicing boots) to
automatically cycle after the initial activation, or installation of an
ice detection system to alert the flightcrew each time the deicing
boots must be activated.
The following comments were received on these proposals.
1. Oppose Installation of an Ice Detection System
Ameriflight opposed the installation of an ice detection system
because properly trained flightcrews can easily detect ice accretion by
means such as ice forming in the corners of the
[[Page 38330]]
windshield or on windshield wiper arms. An individual commenter
believed nothing, including an ice detector, can replace pilots looking
out the window to gather information on icing.
Ameriflight also suggested that it would be difficult or impossible
to design a sufficiently reliable ice detection system that would be
economically feasible and a practicable substitute for flightcrew
training and vigilance. The individual commenter opposed installation
of an ice detection system because of his experience on a military
airplane that was equipped with an unreliable icing warning light.
The FAA agrees that flightcrew training and vigilance are extremely
important to ensure the safe operation of aircraft in icing conditions.
However, visual observation of ice accretion alone, as suggested by
Ameriflight and the individual commenter, is not sufficient to ensure
timely operation of the airframe IPS. The flightcrew's observation of
ice accretions can be difficult during times of high workload,
nighttime operations, or when clear ice has accumulated. In addition,
there have been icing accidents and incidents where the flightcrew was
either completely unaware of ice accretion on the airframe, or was
aware of ice accretion but judged that it was not significant enough to
warrant operation of the airframe IPS. Therefore, reliance on only
flightcrew visual observation of ice accretion alone is not adequate
and must be supplemented with an advisory ice detection system to
provide an acceptable level of safety.
The FAA acknowledges that it is not a simple task to design and
certificate an ice detection system. However, ice detection systems
exist today that meet the reliability requirements of part 25. Section
25.1309 ensures the degree of reliability of an airframe IPS is
commensurate with the hazard level associated with the failure of the
airframe IPS.
In response to the contention that an ice detector would not be
economically feasible, the FAA notes that on recent part 25 airplane
certifications manufacturers sought and received approval for
installation of ice detectors without an FAA requirement for such a
system. Therefore, the FAA infers that these manufacturers consider the
installation of ice detectors economically feasible.
2. Reliability of Advisory Ice Detection System
Transport Canada suggested that the reliability level of the
advisory ice detection system should be on the order of 1 x 10\-5\
failure per flight hour. Transport Canada indicated the classification
assigned to the unannunciated loss of an advisory ice detection system
would appear to depend upon the advisory ice detection system design,
the IPS design, and the airplane on which it is installed. Therefore,
it is Transport Canada's position that specific cases may need to
consider the unannunciated loss of the advisory ice detection system as
a major failure. The natural tendency of flightcrews to become
accustomed to using the advisory ice detection system may increase the
need to make flightcrews aware of failure of the advisory ice detection
system. The flightcrews may need to take extra precautions when they
have detected a possible failure of the advisory ice detection system.
The FAA infers that Transport Canada would like the proposed rule
changed to include a minimum reliability requirement for the advisory
ice detection system. The FAA finds it is unnecessary to revise this
rule to include a minimum reliability requirement for the advisory ice
detection system because Sec. 25.1309 requires the determination of
the hazard level associated with failure of any airplane system which
then drives the required degree of reliability of that system.
Additionally it would not be appropriate to pick a specific minimum
reliability requirement for the advisory ice detection system because,
as pointed out by the commenter, the hazard level associated with the
unannunciated loss of the advisory ice detection system may depend upon
the advisory ice detection system design, the airframe IPS design, and
the airplane on which it is installed. However, the FAA may consider
including guidance on advisory ice detection system reliability in the
associated advisory circular.
3. Do Not Activate Pneumatic Deicing Boots at First Sign of Ice
Accretion
Ameriflight did not support activation of pneumatic deicing boots
at the first sign of ice accretion, noting that these boots work better
and continue to shed ice more effectively for a longer period if
airfoil leading-edge ice is allowed to build to a sufficient thickness
before cycling the boots. The commenter stated that when the boots are
operated at the first indication of ice, the ice is only partially
shed. The ice remaining on the boot provides a rough surface on which
additional ice accumulates more readily than on a smooth boot surface,
shortening the duration of the boots' ability to clean the wing
effectively.\7\ Thus, the commenter believed that activating the boots
at the first sign of ice was actually contrary to safety and
Ameriflight's long experience with this system.
---------------------------------------------------------------------------
\7\ The commenter noted that this is particularly true of older
boots that have been on the wing for several seasons and which--
although completely airworthy--have leading edges which have become
somewhat roughened by the impacts of ice crystals, snow, hail, etc.,
and provide a better ``tooth'' to which structural ice can adhere.
---------------------------------------------------------------------------
The FAA has issued airworthiness directives requiring activation of
pneumatic deicing boots early and often. The airworthiness directives
and this rule address icing accidents and incidents where the
flightcrew was either completely unaware of ice accretion on the
airframe, or was aware of ice accretion but judged that it was not
significant enough to warrant operation of the airframe IPS.
