Special Conditions: Embraer S.A. Model ERJ 190-300 Airplane; Flight Envelope Protection: High Incidence Protection System, 37806-37811 [2017-17072]
Download as PDF
37806
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
same novel or unusual design feature,
these special conditions would also
apply to the other model under § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the Beechcraft Model 400A
airplanes must comply with the fuelvent and exhaust-emission requirements
of 14 CFR part 34, and the noisecertification requirements of 14 CFR
part 36.
The FAA issues special conditions, as
defined in 14 CFR 11.19, in accordance
with § 11.38, and they become part of
the type certification basis under
§ 21.101.
Novel or Unusual Design Features
The Beechcraft Model 400A airplanes,
as modified by Garmin, will incorporate
the following novel or unusual design
feature:
Installation of the Garmin G5000
satellite-based navigation system into
the airplanes.
sradovich on DSK3GMQ082PROD with RULES
Discussion
The Garmin G5000 satellite-based
navigation-system design, installed in
Beechcraft Model 400A airplanes,
introduces the potential for
unauthorized persons, accessing the
passenger-services domain, to access the
airplane-control domain and airplane
information-services domain; and
further may introduce security
vulnerabilities related to the
introduction of viruses, worms, user
errors, and intentional sabotage of
airplane networks, systems, and
databases.
The operating systems for current
airplane systems usually are
proprietary. Therefore, they are not as
susceptible to corruption from worms,
viruses, and other malicious actions as
are more widely used commercial
operating systems, such as Microsoft
Windows, because access to the design
details of these proprietary operating
systems is limited to the system
developer and airplane integrator. Some
systems installed on the Beechcraft
Model 400A airplanes will use
operating systems that are widely used
and commercially available from thirdparty software suppliers. The security
vulnerabilities of these operating
systems may be more widely known
than proprietary operating systems
currently used by avionics
manufacturers.
These special conditions contain the
additional safety standards that the
Administrator considers necessary to
establish a level of safety equivalent to
that established by the existing
airworthiness standards.
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
Applicability
DEPARTMENT OF TRANSPORTATION
As discussed above, these special
conditions are applicable to Beechcraft
Model 400A airplanes modified by
Garmin. Should Garmin apply at a later
date for a supplemental type certificate
to incorporate the same novel or
unusual design feature for any other
model included on the same type
certificate, these special conditions
would apply to that model as well.
Federal Aviation Administration
Conclusion
AGENCY:
This action affects only a certain
novel or unusual design feature on one
model of airplane. It is not a rule of
general applicability and affects only
the applicant who applied to the FAA
for approval of this feature on the
airplane.
SUMMARY:
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
The Special Conditions
Accordingly, pursuant to the
authority delegated to me by the
Administrator, the following special
conditions are issued as part of the type
certification basis for Beechcraft Model
400A airplanes modified by Garmin.
1. The applicant must ensure that the
design provides isolation from, or
airplane electronic-system security
protection against, access by
unauthorized sources internal to the
airplane. The design must prevent
inadvertent and malicious changes to,
and all adverse impacts upon, airplane
equipment, systems, networks, or other
assets required for safe flight and
operations.
2. The applicant must establish
appropriate procedures to allow the
operator to ensure that continued
airworthiness of the airplane is
maintained, including all post-typecertification modifications that may
have an impact on the approved
electronic-system security safeguards.
Issued in Renton, Washington, on July 31,
2017.
Victor Wicklund,
Manager, Transport Standards Branch,
Aircraft Certification Service.
[FR Doc. 2017–17071 Filed 8–11–17; 8:45 am]
BILLING CODE 4910–13–P
PO 00000
Frm 00002
Fmt 4700
Sfmt 4700
14 CFR Part 25
[Docket No. FAA–2017–0316; Special
Conditions No. 25–699–SC]
Special Conditions: Embraer S.A.
Model ERJ 190–300 Airplane; Flight
Envelope Protection: High Incidence
Protection System
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions; request
for comments.
These special conditions are
issued for the Embraer S.A. (Embraer)
Model ERJ 190–300 airplane. This
airplane will have a novel or unusual
design feature when compared to the
state of technology envisioned in the
airworthiness standards for transportcategory airplanes. This design feature
is a high-incidence protection function
that limits the angle of attack (AOA) at
which the airplane can be flown during
normal low-speed operation, and that
cannot be overridden by the flightcrew.
The applicable airworthiness
regulations do not contain adequate or
appropriate safety standards for this
design feature. These special conditions
contain the additional safety standards
that the Administrator considers
necessary to establish a level of safety
equivalent to that established by the
existing airworthiness standards.
DATES: This action is effective on
Embraer S.A. on August 14, 2017. We
must receive your comments by
September 28, 2017.
ADDRESSES: Send comments identified
by docket number FAA–2017–0316
using any of the following methods:
• Federal eRegulations Portal: Go to
https://www.regulations.gov/and follow
the online instructions for sending your
comments electronically.
• Mail: Send comments to Docket
Operations, M–30, U.S. Department of
Transportation (DOT), 1200 New Jersey
Avenue SE., Room W12–140, West
Building Ground Floor, Washington, DC
20590–0001.
• Hand Delivery or Courier: Take
comments to Docket Operations in
Room W12–140 of the West Building
Ground Floor at 1200 New Jersey
Avenue SE., Washington, DC, between 9
a.m. and 5 p.m., Monday through
Friday, except Federal holidays.
• Fax: Fax comments to Docket
Operations at 202–493–2251.
Privacy: The FAA will post all
comments it receives, without change,
to https://www.regulations.gov/,
E:\FR\FM\14AUR1.SGM
14AUR1
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
sradovich on DSK3GMQ082PROD with RULES
including any personal information the
commenter provides. Using the search
function of the docket Web site, anyone
can find and read the electronic form of
all comments received into any FAA
docket, including the name of the
individual sending the comment (or
signing the comment for an association,
business, labor union, etc.). DOT’s
complete Privacy Act Statement can be
found in the Federal Register published
on April 11, 2000 (65 FR 19477–19478).
Docket: Background documents or
comments received may be read at
https://www.regulations.gov/ at any time.
Follow the online instructions for
accessing the docket or go to Docket
Operations in Room W12–140 of the
West Building Ground Floor at 1200
New Jersey Avenue SE., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Joe
Jacobsen, FAA, Airplane and Flight
Crew Interface, ANM–111, Transport
Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington 98057–3356;
telephone 425–227–2011; facsimile
425–227–1320.
SUPPLEMENTARY INFORMATION: The
substance of these special conditions
has been subject to the notice and
comment period in several prior
instances and has been derived without
substantive change from those
previously issued. It is unlikely that
prior public comment would result in a
significant change from the substance
contained herein. Therefore, because a
delay would significantly affect the
certification of the airplane, the FAA
has determined that prior public notice
and comment are unnecessary and
impracticable.
In addition, since the substance of
these special conditions has been
subject to the public comment process
in several prior instances with no
substantive comments received, the
FAA finds it unnecessary to delay the
effective date and finds that good cause
exists for adopting these special
conditions upon publication in the
Federal Register.
The FAA is requesting comments to
allow interested persons to submit
views that may not have been submitted
in response to the prior opportunities
for comment described above.
Comments Invited
We invite interested people to take
part in this rulemaking by sending
written comments, data, or views. The
most helpful comments reference a
specific portion of the special
conditions, explain the reason for any
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
recommended change, and include
supporting data.
We will consider all comments we
receive by the closing date for
comments. We may change these special
conditions based on the comments we
receive.
Background
On September 13, 2013, Embraer
applied for an amendment to Type
Certificate No. A57NM to include the
new Model ERJ 190–300 airplane. The
Model ERJ 190–300 airplane, which is a
derivative of the Embraer Model ERJ
190–100 STD airplane currently
approved under Type Certificate No.
A57NM, is a 97- to 114-passenger
transport-category airplane, designed
with a new wing with a high aspect
ratio and raked wingtip, and a new
electrical-distribution system. The
maximum take-off weight is 124,340 lbs
(56,400 kg).
Type Certification Basis
Under the provisions of title 14, Code
of Federal Regulations (14 CFR) 21.101,
Embraer must show that the Model ERJ
190–300 airplane meets the applicable
provisions of the regulations listed in
Type Certificate No. A57NM, or the
applicable regulations in effect on the
date of application for the change,
except for earlier amendments as agreed
upon by the FAA.
If the Administrator finds that the
applicable airworthiness regulations
(i.e., 14 CFR part 25) do not contain
adequate or appropriate safety standards
for the Model ERJ 190–300 airplane
because of a novel or unusual design
feature, special conditions are
prescribed under the provisions of
§ 21.16.
Special conditions are initially
applicable to the model for which they
are issued. Should the type certificate
for that model be amended later to
include any other model that
incorporates the same novel or unusual
design feature, or should any other
model already included on the same
type certificate be modified to
incorporate the same novel or unusual
design feature, these special conditions
would also apply to the other model
under § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the Embraer Model ERJ 190–
300 airplane must comply with the fuelvent and exhaust-emission requirements
of 14 CFR part 34, and the noisecertification requirements of 14 CFR
part 36.
The FAA issues special conditions, as
defined in 14 CFR 11.19, in accordance
with § 11.38, and they become part of
PO 00000
Frm 00003
Fmt 4700
Sfmt 4700
37807
the type certification basis under
§ 21.101.
Novel or Unusual Design Features
The Embraer Model ERJ 190–300
airplane will incorporate the following
novel or unusual design feature:
A high-incidence protection function
that limits the angle of attack (AOA) at
which the airplane can be flown during
normal low-speed operation, and that
cannot be overridden by the flightcrew.
Discussion
The Model ERJ 190–300 airplane
design has a complex, full-digital flightcontrol system, referred to as fly-by-wire
(FBW) architecture. This FBW
architecture provides closed-loop flightcontrol laws and multiple protection
functions.
The Model ERJ 190–300 airplane is
equipped with a high-incidence
protection function that limits the angle
of attack (AOA) at which the airplane
can be flown during normal low-speed
operation, and cannot be overridden by
the flightcrew. The application of this
AOA limit impacts the stall-speed
determination, the stall characteristics
and stall-warning demonstration, and
the longitudinal airplane-handling
characteristics. The high-incidence
protection function prevents the
airplane from stalling at low speeds and,
therefore, a stall warning system is
backed up during normal flight
conditions. If the high-incidence
protection function has a failure that is
not shown to be extremely improbable,
stall warning must be provided in a
conventional manner. Also, the flight
characteristics at the AOA for VCLmax
(AOA at the maximum lift co-efficient
and associated speed) must be suitable
in the traditional sense. Per 14 CFR
21.16, therefore, special conditions are
needed to address the unique features of
the high-incidence protection function
installed on the Model ERJ 190–300
airplane.
These special conditions contain the
additional safety standards that the
Administrator considers necessary to
establish a level of safety equivalent to
that established by the existing
airworthiness standards.
Applicability
As discussed above, these special
conditions are applicable to the Model
ERJ 190–300 airplane. Should Embraer
apply at a later date for a change to the
type certificate to include another
model incorporating the same novel or
unusual design feature, these special
conditions would apply to that model as
well.
E:\FR\FM\14AUR1.SGM
14AUR1
37808
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
Conclusion
This action affects only certain novel
or unusual design features on one model
of airplane. It is not a rule of general
applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
The Special Conditions
Accordingly, pursuant to the
authority delegated to me by the
Administrator, the following special
conditions are issued as part of the type
certification basis for the Embraer
Model ERJ 190–300 airplane.
Flight Envelope Protection: High
Incidence Protection System
The current airworthiness standards
do not contain adequate safety
standards for the unique features of the
high incidence protection system on the
Embraer Model ERJ 190–300 airplane.
Part I of the following special conditions
are issued in lieu of the specified
paragraphs of §§ 25.103, 25.145, 25.201,
25.203, 25.207, and 25.1323 of title 14,
Code of Federal Regulations (CFR) or in
addition to the requirements of § 25.21.
Part II are in lieu of the specified
paragraphs of §§ 25.103, 25.105, 25.107,
25.121, 25.123, 25.125, 25.143, and
25.207 of title 14 CFR.
Special Conditions Part I
Stall Protection and Scheduled
Operating Speeds
The following special conditions are
in lieu of §§ 25.103, 25.145(a),
25.145(b)(6), 25.201, 25.203, 25.207, and
25.1323(d) or in addition to the
requirements of § 25.21.
Foreword
sradovich on DSK3GMQ082PROD with RULES
In the following paragraphs, ‘‘in icing
conditions’’ means with the ice
accretions (relative to the relevant flight
phase) as defined in 14 CFR part 25,
Amendment 121, appendix C.
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
1. Definitions
The following are terms relating to the
novel or unusual design features these
special conditions address:
• High incidence protection system: A
system that operates directly and
automatically on the airplane’s flying
controls to limit the maximum angle of
attack that can be attained to a value
below that at which an aerodynamic
stall would occur.
• Alpha-limit: The maximum angle of
attack at which the airplane stabilizes
with the high incidence protection
system operating, and the longitudinal
control held on its aft stop.
• Vmin: The minimum steady flight
speed in the airplane configuration
under consideration with the high
incidence protection system operating.
See Part I, section 3 of these special
conditions.
• Vmin1g: Vmin corrected to 1g
conditions. See Part I, section 3 of these
special conditions. It is the minimum
calibrated airspeed at which the
airplane can develop a lift force normal
to the flight path and equal to its weight
when at an angle of attack not greater
than that determined for Vmin.
2. Capability and Reliability of the High
Incidence Protection System
The capability and reliability of the
high incidence protection system can be
established by flight test, simulation,
and analysis as appropriate. The
capability and reliability required are as
follows:
1. It must not be possible during pilotinduced maneuvers to encounter a stall,
and handling characteristics must be
acceptable, as required by section 5 of
Part I of these special conditions.