The commenter raised concerns over residual ice, which is ice
remaining (not shed) after a complete boot cycle. The FAA participated
in high and low speed icing wind tunnel tests that contradict the
commenter's position that boots work better, and continue to shed ice
effectively, for a longer period if airfoil leading ice is allowed to
build before cycling the boots.
The higher speed icing wind tunnel tests (>=180 KCAS) showed that
ice was shed after each boot activation and that after 2 or 3 cycles
there was no discernible difference between ice accretions from early
versus delayed activation of the boots. The residual ice that remained
on the boot after cycling at the first sign of ice accretion was always
smaller than the amount of ice that was present on the boot during the
time that it took for \1/4\-inch of ice to form.
The lower speed icing wind tunnel tests (<=144 KCAS) showed large
amounts of residual ice which the boots had difficulty shedding,
regardless of the activation method employed. Immediate activation of
an automatic system did not degrade ice shedding performance. Cycling
early and often resulted in shedding sooner than waiting for a
specified ice accretion thickness. For example, simulating an automatic
one minute system activated at first sign of icing at 14 [deg]F, 108
KCAS, resulted in a ``good shed'' at the 15th cycle at 15 minutes.
Waiting for a \1/4\ inch accretion before cycling resulted in a ``good
shed'' at the 12th cycle at 20 minutes. The residual ice after ``good
sheds'' was similar regardless of the boot activation method. Based on
the results of these tests, we do not agree with Ameriflight's position
about the
[[Page 38331]]
effectiveness of pneumatic deicing boots.
4. Oppose Automatic Activation and Cycling of Airframe IPS
Ameriflight also opposed any system that would automatically
activate ice protection equipment or automatically cycle pneumatic
deicing boots. Ameriflight suggested automatic activation of deicing
boots during low speed operation, takeoff, or in the landing flare
could cause handling quality problems on some aircraft. The commenter
stated that although such automatic operation could be inhibited by
airspeed, landing gear position, or other sensors, these in turn add
increments of complexity and potential unreliability that tend to
offset the automatic systems' safety value.
The FAA agrees that automatic activation of the deicing boots
during some phases of flight (for example, landing flare) could result
in handling quality problems on some airplanes. As Ameriflight pointed
out, inhibiting automatic activation during these phases of flight to
prevent any handling quality problems adds complexity to the system and
could potentially increase the chances for the system not to activate
when it is needed. However, the FAA finds that the increase in safety
afforded by automatic activation of the airframe IPS outweighs the
concerns expressed by Ameriflight and that compliance with other
regulations would mitigate those concerns.
Section 25.143(a) requires airplanes to be safely controllable and
maneuverable during takeoff, climb, level flight, descent, and landing.
Section 25.143(b) states that it must be possible to make a smooth
transition from one flight condition to another without exceptional
piloting skill, alertness, or strength under any probable operating
condition. If the airplane cannot operate safely with the airframe IPS
activated during a particular phase of flight, automatic activation of
the airframe IPS would need to be inhibited during that phase of
flight.
Any potential effect on the reliability of the system to activate
would be assessed in accordance with Sec. 25.1309, which requires that
systems must be designed to perform their intended function under any
foreseeable operating condition. Section 25.1309 also establishes the
minimum allowable system reliability, which is based on the hazard that
would result from failure of the system. Therefore, the increase in
safety afforded by automatic activation of the airframe IPS would not
be offset by the increase in complexity and potential effect on
reliability if automatic activation must be inhibited in certain flight
phases.
Ameriflight commented that IPS other than deicing boots should be
controlled by active involvement of the flightcrew, rather than
automatically. IPS operation at inopportune times could actually
decrease safety, for example by causing (i) preexisting ice
accumulations to be shed into engine inlets, (ii) undesired drawdown of
engine bleed air, or (iii) an excess electrical load. Systems could be
designed with sensors to protect against such inopportune operation,
but only at the price of additional complexity and unreliability.
Ameriflight opposed any system that would automatically activate ice
protection equipment or automatically recycle pneumatic deicing boots
because automatic systems may fail, and the flightcrew might be unaware
the IPS is not operating. ``Automatic'' systems add complexity, testing
requirements, and systems interfaces, and often result in decreased
overall reliability and tend to remove the flightcrew from the
operational loop.
The final rule does not require automatic activation of airframe
IPS, but does allow it if a primary ice detection system is installed.
If an applicant chooses to certificate a system to activate the
airframe IPS automatically, compliance with part 25 regulations ensure
the airplane can operate safely any time the airframe IPS is operated.
Issues raised by the commenter such as ice shedding, bleed air, and
electrical power are considered during airplane certification. As
previously mentioned, any system that would be necessary to inhibit
automatic activation would be required to comply with Sec. 25.1309,
which ensures system reliability commensurate with the hazard
associated with the failure of that system. As indicated by the
commenter, an automatic system may fail. However, Sec. 25.1309
requires assessing the hazard associated with the failure and providing
appropriate warnings commensurate with the hazard. Compliance with part
25 ensures the safe operation of the airplane if the airframe IPS is
automatically activated regardless of whether the airframe IPS is a
thermal anti-ice system or a deicing boot system.