2. The airplane must be protected
against stalling due to the effects of
wind-shears and gusts at low speeds as
required by section 6 of Part I of these
special conditions.
3. The ability of the high incidence
protection system to accommodate any
reduction in stalling incidence must be
verified in icing conditions.
4. The high incidence protection
system must be provided in each
abnormal configuration of the high lift
devices that is likely to be used in flight
following system failures.
PO 00000
Frm 00004
Fmt 4700
Sfmt 4700
5. The reliability of the system and
the effects of failures must be acceptable
in accordance with § 25.1309.
3. Minimum Steady Flight Speed and
Reference Stall Speed
In lieu of § 25.103, the following
requirements apply:
(a) The minimum steady flight speed,
Vmin, is the final stabilized calibrated
airspeed obtained when the airplane is
decelerated until the longitudinal
control is on its stop in such a way that
the entry rate does not exceed 1 knot per
second.
(b) The minimum steady flight speed,
Vmin, must be determined if it is used to
determine compliance with a required
performance standard or other
requirements demonstrations in icing or
non-icing conditions with:
(1) The high incidence protection
system operating normally;
(2) Idle thrust and automatic thrust
system (if applicable) inhibited;
(3) All combinations of flap settings
and landing gear position for which Vmin
is required to be determined;
(4) The weight used when reference
stall speed, VSR, is being used as a factor
to determine compliance with a
required performance standard;
(5) The most unfavorable center of
gravity allowable; and
(6) The airplane trimmed for straight
flight at a speed selected by the
applicant, but not less than 1.13 VSR and
not greater than 1.3 VSR.
(c) The 1-g minimum steady flight
speed, Vmin1g, is the minimum
calibrated airspeed at which the
airplane can develop a lift force (normal
to the flight path) equal to its weight,
while at an angle of attack not greater
than that at which the minimum steady
flight speed of subparagraph (a) was
determined. It must be determined if it
is used to determine compliance with a
required performance standard or other
requirements demonstrations in icing or
non-icing conditions.
(d) The reference stall speed, VSR, is
a calibrated airspeed defined by the
applicant. VSR may not be less than a 1g
stall speed. VSR must be determined in
non-icing conditions (and as an option,
in icing conditions) and expressed as:
E:\FR\FM\14AUR1.SGM
14AUR1
(e) VCLmax is determined with:
(1) Engines idling, or, if that resultant
thrust causes an appreciable decrease in
stall speed, not more than zero thrust at
the stall speed;
(2) The airplane in other respects
(such as flaps, landing gear, and ice
accretions) in the condition existing in
the test or performance standard in
which VSR is being used;
(3) The weight used when VSR is
being used as a factor to determine
compliance with a required
performance standard;
(4) The center of gravity position that
results in the highest value of reference
stall speed;
(5) The airplane trimmed for straight
flight at a speed achievable by the
automatic trim system, but not less than
1.13 VSR and not greater than 1.3 VSR;
and
(6) The high incidence protection
system adjusted or disabled, at the
option of the applicant, to allow higher
incidence than is possible with the
normal production system.
(7) Starting from the stabilized trim
condition, apply the longitudinal
control to decelerate the airplane so that
the speed reduction does not exceed 1
knot per second.
4. Stall Warning
In lieu of § 25.207, the following
requirements apply:
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
4.1
Normal Operation
If the capability requirements of the
high incidence protection system are
successfully demostrated, then the
conditions of section 2, ‘‘Capability and
Reliability of the High Incidence
Protection System,’’ are satisfied. These
conditions provide safety equivalent to
§ 25.207, Stall warning, so the provision
of an additional, unique warning device
is not required.
4.2 High Incidence Protection System
Failure
Following failures of the high
incidence protection system, not shown
to be extremely improbable, such that
the capability of the system no longer
satisfies items (1), (2), and (3) of section
2, ‘‘Capability and Reliability of the
High Incidence Protection System,’’ stall
warning must be provided and must
protect against encountering
unacceptable stall characteristics and
against encountering stall.
(a) Stall warning with the flaps and
landing gear in any normal position
must be clear and distinctive to the pilot
and meet the requirements specified in
paragraphs (d) and (e) below.
(b) Stall warning must also be
provided in each abnormal
configuration of the high lift devices
that is likely to be used in flight
following system failures.
PO 00000
Frm 00005
Fmt 4700
Sfmt 4700
37809
(c) The warning may 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) above and
for the conditions prescribed in
paragraphs (d) and (e) below.
(d) In non-icing conditions stall
warning must provide sufficient margin
to prevent encountering unacceptable
stall characteristics and encountering
stall in the following conditions:
(1) In power off (engine power or
thrust at flight idle) straight deceleration
not exceeding 1 knot per second to a
speed 5 knots or 5 percent calibrated
airspeed, whichever is greater, below
the warning onset.
(2) In turning flight stall deceleration
at entry rates up to 3 knots per second
when recovery is initiated not less than
1 second after the warning onset.
(e) In icing conditions stall warning
must provide sufficient margin to
prevent encountering unacceptable
characteristics and encountering stall, in
power-off (engine power or thrust at
flight idle) straight and turning flight
decelerations not exceeding 1 knot per
E:\FR\FM\14AUR1.SGM
14AUR1
ER14AU17.027
sradovich on DSK3GMQ082PROD with RULES
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
37810
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
second, when the pilot starts a recovery
maneuver not less than three seconds
after the onset of stall warning.
(f) An airplane is considered stalled
when the behavior of the airplane gives
the pilot a clear and distinctive
indication of an acceptable nature that
the airplane is stalled. Acceptable
indications of a stall, occurring either
individually or in combination are:
(1) A nose-down pitch that cannot be
readily arrested;
(2) Buffeting, of a magnitude and
severity that is strong and effective
deterrent to further speed reduction; or
(3) The pitch control reaches the aft
stop and no further increase in pitch
attitude occurs when the control is held
full aft for a short time before recovery
is initiated.
(g) An aircraft exhibits unacceptable
characteristics during straight or turning
flight decelerations if it is not always
possible to produce and to correct roll
and yaw by unreversed use of aileron
and rudder controls, or abnormal noseup pitching occurs.
5. Handling Characteristics at High
Incidence
In lieu of §§ 25.201 and 25.203, the
following requirements apply:
sradovich on DSK3GMQ082PROD with RULES
5.1 High Incidence Handling
Demonstration
In lieu of § 25.201:
(a) Maneuvers to the limit of the
longitudinal control, in the nose-up
pitch, must be demonstrated in straight
flight and in 30° banked turns with:
(1) The high incidence protection
system operating normally;
(2) Initial power conditions of:
i. Power off (engine power or thrust at
flight idle); and
ii. The power necessary to maintain
level flight at 1.5 VSR1, where VSR1 is the
reference stall speed with flaps in
approach position, the landing gear
retracted, and maximum landing
weight;
(3) Flaps, landing gear, and
deceleration devices in any likely
combination of positions;
(4) Representative weights within the
range for which certification is
requested; and
(5) The airplane trimmed for straight
flight at a speed selected by the
applicant, but not less than 1.13 V SR
and not greater than 1.3 VSR.
(b) The following procedures must be
used to show compliance in non-icing
and icing conditions:
(1) Starting at a speed sufficiently
above the minimum steady flight speed
to ensure that a steady rate of speed
reduction can be established, apply the
longitudinal control so that the speed
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
reduction does not exceed 1 knot per
second until the control reaches the
stop;
(2) The longitudinal control must be
maintained at the stop until the airplane
has reached a stabilized flight condition
and must then be recovered by normal
recovery techniques;
(3) Maneuvers with increased
deceleration rates:
(i) In non-icing conditions, the
requirements must also be met with
increased rates of entry to the incidence
limit, up to the maximum practical
entry rate; and
(ii) In icing conditions, with the antiice system working normally, the
requirements must also be met with
increased rates of entry to the incidence
limit, up to 3 knots per second; and
(4) Maneuver with ice accretion prior
to operation of the normal anti-ice
system. With the ice accretion prior to
operation of the normal anti-ice system,
the requirements must also be met in
deceleration at 1 knot per second. The
deceleration must be continued until
one second after the activation of the
tactile stall warning system or three
seconds after reaching full back stick,
whichever occurs first. A primary ice
detection system must automatically
activate the ice protection.
5.2 Characteristics in High Incidence
Maneuvers
In lieu of § 25.203:
In icing and non-icing conditions:
(a) Throughout maneuvers with a rate
of deceleration of not more than 1 knot
per second, both in straight flight and in
30° banked turns, the airplane’s
characteristics must be as follows:
(1) There must not be any abnormal
nose-up pitching.
(2) There must not be any
uncommanded nose-down pitching,
which would be indicative of stall.
However, reasonable attitude changes
associated with stabilizing the incidence
at Alpha limit as the longitudinal
control reaches the stop would be
acceptable.
(3) There must not be any
uncommanded lateral or directional
motion and the pilot must retain good
lateral and directional control, by
conventional use of the controls,
throughout the maneuver.
(4) The airplane must not exhibit
buffeting of a magnitude and severity
that would act as a deterrent from
completing the maneuver specified in
paragraph 5.1(a).
(b) In maneuvers with increased rates
of deceleration, some degradation of
characteristics is acceptable, associated
with a transient excursion beyond the
stabilized Alpha limit. However, the
PO 00000
Frm 00006
Fmt 4700
Sfmt 4700
airplane must not exhibit dangerous
characteristics or characteristics that
would deter the pilot from holding the
longitudinal control on the stop for a
period of time appropriate to the
maneuver.
(c) It must always be possible to
reduce incidence by conventional use of
the controls.
(d) The rate at which the airplane can
be maneuvered from trim speeds
associated with scheduled operating
speeds such as V2 and VREF up to Alpha
limit must not be unduly damped or be
significantly slower than can be
achieved on conventionally controlled
transport airplanes.
5.3 Characteristics Up to Maximum
Lift Angle of Attack
Also in lieu of § 25.201:
(a) In non-icing conditions:
Maneuvers with a rate of deceleration
of not more than 1 knot per second up
to the angle of attack at which VCLmax
was obtained as defined in section 3,
‘‘Minimum Steady Flight Speed and
Reference Stall Speed,’’ must be
demonstrated in straight flight and in
30° banked turns in the following
configurations:
(1) The high incidence protection
deactivated or adjusted, at the option of
the applicant, to allow higher incidence
than is possible with the normal
production system;
(2) Automatic thrust increase system
inhibited (if applicable);
(3) Engines idling;
(4) Flaps and landing gear in any
likely combination of positions; and
(5) The airplane trimmed for straight
flight at a speed selected by the
applicant, but not less than 1.13 VSR and
not greater than 1.3 VSR.
(b) In icing conditions:
Maneuvers with a rate of deceleration
of not more than 1 knot per second up
to the maximum angle of attack reached
during maneuvers from paragraph
5.1(b)(3)(ii) must be demonstrated in
straight flight with:
(1) The high incidence protection
deactivated or adjusted, at the option of
the applicant, to allow higher incidence
than is possible with the normal
production system;
(2) Automatic thrust increase system
inhibited (if applicable);
(3) Engines idling;
(4) Flaps and landing gear in any
likely combination of positions, and
(5) The airplane trimmed for straight
flight at a speed achievable by the
automatic trim system.
(c) During the maneuvers used to
show compliance with paragraphs (a)
and (b) above, the airplane must not
exhibit dangerous characteristics, and it
E:\FR\FM\14AUR1.SGM
14AUR1
Federal Register / Vol. 82, No. 155 / Monday, August 14, 2017 / Rules and Regulations
must always be possible to reduce angle
of attack by conventional use of the
controls. The pilot must retain good
lateral and directional control, by
conventional use of the controls,
throughout the maneuver.
6. Atmospheric Disturbances
Operation of the high incidence
protection system must not adversely
affect aircraft control during expected
levels of atmospheric disturbances, nor
impede the application of recovery
procedures in case of wind-shear. This
must be demonstrated in non-icing and
icing conditions.
7. Proof of Compliance
In addition to the requirements of
§ 25.21, the following requirement
applies:
(b) The flying qualities must be
evaluated at the most unfavorable
center-of-gravity position.
8. Sections 25.145(a), 25.145(b)(6), and
25.1323(d)
The following requirements apply:
• For § 25.145(a), add ‘‘Vmin’’ in lieu
of ‘‘stall identification.’’
• For § 25.145(b)(6), and ‘‘Vmin’’ in
lieu of ‘‘VSW.’’
• For § 25.1323(d), add ‘‘From 1.23
VSR to Vmin . . .,’’ in lieu of, ‘‘1.23 VSR
to the speed at which stall warning
begins . . .,’’ and, ‘‘. . . speeds below
Vmin . . .’’ in lieu of, ‘‘. . . speeds below
stall warning.’’
sradovich on DSK3GMQ082PROD with RULES
Special Conditions Part II
Credit for Robust Envelope Protection
in Icing Conditions
The following special conditions are
in lieu of the specified paragraphs of
§§ 25.103, 25.105, 25.107, 25.121,
25.123, 25.125, 25.143, and 25.207.
1. Define the stall speed as provided
in these special conditions, Part I, in
lieu of § 25.103.
2. In lieu of § 25.105(a)(2)(i), the
following requirement applies:
(i) The V2 speed scheduled in nonicing conditions does not provide the
maneuvering capability specified in
§ 25.143(h) for the takeoff configuration,
or
3. In lieu of § 25.107(c) and (g), the
following requirements apply, with
additional sections (c′) and (g′):
Takeoff speeds:
(c) In non-icing conditions V2, in
terms of calibrated airspeed, must be
selected by the applicant to provide at
least the gradient of climb required by
§ 25.121(b) but may not be less than—
(1) V2MIN;
(2) VR plus the speed increment
attained (in accordance with
§ 25.111(c)(2)) before reaching a height
of 35 feet above the takeoff surface; and
VerDate Sep<11>2014
15:51 Aug 11, 2017
Jkt 241001
(3) A speed that provides the
maneuvering capability specified in
§ 25.143(h).