5. Necessity for Visual Cues in Combination With an Advisory Ice
Detector
Bombardier noted the requirement for an advisory system, in
combination with visual cues for recognition of ice accretion, implies
that visual cues are necessary because of ice detector failure and not
ice detector performance. The fact that no visual cues are necessary
for a primary ice detection system (dual ice detectors) seems to
indicate an intent to focus on ice detection failure. Therefore, the
commenter believed that it would be appropriate to address how primary
ice detectors should be certified knowing these potential limitations.
The FAA reviewed our airworthiness directives that require
operating deicing boots at the first sign of ice accretion. We
determined that this means of IPS operation should be improved because
such observations can be difficult during times of high workload,
nighttime operations, or when clear ice has accumulated. Therefore, to
mitigate the effects of human sensory limitations and inadequate
attention due to workload, the final rule requires visual cues of ice
accretions in combination with an advisory ice detector. The
combination of visual cues and advisory ice detectors is intended to
address the potential limitations of human beings, not of the ice
detectors, as suggested by the commenter. Limitations of primary ice
detectors, as well as advisory ice detectors, are addressed during
certification through the requirements of Sec. Sec. 25.1301 and
25.1309. These regulations require that equipment function properly
when installed, perform its intended functions under any foreseeable
operation condition, and ensure system reliability commensurate with
the hazard associated with a failure of that system.
6. Require Automatic Activation of Airframe IPS
An individual commenter requested that Sec. 25.1419(e) be revised
to allow only automatic activation of airframe IPS in appendix C icing
conditions, and to require IPS status displays. The commenter suggested
that all other proposed options to ensure timely activation of the
airframe IPS be deleted. The commenter believed that visual cues are
not adequate, there is no correlation between the ice formed on the
airframe and the thickness of the ice formed on the ice detector, and
automatic activation would minimize hazards by making flightcrews aware
of icing conditions early.
The FAA disagrees and maintains that the proposed standard that
allows several means to ensure timely activation of the airframe ice
protection equipment is acceptable. Icing accidents and incidents do
not support the suggested revision. The FAA acknowledges that automatic
activation of airframe IPS based on icing conditions will likely result
in earlier activation and minimize the effects of icing compared to
waiting until ice accretions have formed on the airframe.
[[Page 38332]]
However, later activation is acceptable, provided an applicant
substantiates the airplane can operate safely with the ice accretion
present at the time the airframe IPS is activated and becomes
effective. Consequently, if the airframe IPS is activated based on an
ice detector, it is the ice accretion present on the airframe that is
important, not the correlation between the ice shape on the ice
detector and the airframe. The commenter pointed out icing accidents
and incidents where the flightcrew was unaware of ice accretions and
concluded that visual cues are inadequate. The FAA concurs that visual
cues alone are not adequate, but visual cues in addition to an advisory
ice detection system would provide an acceptable level of safety and
mitigate the effects of human sensory limitations and inadequate
attention due to workload.
7. Remove Option To Activate Airframe IPS Based on Temperature and
Visible Moisture
Proposed Sec. 25.1419(e)(3) would allow activation of the airframe
IPS based on conditions conducive to airframe icing as defined by
appropriate static or total air temperature and visible moisture. Three
commenters, Transport Canada, Swan International Sensors, and an
individual commenter did not consider proposed Sec. 25.1419(e)(3) an
acceptable alternative to requiring an ice detection system. Transport
Canada noted that it is common to base temperature indication on a
single sensor, which may not have the required reliability and failure
monitoring. Moreover, the display of temperature may not be conspicuous
particularly on electronic flight instrument systems. In addition, it
may not be easy to see visible moisture at night. The commenter
requested that if paragraph (e)(3) is retained, it should be limited to
airplanes that are at a lower risk of icing related incidents and
accidents. The individual commenter stated that training flightcrews to
recognize conditions conducive to icing is not an adequate solution
because such training and documentation have existed for some time, yet
icing related accidents still occurred.
The FAA concludes that Sec. 25.1419(e)(3) should be retained as
proposed because activation of the airframe IPS using visible moisture
and temperature is based on the methodology currently being used safely
for activating engine IPS. Flightcrews are trained to recognize
conditions conducive to icing (that is, visible moisture and
temperature) and have used this method safely for the operation of
engine IPS. While there may be some challenges to observing visible
moisture at night, the challenge is no different than for engine IPS
activation. The FAA expects that activation of the airframe IPS using
the same type of cues will result in timely activation just as it has
for engines.
Furthermore, the accident and incident history does not support the
commenter's position that training flightcrews to recognize conditions
conducive to icing has not been successful. For airplanes with an
airframe IPS that is activated based on visible moisture and
temperature, the FAA is unaware of accidents or incidents attributed to
the flightcrew not activating the airframe IPS.
Regarding the concern over the reliability of the current equipment
used to detect temperature, the equipment must meet the requirements of
Sec. 25.1309. This could result in the need to install different
temperature sensing equipment than what is used on aircraft today.
8. Allow Temperature and Visible Moisture in Combination With an
Advisory Ice Detection System
Transport Canada recommended the FAA include temperature and
visible moisture in combination with an advisory ice detection system
as an acceptable configuration under the proposed rule.