(c′) In icing conditions with the
‘‘takeoff ice’’ accretion defined in part
25, appendix C, V2 may not be less
than—
(1) The V2 speed determined in nonicing conditions; and
(2) A speed that provides the
maneuvering capability specified in
§ 25.143(h).
(g) In non-icing conditions, VFTO, in
terms of calibrated airspeed, must be
selected by the applicant to provide at
least the gradient of climb required by
§ 25.121(c), but may not be less than—
(1) 1.18 VSR; and
(2) A speed that provides the
maneuvering capability specified in
§ 25.143(h).
(g′) In icing conditions with the ‘‘final
takeoff ice’’ accretion defined in part 25,
appendix C, VFTO, may not be less
than—
(1) The VFTO speed determined in
non-icing conditions.
(2) A speed that provides the
maneuvering capability specified in
§ 25.143(h).
4. In lieu of §§ 25.121(b)(2)(ii)(A),
25.121(c)(2)(ii)(A), and 25.121(d)(2)(ii),
the following requirements apply:
In lieu of § 25.121(b)(2)(ii)(A):
(A) The V2 speed scheduled in nonicing conditions does not provide the
maneuvering capability specified in
§ 25.143(h) for the takeoff configuration;
or
In lieu of § 25.121(c)(2)(ii)(A):
(A) The VFTO speed scheduled in nonicing conditions does not provide the
maneuvering capability specified in
§ 25.143(h) for the en-route
configuration; or
In lieu of § 25.121(d)(2)(ii):
(d)(2) The requirements of
subparagraph (d)(1) of this paragraph
must be met: (ii) In icing conditions
with the approach ice accretion defined
in appendix C, in a configuration
corresponding to the normal all-enginesoperating procedure in which Vmin1g for
this configuration does not exceed
110% of the Vmin1g for the related allengines-operating landing configuration
in icing, with a climb speed established
with normal landing procedures, but not
more than 1.4 VSR (VSR determined in
non-icing conditions).
5. In lieu of § 25.123(b)(2)(i), the
following requirements apply:
(i) The minimum en-route speed
scheduled in non-icing conditions does
not provide the maneuvering capability
specified in § 25.143(h) for the en-route
configuration, or
6. In lieu of §§ 25.125(b)(2)(ii)(B) and
25.125(b)(2)(ii)(C), the following
requirements apply:
PO 00000
Frm 00007
Fmt 4700
Sfmt 4700
37811
(B) A speed that provides the
maneuvering capability specified in
§ 25.143(h) with the landing ice
accretion defined in part 25, appendix
C.
(C) 1.17 Vmin1g.
7. In lieu of § 25.143(j)(1), the
following requirement applies:
(1) The airplane is controllable in a
pull-up maneuver up to 1.5 g load factor
or lower if limited by angle of attack
protection; and
8. In lieu of § 25.207, Stall warning, to
read as the requirements defined in
these special conditions Part I, Section
4.
Issued in Renton, Washington, on July 31,
2017.
Victor Wicklund,
Manager, Transport Standards Branch,
Aircraft Certification Service.
[FR Doc. 2017–17072 Filed 8–11–17; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2017–0484; Special
Conditions No. 25–700–SC]
Special Conditions: Textron Aviation
Inc. Model 700 Airplanes; Use of
Automatic Power Reserve for GoAround Performance Credit
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions; request
for comments.
AGENCY:
These special conditions are
issued for the Textron Aviation Inc.
(Textron) Model 700 airplane. This
airplane will have a novel or unusual
design feature when compared to the
state of technology envisioned in the
airworthiness standards for transportcategory airplanes. This design feature
is an Automatic Takeoff Thrust Control
System (ATTCS), referred to as an
Automatic Power Reserve (APR), to set
the performance level for approachclimb operation after an engine failure.
The applicable airworthiness
regulations do not contain adequate or
appropriate safety standards for this
design feature. These special conditions
contain the additional safety standards
that the Administrator considers
necessary to establish a level of safety
equivalent to that established by the
existing airworthiness standards.
DATES: This action is effective on
Textron on August 14, 2017. Send your
comments by September 28, 2017.
SUMMARY:
E:\FR\FM\14AUR1.SGM
14AUR1
Agencies
[Federal Register Volume 82, Number 155 (Monday, August 14, 2017)]
[Rules and Regulations]
[Pages 37806-37811]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-17072]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2017-0316; Special Conditions No. 25-699-SC]
Special Conditions: Embraer S.A. Model ERJ 190-300 Airplane;
Flight Envelope Protection: High Incidence Protection System
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Embraer S.A.
(Embraer) Model ERJ 190-300 airplane. This airplane will have a novel
or unusual design feature when compared to the state of technology
envisioned in the airworthiness standards for transport-category
airplanes. This design feature is a high-incidence protection function
that limits the angle of attack (AOA) at which the airplane can be
flown during normal low-speed operation, and that cannot be overridden
by the flightcrew. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for this design
feature. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the existing
airworthiness standards.
DATES: This action is effective on Embraer S.A. on August 14, 2017. We
must receive your comments by September 28, 2017.
ADDRESSES: Send comments identified by docket number FAA-2017-0316
using any of the following methods:
Federal eRegulations Portal: Go to https://www.regulations.gov/and follow the online instructions for sending your
comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to https://www.regulations.gov/,
[[Page 37807]]
including any personal information the commenter provides. Using the
search function of the docket Web site, anyone can find and read the
electronic form of all comments received into any FAA docket, including
the name of the individual sending the comment (or signing the comment
for an association, business, labor union, etc.). DOT's complete
Privacy Act Statement can be found in the Federal Register published on
April 11, 2000 (65 FR 19477-19478).
Docket: Background documents or comments received may be read at
https://www.regulations.gov/ at any time. Follow the online instructions
for accessing the docket or go to Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE.,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Airplane and Flight
Crew Interface, ANM-111, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2011; facsimile 425-227-1320.
SUPPLEMENTARY INFORMATION: The substance of these special conditions
has been subject to the notice and comment period in several prior
instances and has been derived without substantive change from those
previously issued. It is unlikely that prior public comment would
result in a significant change from the substance contained herein.
Therefore, because a delay would significantly affect the certification
of the airplane, the FAA has determined that prior public notice and
comment are unnecessary and impracticable.
In addition, since the substance of these special conditions has
been subject to the public comment process in several prior instances
with no substantive comments received, the FAA finds it unnecessary to
delay the effective date and finds that good cause exists for adopting
these special conditions upon publication in the Federal Register.
The FAA is requesting comments to allow interested persons to
submit views that may not have been submitted in response to the prior
opportunities for comment described above.
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data.
We will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On September 13, 2013, Embraer applied for an amendment to Type
Certificate No. A57NM to include the new Model ERJ 190-300 airplane.
The Model ERJ 190-300 airplane, which is a derivative of the Embraer
Model ERJ 190-100 STD airplane currently approved under Type
Certificate No. A57NM, is a 97- to 114-passenger transport-category
airplane, designed with a new wing with a high aspect ratio and raked
wingtip, and a new electrical-distribution system. The maximum take-off
weight is 124,340 lbs (56,400 kg).
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Embraer must show that the Model ERJ 190-300 airplane
meets the applicable provisions of the regulations listed in Type
Certificate No. A57NM, or the applicable regulations in effect on the
date of application for the change, except for earlier amendments as
agreed upon by the FAA.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Model ERJ 190-300 airplane because
of a novel or unusual design feature, special conditions are prescribed
under the provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the Embraer Model ERJ 190-300 airplane must comply with the
fuel-vent and exhaust-emission requirements of 14 CFR part 34, and the
noise-certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Embraer Model ERJ 190-300 airplane will incorporate the
following novel or unusual design feature:
A high-incidence protection function that limits the angle of
attack (AOA) at which the airplane can be flown during normal low-speed
operation, and that cannot be overridden by the flightcrew.
Discussion
The Model ERJ 190-300 airplane design has a complex, full-digital
flight-control system, referred to as fly-by-wire (FBW) architecture.
This FBW architecture provides closed-loop flight-control laws and
multiple protection functions.
The Model ERJ 190-300 airplane is equipped with a high-incidence
protection function that limits the angle of attack (AOA) at which the
airplane can be flown during normal low-speed operation, and cannot be
overridden by the flightcrew. The application of this AOA limit impacts
the stall-speed determination, the stall characteristics and stall-
warning demonstration, and the longitudinal airplane-handling
characteristics. The high-incidence protection function prevents the
airplane from stalling at low speeds and, therefore, a stall warning
system is backed up during normal flight conditions. If the high-
incidence protection function has a failure that is not shown to be
extremely improbable, stall warning must be provided in a conventional
manner. Also, the flight characteristics at the AOA for
VCLmax (AOA at the maximum lift co-efficient and associated
speed) must be suitable in the traditional sense. Per 14 CFR 21.16,
therefore, special conditions are needed to address the unique features
of the high-incidence protection function installed on the Model ERJ
190-300 airplane.
These special conditions contain the additional safety standards
that the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
Applicability
As discussed above, these special conditions are applicable to the
Model ERJ 190-300 airplane. Should Embraer apply at a later date for a
change to the type certificate to include another model incorporating
the same novel or unusual design feature, these special conditions
would apply to that model as well.
[[Page 37808]]
Conclusion
This action affects only certain novel or unusual design features
on one model of airplane. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for the Embraer Model ERJ 190-300
airplane.
Flight Envelope Protection: High Incidence Protection System
The current airworthiness standards do not contain adequate safety
standards for the unique features of the high incidence protection
system on the Embraer Model ERJ 190-300 airplane. Part I of the
following special conditions are issued in lieu of the specified
paragraphs of Sec. Sec. 25.103, 25.145, 25.201, 25.203, 25.207, and
25.1323 of title 14, Code of Federal Regulations (CFR) or in addition
to the requirements of Sec. 25.21. Part II are in lieu of the
specified paragraphs of Sec. Sec. 25.103, 25.105, 25.107, 25.121,
25.123, 25.125, 25.143, and 25.207 of title 14 CFR.
Special Conditions Part I
Stall Protection and Scheduled Operating Speeds
The following special conditions are in lieu of Sec. Sec. 25.103,
25.145(a), 25.145(b)(6), 25.201, 25.203, 25.207, and 25.1323(d) or in
addition to the requirements of Sec. 25.21.
Foreword
In the following paragraphs, ``in icing conditions'' means with the
ice accretions (relative to the relevant flight phase) as defined in 14
CFR part 25, Amendment 121, appendix C.
1. Definitions
The following are terms relating to the novel or unusual design
features these special conditions address:
High incidence protection system: A system that operates
directly and automatically on the airplane's flying controls to limit
the maximum angle of attack that can be attained to a value below that
at which an aerodynamic stall would occur.
Alpha-limit: The maximum angle of attack at which the
airplane stabilizes with the high incidence protection system
operating, and the longitudinal control held on its aft stop.
Vmin: The minimum steady flight speed in the airplane
configuration under consideration with the high incidence protection
system operating. See Part I, section 3 of these special conditions.
Vmin1g: Vmin corrected to 1g conditions. See
Part I, section 3 of these special conditions. It is the minimum
calibrated airspeed at which the airplane can develop a lift force
normal to the flight path and equal to its weight when at an angle of
attack not greater than that determined for Vmin.
2. Capability and Reliability of the High Incidence Protection System
The capability and reliability of the high incidence protection
system can be established by flight test, simulation, and analysis as
appropriate. The capability and reliability required are as follows:
1. It must not be possible during pilot-induced maneuvers to
encounter a stall, and handling characteristics must be acceptable, as
required by section 5 of Part I of these special conditions.
2. The airplane must be protected against stalling due to the
effects of wind-shears and gusts at low speeds as required by section 6
of Part I of these special conditions.
3. The ability of the high incidence protection system to
accommodate any reduction in stalling incidence must be verified in
icing conditions.
4. The high incidence protection system must be provided in each
abnormal configuration of the high lift devices that is likely to be
used in flight following system failures.
5. The reliability of the system and the effects of failures must
be acceptable in accordance with Sec. 25.1309.
3. Minimum Steady Flight Speed and Reference Stall Speed
In lieu of Sec. 25.103, the following requirements apply:
(a) The minimum steady flight speed, Vmin, is the final
stabilized calibrated airspeed obtained when the airplane is
decelerated until the longitudinal control is on its stop in such a way
that the entry rate does not exceed 1 knot per second.
(b) The minimum steady flight speed, Vmin, must be
determined if it is used to determine compliance with a required
performance standard or other requirements demonstrations in icing or
non-icing conditions with:
(1) The high incidence protection system operating normally;
(2) Idle thrust and automatic thrust system (if applicable)
inhibited;
(3) All combinations of flap settings and landing gear position for
which Vmin is required to be determined;
(4) The weight used when reference stall speed, VSR, is
being used as a factor to determine compliance with a required
performance standard;
(5) The most unfavorable center of gravity allowable; and
(6) The airplane trimmed for straight flight at a speed selected by
the applicant, but not less than 1.13 VSR and not greater
than 1.3 VSR.
(c) The 1-g minimum steady flight speed, Vmin1g, is the
minimum calibrated airspeed at which the airplane can develop a lift
force (normal to the flight path) equal to its weight, while at an
angle of attack not greater than that at which the minimum steady
flight speed of subparagraph (a) was determined. It must be determined
if it is used to determine compliance with a required performance
standard or other requirements demonstrations in icing or non-icing
conditions.