The FAA determines there is no need to revise the rule to
explicitly provide the suggested option. The regulations provide
minimum requirements and an applicant has the option of exceeding these
requirements. Therefore, even though the suggested option is not
identified in the proposed rule, it would be acceptable for an
applicant to comply with proposed Sec. 25.1419(e)(3) and voluntarily
go beyond that requirement and install an advisory ice detection
system.
9. Need Definition of Environmental Conditions Conducive to Icing
The National Transportation Safety Board (NTSB) commented that
industry could not realistically be expected to implement Sec.
25.1419(e)(3) until the FAA provides a more specific definition of
``environmental conditions conducive to icing.'' Swan International
Sensors stated that the flightcrew would be required to interpret icing
conditions because they are not defined adequately by paragraph (e)(3).
The FAA concludes that the proposed rule adequately defined
environmental conditions conducive to icing and does not require
interpretation by the flightcrew. The rule requires the manufacturer to
identify conditions conducive to airframe icing as defined by an
appropriate static or total air temperature and visible moisture for
use by the flightcrew to activate the airframe IPS. The proposed rule
defined the environmental conditions as a static or total air
temperature and visible moisture. Advisory circular (AC) 25-1419-2,
Compliance with the Ice Protection Requirements of Sec. Sec.
25.1419(e), (f), (g), will provide guidance on determining the
temperature cue. Therefore, we made no changes to proposed Sec.
25.1419(e)(3) in this final rule.
10. Require Aircraft Be Equipped With All Three Proposed Methods of
Airframe Ice Detection
The proposed Sec. 25.1419(e) would require one of three ice
detection and activation methods. The Air Crash Victims Families Group
and an individual commenter requested that the final rule require all
three ice detection and activation methods identified in proposed Sec.
25.1419(e). The commenters also requested that the FAA require
automatic ice detection systems to warn pilots of icing and to activate
IPS automatically. The commenters referenced the Circuit City airplane
accident in Pueblo, Colorado, on February 16, 2005, where the NTSB
found the probable cause to be the flightcrew's failure to monitor and
maintain airspeed and comply with procedures for ice boot activation on
approach.\8\ In addition, the NTSB found that distractions impeded the
flightcrew's ability to monitor and maintain airspeed and manage the
deicing system.
---------------------------------------------------------------------------
\8\ The commenter noted that the Cessna Citation 560 was
equipped with deice boots that do not cycle automatically, which
require pilots to continually monitor accumulation and reactivate
the deice boots each time.
---------------------------------------------------------------------------
The FAA finds that icing accidents and incidents do not support the
commenters' suggestion to require all three proposed methods to ensure
timely activation of the airframe IPS or require a system to activate
the airframe IPS automatically. The three proposed methods would
independently ensure timely activation of the airframe IPS. The FAA is
unaware of any icing accidents or incidents attributed to untimely
activation of the airframe IPS on an airplane that had equipment
compliant with this rule. The flightcrew of the Circuit City airplane
relied on visual observation of ice accretions for determining if the
airframe IPS should be activated and cycled manually. There was not a
detector to tell the flightcrew to cycle the airframe IPS. This rule
requires an advisory ice detection
[[Page 38333]]
system in addition to visual observation of the first sign of ice
accretion as a means to determine the airframe IPS must be activated.
In addition, the rule addresses flightcrew workload by requiring deice
boots to automatically cycle or by equipping the airplane with an ice
detection system to alert the flightcrew each time the airframe IPS
must be cycled. For these reasons, the suggested revisions are not
being adopted.
11. Require Manual Back-Up to Automatic Activation of Airframe IPS
Proposed Sec. 25.1419(g) addressed the flightcrew workload
associated with an airframe IPS that operates cyclically and that
requires continuous monitoring of ice accretions to determine when to
activate the IPS. Proposed paragraph (g)(2) requires that these systems
automatically cycle the airframe IPS to eliminate the need to
continuously monitor ice accretions. An individual commenter requested
that proposed paragraph (g) be revised to require manual system
activation as a back-up to automatic activation. Compliance with Sec.
25.1309, which requires an assessment of the hazard associated with the
failure of a system, will determine whether a manual system is required
as a back-up to an automatic activation system. Therefore, the FAA
finds it is unnecessary to require a back-up manual system as suggested
by the commenter.
12. Allow an Aerodynamic Performance Monitoring System
Marinvent and the Regional Airline Association requested revising
the proposed rule to include an aerodynamic performance monitoring
(APM) system as an alternative to ice detection systems.\9\ The
commenters believed APMs have several advantages over ice detectors,
but that they do not inherently detect ice. Therefore, the proposed
rule text did not directly address APMs because they are not strictly
``ice detection systems.'' The commenters understood that applicants
may propose the APM as an alternative means of compliance by
demonstrating an equivalent level of safety. However, the commenters
thought the process of obtaining an equivalent level of safety finding
would discourage the use of this alternative and believed there was a
fundamental conceptual difference between the ice detection and
aerodynamic monitoring, making it difficult for the applicant and the
regulator to establish common ground to demonstrate an equivalent level
of safety. The commenters contended the existing proposed rule text
would effectively exclude the APM systems as a viable alternative means
of compliance with the regulation.
---------------------------------------------------------------------------
\9\ Aerodynamic performance monitoring systems directly measure
the degradation of airfoil performance caused by the roughness and
profile changes induced by the contamination of the airfoil.
---------------------------------------------------------------------------
The Regional Airline Association added that at least one of their
associate members currently provides an APM system as an option in
their aircraft (Aerospatiale model ATR 72) for their airline members.
The FAA concludes that, at this time, APMs are not sufficiently
mature to use as a method to ensure timely activation of the airframe
IPS. Further, contrary to the commenters' beliefs, the equivalent level
of safety process is commonly used in certification programs and would
not discourage the use of alternatives such as an APM.
In response to the Regional Airline Association's comment that an
APM is currently offered as an option on the Aerospatiale ATR 72
aircraft, the FAA is aware that Aerospatiale has certificated an
aircraft performance monitor, not an aerodynamic performance monitor.
The aircraft performance monitor system used on the ATR 72 is intended
to provide the flightcrew with information that could help them manage
a severe icing encounter. The ATR 72's aircraft performance monitor
system is not intended, nor certificated, to provide the flightcrew
with information to ensure the airframe IPS is activated in a timely
manner.
B. Airframe Ice Protection System Operation
Proposed Sec. 25.1419(f) would allow an applicant to substantiate
that the airframe IPS need not be operated during specific phases of
flight. An individual commenter requested that Sec. 25.1419(f) be
revised to allow airplane operations with the IPS inactive if the
airplane can be operated safely with the ice accretions associated with
probable failures. The commenter also requested that Sec. 25.1419(f)
be revised to require that safe operation be demonstrated by flight
test, icing tunnel tests, or other means.
The FAA finds the suggestion to consider only the ice accretions
associated with probable failures unacceptable. Compliance with Sec.
25.1309 determines the failures that must be considered, and this rule
should not predetermine that only probable failures need be considered.
Regarding the suggestion to specify the acceptable means of showing
compliance, the FAA finds it is not necessary because Sec. 25.1419(a)
and (b) already specify the means that can be used to substantiate that
an airplane can operate safely in icing conditions. For these reasons,
the FAA did not adopt the suggested changes to Sec. 25.1419(f).
C. Airplane Flight Manual Requirements
Proposed section Sec. 25.1419(h) would require that procedures for
operation of the IPS be established and documented in the Airplane
Flight Manual (AFM).
BAE Systems Regional Aircraft requested the word ``airframe'' be
added to Sec. 25.1419(h). The FAA finds that adding the word
``airframe'' to Sec. 25.1419(h) is not necessary because the
procedures for operation of both engine and airframe IPS must be in the
AFM. Traditionally, manufacturers provide adequate information in the
AFM regarding the operation of the engine IPS, but information for an
airframe IPS is sometimes lacking or is not consistent with the methods
of operation used during certification. Proposed paragraph (h) is
included to ensure future AFMs also include information for the
operation of airframe IPS.
Another commenter requested that Sec. 25.1419(h) be deleted
because the requirement is already covered by the existing regulation
in the section titled ``Airplane Flight Manual.''
The FAA finds that the sections relating to the AFM in part 25,
Subpart G (Sec. Sec. 25.1581-25.1587) do not explicitly address IPS
operations. Therefore, the Subpart G regulations must be supplemented
with the proposed Sec. 25.1419(h) to ensure that procedures for
operating the IPS are included in the AFM and are consistent with the
requirements of Sec. 25.1419. For these reasons, the suggested
revision is not being adopted in this final rule.
Boeing requested that proposed Sec. 25.1419(g)(1) be changed to
require that the IPS must operate continuously only while the aircraft
remains in icing conditions. The proposed rule would require operating
the anti-icing system continuously throughout a potentially long flight
after exiting icing conditions. Such continued operation while not in
icing conditions is not necessary and wastes fuel. Boeing suggested
that the proposed rule be revised to specify when an IPS that operated
continuously can be deactivated.
Based on Boeing's comment, it appears the intent of Sec.
25.1419(g) may be unclear. Proposed Sec. 25.1419(g) provided three
options to minimize the flightcrew workload associated with airframe
IPS operation. One option (Sec. 25.1419(g)(1)) is an airframe IPS that
operates continuously. Section 25.1419(g)(1) has been revised to
clarify
[[Page 38334]]
that the airframe IPS must be designed to operate continuously, not to
require continuous operation of an airframe IPS. We also clarified that
procedures for operation of the IPS as specified in Sec. 25.1419(h)
include both activation and deactivation procedures. In addition, we
revised Sec. 25.1419(g)(1) to say that the IPS must be designed to
operate continuously.
For future certification programs (as with past certification
programs), it is incumbent upon the manufacturer to propose and
substantiate when it is acceptable to deactivate the IPS. The only
difference from past certifications will be that the activation
requirements of Sec. 25.1419(e) must be considered.
D. Other Comments
1. Clarify the Rule Is Applicable to Airframe IPS
BAE Systems Regional Aircraft requested that Sec. 25.1419(f) and
(g) be modified to indicate the ``airframe'' IPS are being referenced.
The FAA agrees that Sec. Sec. 25.1419(f) and (g) should be
clarified by adding the word ``airframe.'' Therefore, in Sec.