(d) The reference stall speed, VSR, is a calibrated
airspeed defined by the applicant. VSR may not be less than
a 1g stall speed. VSR must be determined in non-icing
conditions (and as an option, in icing conditions) and expressed as:
[[Page 37809]]
[GRAPHIC] [TIFF OMITTED] TR14AU17.027
(e) VCLmax is determined with:
(1) Engines idling, or, if that resultant thrust causes an
appreciable decrease in stall speed, not more than zero thrust at the
stall speed;
(2) The airplane in other respects (such as flaps, landing gear,
and ice accretions) in the condition existing in the test or
performance standard in which VSR is being used;
(3) The weight used when VSR is being used as a factor
to determine compliance with a required performance standard;
(4) The center of gravity position that results in the highest
value of reference stall speed;
(5) The airplane trimmed for straight flight at a speed achievable
by the automatic trim system, but not less than 1.13 VSR and
not greater than 1.3 VSR; and
(6) The high incidence protection system adjusted or disabled, at
the option of the applicant, to allow higher incidence than is possible
with the normal production system.
(7) Starting from the stabilized trim condition, apply the
longitudinal control to decelerate the airplane so that the speed
reduction does not exceed 1 knot per second.
4. Stall Warning
In lieu of Sec. 25.207, the following requirements apply:
4.1 Normal Operation
If the capability requirements of the high incidence protection
system are successfully demostrated, then the conditions of section 2,
``Capability and Reliability of the High Incidence Protection System,''
are satisfied. These conditions provide safety equivalent to Sec.
25.207, Stall warning, so the provision of an additional, unique
warning device is not required.
4.2 High Incidence Protection System Failure
Following failures of the high incidence protection system, not
shown to be extremely improbable, such that the capability of the
system no longer satisfies items (1), (2), and (3) of section 2,
``Capability and Reliability of the High Incidence Protection System,''
stall warning must be provided and must protect against encountering
unacceptable stall characteristics and against encountering stall.
(a) Stall warning with the flaps and landing gear in any normal
position must be clear and distinctive to the pilot and meet the
requirements specified in paragraphs (d) and (e) below.
(b) Stall warning must also be provided in each abnormal
configuration of the high lift devices that is likely to be used in
flight following system failures.
(c) The warning may 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) above and for the
conditions prescribed in paragraphs (d) and (e) below.
(d) In non-icing conditions stall warning must provide sufficient
margin to prevent encountering unacceptable stall characteristics and
encountering stall in the following conditions:
(1) In power off (engine power or thrust at flight idle) straight
deceleration not exceeding 1 knot per second to a speed 5 knots or 5
percent calibrated airspeed, whichever is greater, below the warning
onset.
(2) In turning flight stall deceleration at entry rates up to 3
knots per second when recovery is initiated not less than 1 second
after the warning onset.
(e) In icing conditions stall warning must provide sufficient
margin to prevent encountering unacceptable characteristics and
encountering stall, in power-off (engine power or thrust at flight
idle) straight and turning flight decelerations not exceeding 1 knot
per
[[Page 37810]]
second, when the pilot starts a recovery maneuver not less than three
seconds after the onset of stall warning.
(f) An airplane is considered stalled when the behavior of the
airplane gives the pilot a clear and distinctive indication of an
acceptable nature that the airplane is stalled. Acceptable indications
of a stall, occurring either individually or in combination are:
(1) A nose-down pitch that cannot be readily arrested;
(2) Buffeting, of a magnitude and severity that is strong and
effective deterrent to further speed reduction; or
(3) The pitch control reaches the aft stop and no further increase
in pitch attitude occurs when the control is held full aft for a short
time before recovery is initiated.
(g) An aircraft exhibits unacceptable characteristics during
straight or turning flight decelerations if it is not always possible
to produce and to correct roll and yaw by unreversed use of aileron and
rudder controls, or abnormal nose-up pitching occurs.
5. Handling Characteristics at High Incidence
In lieu of Sec. Sec. 25.201 and 25.203, the following requirements
apply:
5.1 High Incidence Handling Demonstration
In lieu of Sec. 25.201:
(a) Maneuvers to the limit of the longitudinal control, in the
nose-up pitch, must be demonstrated in straight flight and in 30[deg]
banked turns with:
(1) The high incidence protection system operating normally;
(2) Initial power conditions of:
i. Power off (engine power or thrust at flight idle); and
ii. The power necessary to maintain level flight at 1.5
VSR1, where VSR1 is the reference stall speed
with flaps in approach position, the landing gear retracted, and
maximum landing weight;
(3) Flaps, landing gear, and deceleration devices in any likely
combination of positions;
(4) Representative weights within the range for which certification
is requested; and
(5) The airplane trimmed for straight flight at a speed selected by
the applicant, but not less than 1.13 V SR and not greater than 1.3
VSR.
(b) The following procedures must be used to show compliance in
non-icing and icing conditions:
(1) Starting at a speed sufficiently above the minimum steady
flight speed to ensure that a steady rate of speed reduction can be
established, apply the longitudinal control so that the speed reduction
does not exceed 1 knot per second until the control reaches the stop;
(2) The longitudinal control must be maintained at the stop until
the airplane has reached a stabilized flight condition and must then be
recovered by normal recovery techniques;
(3) Maneuvers with increased deceleration rates:
(i) In non-icing conditions, the requirements must also be met with
increased rates of entry to the incidence limit, up to the maximum
practical entry rate; and
(ii) In icing conditions, with the anti-ice system working
normally, the requirements must also be met with increased rates of
entry to the incidence limit, up to 3 knots per second; and
(4) Maneuver with ice accretion prior to operation of the normal
anti-ice system. With the ice accretion prior to operation of the
normal anti-ice system, the requirements must also be met in
deceleration at 1 knot per second. The deceleration must be continued
until one second after the activation of the tactile stall warning
system or three seconds after reaching full back stick, whichever
occurs first. A primary ice detection system must automatically
activate the ice protection.
5.2 Characteristics in High Incidence Maneuvers
In lieu of Sec. 25.203:
In icing and non-icing conditions:
(a) Throughout maneuvers with a rate of deceleration of not more
than 1 knot per second, both in straight flight and in 30[deg] banked
turns, the airplane's characteristics must be as follows:
(1) There must not be any abnormal nose-up pitching.
(2) There must not be any uncommanded nose-down pitching, which
would be indicative of stall. However, reasonable attitude changes
associated with stabilizing the incidence at Alpha limit as the
longitudinal control reaches the stop would be acceptable.
(3) There must not be any uncommanded lateral or directional motion
and the pilot must retain good lateral and directional control, by
conventional use of the controls, throughout the maneuver.
(4) The airplane must not exhibit buffeting of a magnitude and
severity that would act as a deterrent from completing the maneuver
specified in paragraph 5.1(a).
(b) In maneuvers with increased rates of deceleration, some
degradation of characteristics is acceptable, associated with a
transient excursion beyond the stabilized Alpha limit. However, the
airplane must not exhibit dangerous characteristics or characteristics
that would deter the pilot from holding the longitudinal control on the
stop for a period of time appropriate to the maneuver.
(c) It must always be possible to reduce incidence by conventional
use of the controls.
(d) The rate at which the airplane can be maneuvered from trim
speeds associated with scheduled operating speeds such as V2
and VREF up to Alpha limit must not be unduly damped or be
significantly slower than can be achieved on conventionally controlled
transport airplanes.