25.1419(f), we revised the introductory language to reference the
airframe IPS (``Unless the applicant shows that the airframe ice
protection system * * *). In Sec. 25.1419(g), we made a similar
revision to the introductory language (``After the initial activation
of the airframe ice protection system * * *).
2. Expand Rule To Include Certain Existing Airplanes and Prohibitions
With IPS Inoperable
The NTSB requested a revision to address its perceived ongoing
disconnect between the industry's guidance on deicing boot activation
and what the FAA has learned and research has shown regarding ice
bridging and deice boot effectiveness. The NTSB noted the Cessna 208
Caravan AFM instructs crews to wait for \1/4\ to \3/4\ inch of ice to
accrete before activating the pneumatic deicing boots.
The FAA finds that for the new part 25 airplane and for existing
part 25 airplanes that are modified in the future with significant
airframe IPS design changes, this rule precludes the potential for
perpetuating the belief that flightcrews should wait for a specific
amount of ice to accumulate before activating the deicing boots. The
final rule requires activation of the airframe IPS based on ice
detectors or icing conditions and requires procedures for operating the
IPS in the AFM. Therefore, for new part 25 airplanes, the industry
guidance in the AFM will reflect the FAA regulatory requirements for
activation of the IPS which does not allow activation of deicing boots
based on the flightcrew determining that a specified thickness of ice
has accumulated.
The NTSB, Air Crash Victims Families Group, and one other commenter
requested the proposed rule be expanded to include existing airplanes
equipped with pneumatic deicing boots and reference the NTSB safety
recommendations A-98-91, A-98-100, A-07-14, and A-07-16 (which
recommend icing related actions the FAA should take for existing
airplanes).
We disagree. The NPRM did not address this issue, and revising this
final rule to include retrofit requirements for existing airplanes
would delay its issuance, which is not in the interest of safety.
However, the FAA may consider additional rulemaking to address
activation of the IPS on part 121 airplanes at a later date.
The NTSB also believed the proposed rule should prohibit crews from
operating the airplane when certain functions of the IPS are
inoperable, and should prohibit flight into known icing conditions if
certain functions of the IPS are inoperable.
The FAA maintains that if certain equipment is inoperable,
transport category airplanes should be prohibited from flight in
forecasted icing conditions in addition to prohibiting flight in known
icing conditions (as suggested by the NTSB). However, we do not concur
with incorporating such a requirement into a certification rule. The
FAA utilizes the Master Minimum Equipment List (MMEL) to evaluate
whether an airplane may be operated with a particular piece of
equipment inoperative. Each airplane is unique and the MMEL is the best
way to determine the impact of an inoperable piece of equipment.
3. Revise Rule To Encourage Specific Airfoil Designs
The Regional Airline Association noted that several aircraft types
over many years have been operated safely without any incidents or
accidents attributed to icing. The commenter requested the proposed
rule be rewritten to encourage airfoil design as the best means to
address safety concerns due to operations in icing conditions.
Although the FAA does not write regulations to ``encourage''
specific airfoil designs, we do establish the performance and handling
requirements an airplane must meet to substantiate that the airplane
can operate safely in icing conditions. These safety requirements (to a
certain extent) drive the design of the airfoil. However, it is the
responsibility of the airframe manufacturer to design an airplane that
meets the Federal Aviation Regulations icing regulations.
E. Economic Analysis
An individual commenter stated that the Goodrich Corporation cost
estimates identified in the NPRM appear to be realistic, but the non-
recurring costs could be reduced by a system that uses a detector that
is different than the assumed ice detector. The commenter suggested
using a ``universal'' sensor or detector that is independent of the
airplane type and installation location; like a pressure sensor, a
temperature sensor, a humidity sensor, or a system that consists of
sensors that are universal.\10\
---------------------------------------------------------------------------
\10\ The commenter estimated the non-recurring costs could be:
Architecture/integration $7,500, qualification testing $10,000,
system certification $50,000, and installation design $5,000.
---------------------------------------------------------------------------
The commenter provided cost estimates that are less than the ice
detector certification estimates used in our economic assessment.
However, even with the more costly estimates, the FAA concluded the
economic impact of the rulemaking is minimal. Since decreasing the cost
estimates would not affect this conclusion, the FAA has determined it
is not necessary to revise the costs in our economic assessment.
The FAA requested comments from U.S. manufacturers on their plans
to produce a new part 25 certificated aircraft with deicing systems
that operate cyclically and the associated certification costs.
Bombardier and Transport Canada referenced this FAA request, but did
not provide any data. Bombardier believes the FAA's economic analysis,
which noted the trend of part 25 manufacturers to install thermal anti-
ice protection systems in newly certificated part 25 airplanes, implied
that the FAA considered ``cyclical'' deicing systems to be
anachronistic. Bombardier indicated that technology in development may
reintroduce cyclical deicing systems. Transport Canada indicated that
if cyclical deicing systems are being considered for the future, then
the FAA trend noted in the NPRM would not be correct.
While technology development may result in the reintroduction of
cyclical deicing systems in the future, the FAA is unaware of any
actual plans to produce a new part 25 certificated aircraft with
deicing systems that operate cyclically and the associated
certification costs. Without such information, we believe the economic
assessment stating that the trend for
[[Page 38335]]
new part 25 aircraft certifications is toward thermal anti-ice ice
protection systems is accurate.
Paperwork Reduction Act
The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires
that the FAA consider the impact of paperwork and other information
collection burdens imposed on the public. We have determined that there
is no current or new requirement for information collection associated
with this amendment.
International Compatibility
In keeping with U.S. obligations under the Convention on
International Civil Aviation, it is FAA policy to comply with
International Civil Aviation Organization (ICAO) Standards and
Recommended Practices to the maximum extent practicable. The FAA has
determined that there are no ICAO Standards and Recommended Practices
that correspond to these regulations.
III. Regulatory Evaluation, Regulatory Flexibility Determination,
International Trade Impact Assessment, and Unfunded Mandates Assessment
Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 directs that each Federal agency
shall propose or adopt a regulation only upon a reasoned determination
that the benefits of the intended regulation justify its costs. Second,
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires
agencies to analyze the economic impact of regulatory changes on small
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits
agencies from setting standards that create unnecessary obstacles to
the foreign commerce of the United States. In developing U.S.
standards, this Trade Act requires agencies to consider international
standards and, where appropriate, that they be the basis of U.S.
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L.
104-4) requires agencies to prepare a written assessment of the costs,
benefits, and other effects of proposed or final rules that include a
Federal mandate likely to result in the expenditure by State, local, or
Tribal governments, in the aggregate, or by the private sector, of $100
million or more annually (adjusted for inflation with base year of
1995). This portion of the preamble summarizes the FAA's analysis of
the economic impacts of this final rule.
An assessment has been conducted of the economic cost impact of the
final rule amending Sec. 25.1419 of Title 14 of the Code of Federal
Regulations (14 CFR) part 25, and we have determined the final rule has
minimal costs. This final rule is the result of information gathered
from a review of historical icing accidents and incidents. It is
intended to improve the level of safety when part 25 airplanes are
operated in icing conditions.
Amendment 25-121 revised Sec. 25.207 to add requirements for
considering the effects of icing on stall warning. At the time we
issued Amendment 25-121, it was permissible for type certificate
applicants to instruct pilots to wait for a specified amount of ice
accretion to accumulate before activating the ice protection system
(IPS). Section 25.207(h)(1), as adopted in Amendment 25-121, addressed
this scenario by requiring flight testing with the specified amount of
ice accretion to show the airplane could be operated safely until the
IPS is functioning. This rule will prohibit use of this method for
activating the IPS. Therefore, there is no longer any need to have the
existing provision Sec. 25.207(h)(1) that provides stall warning
margin requirements for this method, and we are removing those
provisions from Sec. 25.207. This is a conforming change, and does not
add any new requirements or costs. In addition, Sec. 25.207 has been
revised to improve its readability and to correct an error introduced
by Amendment 25-121, but none of these revisions affect the substantive
requirements.
This final rule requires newly certificated part 25 transport
category airplanes certificated for flight in icing conditions to have
one of the following methods to detect ice and activate the airframe
IPS:
A primary ice detection system, automatic or manual;
The definition of visual cues for recognition of ice
accretion on a specified surface combined with an advisory ice
detection system that alerts the flightcrew; or
The identification of icing conditions by an appropriate
static or total air temperature and visible moisture cues.
The FAA did not receive comments causing us to change our NPRM
determination that the expected costs are minimal. Bombardier indicated
future technology may reintroduce cyclical deicing systems. Since 1971,
no U.S. manufacturer has certificated cyclical deicing systems. Also,
recent part 23 Very Light Jet (VLJ) certification programs have
automatic cyclical deicing systems. We do not anticipate manufacturers
to certificate manually-cycled deicing systems.
A. Cost Discussion
1. Major Assumptions
This evaluation makes the following assumptions:
We used a $50 hourly rate for a mechanic/technician and a
$75 hourly rate for an engineer working for an airplane manufacturer or
modifier.
Whenever various compliance options are available to the
manufacturers, we chose the least costly option in our analysis.
Other data and derived assumptions are discussed in the following
sections on costs and benefits.
2. Estimate of Costs
This section discusses the costs of a new requirement for transport
category airplane manufacturers to include a method of ice detection on
newly certificated airplanes. The cost estimate included below is not
an estimate per manufacturer, rather an estimate per new part 25
airplane certification.
This final rule will require manufacturers of part 25 airplanes to
provide the flightcrew with an effective method of ice detection. Such
a method can provide a means, using an ice detection system (IDS), to
alert the flightcrew of icing conditions and enable timely activation
of the airframe IPS for the initial and any subsequent cycles.
The requirements for ice detection and activation of the airframe
IPS are applicable to all phases of flight, unless it can be shown that
the airframe IPS need not be operated during specific phases of flight.