5.3 Characteristics Up to Maximum Lift Angle of Attack
Also in lieu of Sec. 25.201:
(a) In non-icing conditions:
Maneuvers with a rate of deceleration of not more than 1 knot per
second up to the angle of attack at which VCLmax was
obtained as defined in section 3, ``Minimum Steady Flight Speed and
Reference Stall Speed,'' must be demonstrated in straight flight and in
30[deg] banked turns in the following configurations:
(1) The high incidence protection deactivated or adjusted, at the
option of the applicant, to allow higher incidence than is possible
with the normal production system;
(2) Automatic thrust increase system inhibited (if applicable);
(3) Engines idling;
(4) Flaps and landing gear in any likely combination of positions;
and
(5) The airplane trimmed for straight flight at a speed selected by
the applicant, but not less than 1.13 VSR and not greater
than 1.3 VSR.
(b) In icing conditions:
Maneuvers with a rate of deceleration of not more than 1 knot per
second up to the maximum angle of attack reached during maneuvers from
paragraph 5.1(b)(3)(ii) must be demonstrated in straight flight with:
(1) The high incidence protection deactivated or adjusted, at the
option of the applicant, to allow higher incidence than is possible
with the normal production system;
(2) Automatic thrust increase system inhibited (if applicable);
(3) Engines idling;
(4) Flaps and landing gear in any likely combination of positions,
and
(5) The airplane trimmed for straight flight at a speed achievable
by the automatic trim system.
(c) During the maneuvers used to show compliance with paragraphs
(a) and (b) above, the airplane must not exhibit dangerous
characteristics, and it
[[Page 37811]]
must always be possible to reduce angle of attack by conventional use
of the controls. The pilot must retain good lateral and directional
control, by conventional use of the controls, throughout the maneuver.
6. Atmospheric Disturbances
Operation of the high incidence protection system must not
adversely affect aircraft control during expected levels of atmospheric
disturbances, nor impede the application of recovery procedures in case
of wind-shear. This must be demonstrated in non-icing and icing
conditions.
7. Proof of Compliance
In addition to the requirements of Sec. 25.21, the following
requirement applies:
(b) The flying qualities must be evaluated at the most unfavorable
center-of-gravity position.
8. Sections 25.145(a), 25.145(b)(6), and 25.1323(d)
The following requirements apply:
For Sec. 25.145(a), add ``Vmin'' in lieu of
``stall identification.''
For Sec. 25.145(b)(6), and ``Vmin'' in lieu of
``VSW.''
For Sec. 25.1323(d), add ``From 1.23 VSR to
Vmin . . .,'' in lieu of, ``1.23 VSR to the speed
at which stall warning begins . . .,'' and, ``. . . speeds below
Vmin . . .'' in lieu of, ``. . . speeds below stall
warning.''
Special Conditions Part II
Credit for Robust Envelope Protection in Icing Conditions
The following special conditions are in lieu of the specified
paragraphs of Sec. Sec. 25.103, 25.105, 25.107, 25.121, 25.123,
25.125, 25.143, and 25.207.
1. Define the stall speed as provided in these special conditions,
Part I, in lieu of Sec. 25.103.
2. In lieu of Sec. 25.105(a)(2)(i), the following requirement
applies:
(i) The V2 speed scheduled in non-icing conditions does
not provide the maneuvering capability specified in Sec. 25.143(h) for
the takeoff configuration, or
3. In lieu of Sec. 25.107(c) and (g), the following requirements
apply, with additional sections (c') and (g'):
Takeoff speeds:
(c) In non-icing conditions V2, in terms of calibrated
airspeed, must be selected by the applicant to provide at least the
gradient of climb required by Sec. 25.121(b) but may not be less
than--
(1) V2MIN;
(2) VR plus the speed increment attained (in accordance
with Sec. 25.111(c)(2)) before reaching a height of 35 feet above the
takeoff surface; and
(3) A speed that provides the maneuvering capability specified in
Sec. 25.143(h).
(c') In icing conditions with the ``takeoff ice'' accretion defined
in part 25, appendix C, V2 may not be less than--
(1) The V2 speed determined in non-icing conditions; and
(2) A speed that provides the maneuvering capability specified in
Sec. 25.143(h).
(g) In non-icing conditions, VFTO, in terms of
calibrated airspeed, must be selected by the applicant to provide at
least the gradient of climb required by Sec. 25.121(c), but may not be
less than--
(1) 1.18 VSR; and
(2) A speed that provides the maneuvering capability specified in
Sec. 25.143(h).
(g') In icing conditions with the ``final takeoff ice'' accretion
defined in part 25, appendix C, VFTO, may not be less than--
(1) The VFTO speed determined in non-icing conditions.
(2) A speed that provides the maneuvering capability specified in
Sec. 25.143(h).
4. In lieu of Sec. Sec. 25.121(b)(2)(ii)(A), 25.121(c)(2)(ii)(A),
and 25.121(d)(2)(ii), the following requirements apply:
In lieu of Sec. 25.121(b)(2)(ii)(A):
(A) The V2 speed scheduled in non-icing conditions does
not provide the maneuvering capability specified in Sec. 25.143(h) for
the takeoff configuration; or
In lieu of Sec. 25.121(c)(2)(ii)(A):
(A) The VFTO speed scheduled in non-icing conditions
does not provide the maneuvering capability specified in Sec.
25.143(h) for the en-route configuration; or
In lieu of Sec. 25.121(d)(2)(ii):
(d)(2) The requirements of subparagraph (d)(1) of this paragraph
must be met: (ii) In icing conditions with the approach ice accretion
defined in appendix C, in a configuration corresponding to the normal
all-engines-operating procedure in which Vmin1g for this
configuration does not exceed 110% of the Vmin1g for the
related all-engines-operating landing configuration in icing, with a
climb speed established with normal landing procedures, but not more
than 1.4 VSR (VSR determined in non-icing
conditions).
5. In lieu of Sec. 25.123(b)(2)(i), the following requirements
apply:
(i) The minimum en-route speed scheduled in non-icing conditions
does not provide the maneuvering capability specified in Sec.
25.143(h) for the en-route configuration, or
6. In lieu of Sec. Sec. 25.125(b)(2)(ii)(B) and
25.125(b)(2)(ii)(C), the following requirements apply:
(B) A speed that provides the maneuvering capability specified in
Sec. 25.143(h) with the landing ice accretion defined in part 25,
appendix C.
(C) 1.17 Vmin1g.
7. In lieu of Sec. 25.143(j)(1), the following requirement
applies:
(1) The airplane is controllable in a pull-up maneuver up to 1.5 g
load factor or lower if limited by angle of attack protection; and
8. In lieu of Sec. 25.207, Stall warning, to read as the
requirements defined in these special conditions Part I, Section 4.
Issued in Renton, Washington, on July 31, 2017.
Victor Wicklund,
Manager, Transport Standards Branch, Aircraft Certification Service.
[FR Doc. 2017-17072 Filed 8-11-17; 8:45 am]
BILLING CODE 4910-13-P