If the airframe IPS operates in a cyclical manner, it must either
include a system that automatically cycles the airframe IPS, or there
must be a method that alerts the flightcrew each time the airframe ice
protection system must be cycled. This final rule requires:
(e)(1) A primary IDS that automatically activates or
alerts the flightcrew to activate the airframe IPS;
(e)(2) A definition of visual cues for recognition of the
first sign of ice accretion on a specified surface combined with an
advisory IDS that alerts the flightcrew to activate the airframe IPS;
or
(e)(3) Identification of conditions conducive to airframe
icing as defined by an appropriate static or total air temperature and
visible moisture for use by the flightcrew to activate the airframe
IPS.
Any of the three ice detection methods will enable timely
activation of the airframe IPS and satisfy the requirements of this
final rule.
[[Page 38336]]
The first method of ice detection is the use of a primary IDS. A
primary IDS usually has two ice detectors. The cost of an ice detector
used in this analysis is based on the Goodrich Corporation's average
price of $6,000 per ice detector for a production airplane. The
Aviation Rulemaking Advisory Committee (ARAC) Ice Protection
Harmonization Working Group provided us with manufacturer cost
estimates for System Design, System Qualification, Hardware,
Installation, and Maintenance. Assuming the primary IDS has two ice
detectors, we estimate the average cost for a primary IDS to be about
$485,000 per certification, $12,000 ($6,000 x 2) for the hardware and
$2,500 for the installation, or $14,500 ($12,000 + $2,500) per
airplane. Table 1 shows a detailed breakout of these cost estimates.
One commenter to the NPRM, regarding Goodrich costs, stated there
was a cheaper alternative system than the Goodrich system. The FAA
notes a lower cost alternative is feasible.
Table 1--Costs for Sec. 25.1419(e)(1)--Primary Ice Detection System
----------------------------------------------------------------------------------------------------------------
Manufacturer non-recurring costs (per aircraft group/type) Additional
2006$ Hours Hourly rate cost Cost
----------------------------------------------------------------------------------------------------------------
System Design:
System architecture/Integration......................... 3,000 $75 ........... $225,000
Ice detector positioning................................ 300 75 ........... 22,500
Procedures for AFM, AOM/FCOM & MMEL..................... 200 75 ........... 15,000
System Qualification/certification:
Ice detector qualification.............................. 300 75 ........... 22,500
Ice detection system certification...................... 600 75 ........... 45,000
Flight tests............................................ 400 75 100,000 130,000
Installation Design:
Installation drawings................................... 500 50 ........... 25,000
---------------------------------------------------
Total............................................... 5,300 ........... ........... 485,000
============
Costs (per airplane):
Hardware (Primary Ice Detection System)................. ........... ........... 12,000 12,000
Installation............................................ 50 50 ........... 2,500
Additional weight is 5-10 kg............................ ........... ........... ........... 0
---------------------------------------------------
Total............................................... ........... ........... ........... 14,500
----------------------------------------------------------------------------------------------------------------
The second method of ice detection is the use of an advisory IDS
along with visual cues. The major difference between a primary and an
advisory IDS is that the primary is the principal means to determine
when the airframe IPS should be activated and has two ice detectors. In
contrast, an advisory IDS is a backup to the flightcrew and has only
one ice detector. The average cost for an advisory IDS is estimated to
be $447,500 per certification, $6,000 for the hardware and $1,250 for
the installation, or $7,250 ($6,000 + $1,250) per airplane. Table 2
shows a detailed breakout of these costs estimates.
Table 2--Costs for Sec. 25.1419(e)(2)--Advisory Ice Detection System and Visual Cues
----------------------------------------------------------------------------------------------------------------
Manufacturer non-recurring costs (per aircraft group/type) Additional
2006$ Hours Hourly rate cost Cost
----------------------------------------------------------------------------------------------------------------
System Design:
System architecture/Integration......................... 2,500 $75 ........... $187,500
Ice detector positioning................................ 200 75 ........... 15,000
Visual cue determination/design......................... 200 75 ........... 15,000
Procedures for AFM, AOM/FCOM & MMEL..................... 200 75 ........... 15,000
System Qualification/certification:
Ice detection qualification............................. 300 75 ........... 22,500
Visual cue substantiation............................... 200 75 ........... 15,000
Ice detection system certification...................... 300 75 ........... 22,500
Flight tests............................................ 400 75 $100,000 130,000
Installation Design:
Installation drawings................................... 500 50 ........... 25,000
---------------------------------------------------
Total............................................... 4,800 ........... ........... 447,500
===================================================
Costs (per airplane):
Hardware (Advisory Ice Detection System)................ ........... ........... 6,000 6,000
Installation............................................ 25 50 ........... 1,250
Additional weight is 5-10 kg............................ ........... ........... ........... 0
---------------------------------------------------
Total............................................... ........... ........... ........... 7,250
----------------------------------------------------------------------------------------------------------------
The third method of ice detection is a definition of conditions
conducive to airframe icing that will be used by the flightcrew to
activate the airframe IPS. This definition will be included in the
Airplane Flight Manual. There are no
[[Page 38337]]
costs imposed on the airplane manufacturers with this option. Table 3
shows a summary of the costs for each alternative.
Table 3--Cost Summary--Sec. 25.1419(e)
------------------------------------------------------------------------
Costs
------------------------------------
Per certification Per airplane
------------------------------------------------------------------------
Sec. 25.1419
