Special Conditions; Pilatus Aircraft Ltd.; Model PC-12/47E; Protection of Systems for High Intensity Radiated Fields (HIRF), 69574-69576 [E7-23837]
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69574
Federal Register / Vol. 72, No. 236 / Monday, December 10, 2007 / Rules and Regulations
levels in which civilian airplane system
installations must be capable of
operating safely are based on surveys
and analysis of existing radio frequency
emitters. These special conditions
require that the airplane be evaluated
under these energy levels for the
protection of the electronic system and
its associated wiring harness. These
external threat levels, which are lower
than previous required values, are
believed to represent the worst case to
which an airplane would be exposed in
the operating environment.
These special conditions require
qualification of systems that perform
critical functions, as installed in aircraft,
to the defined HIRF environment in
paragraph 1 or, as an option to a fixed
value using laboratory tests, in
paragraph 2, as follows:
(1) The applicant may demonstrate
that the operation and operational
capability of the installed electrical and
electronic systems that perform critical
functions are not adversely affected
when the aircraft is exposed to the HIRF
environment defined below:
Frequency
Field strength
(volts per meter)
Peak
10 kHz–100 kHz ...........
100 kHz–500 kHz .........
500 kHz–2 MHz ............
2 MHz–30 MHz .............
30 MHz–70 MHz ...........
70 MHz–100 MHz .........
100 MHz–200 MHz .......
200 MHz–400 MHz .......
400 MHz–700 MHz .......
700 MHz–1 GHz ...........
1 GHz–2 GHz ...............
2 GHz–4 GHz ...............
4 GHz–6 GHz ...............
6 GHz–8 GHz ...............
8 GHz–12 GHz .............
12 GHz–18 GHz ...........
18 GHz–40 GHz ...........
Average
50
50
50
100
50
50
100
100
700
700
2000
3000
3000
1000
3000
2000
600
50
50
50
100
50
50
100
100
50
100
200
200
200
200
300
200
200
mstockstill on PROD1PC66 with RULES
The field strengths are expressed in terms
of peak root-mean-square (rms) values.
or,
(2) The applicant may demonstrate by
a system test and analysis that the
electrical and electronic systems that
perform critical functions can withstand
a minimum threat of 100 volts per
meter, electrical field strength, from 10
kHz to 18 GHz. When using this test to
show compliance with the HIRF
requirements, no credit is given for
signal attenuation due to installation.
A preliminary hazard analysis must
be performed by the applicant, for
approval by the FAA, to identify either
electrical or electronic systems that
perform critical functions. The term
‘‘critical’’ means those functions, whose
failure would contribute to, or cause, a
VerDate Aug<31>2005
16:20 Dec 07, 2007
Jkt 214001
failure condition that would prevent the
continued safe flight and landing of the
airplane. The systems identified by the
hazard analysis that perform critical
functions are candidates for the
application of HIRF requirements. A
system may perform both critical and
non-critical functions. Primary
electronic flight display systems, and
their associated components, perform
critical functions such as attitude,
altitude, and airspeed indication. The
HIRF requirements apply only to critical
functions.
Compliance with HIRF requirements
may be demonstrated by tests, analysis,
models, similarity with existing
systems, or any combination of these.
Service experience alone is not
acceptable since normal flight
operations may not include an exposure
to the HIRF environment. Reliance on a
system with similar design features for
redundancy as a means of protection
against the effects of external HIRF is
generally insufficient since all elements
of a redundant system are likely to be
exposed to the fields concurrently.
Applicability
As discussed above, these special
conditions are applicable to the
Hondajet HA–420 project. Should
Honda Aircraft Company apply at a later
date for a supplemental type certificate
to modify any other model on the same
type certificate to incorporate the same
novel or unusual design feature, the
special conditions would apply to that
model as well under the provisions of
§ 21.101.
Conclusion
This action affects only certain novel
or unusual design features 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 these features on the
airplane.
The substance of these special
conditions has been subjected 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. For this reason, and
because a delay would significantly
affect the certification of the airplane,
which is imminent, the FAA has
determined that prior public notice and
comment are unnecessary and
impracticable, and good cause exists for
adopting these special conditions upon
issuance. The FAA is requesting
comments to allow interested persons to
submit views that may not have been
PO 00000
Frm 00006
Fmt 4700
Sfmt 4700
submitted in response to the prior
opportunities for comment described
above.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and
symbols.
Citation
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and
44701; 14 CFR 21.16 and 21.17 and 14 CFR
11.38 and 11.19.
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 Hondajet HA–420
manufactured by Honda Aircraft
Company.
1. Protection of Electrical and
Electronic Systems from High Intensity
Radiated Fields (HIRF). Each system
that performs critical functions must be
designed and installed to ensure that the
operations, and operational capabilities
of these systems to perform critical
functions, are not adversely affected
when the airplane is exposed to high
intensity radiated electromagnetic fields
external to the airplane.
2. For the purpose of these special
conditions, the following definition
applies: Critical Functions: Functions
whose failure would contribute to, or
cause, a failure condition that would
prevent the continued safe flight and
landing of the airplane.
Issued in Kansas City, Missouri on
November 30, 2007.
Patrick R. Mullen,
Acting Manager, Small Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E7–23831 Filed 12–7–07; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE276, Special Condition 23–
216–SC]
Special Conditions; Pilatus Aircraft
Ltd.; Model PC–12/47E; Protection of
Systems for High Intensity Radiated
Fields (HIRF)
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions; request
for comments.
AGENCY:
E:\FR\FM\10DER1.SGM
10DER1
Federal Register / Vol. 72, No. 236 / Monday, December 10, 2007 / Rules and Regulations
mstockstill on PROD1PC66 with RULES
SUMMARY: These special conditions are
issued to Pilatus Aircraft Ltd., for an
Amended Type Certificate for the Model
PC–12/47E airplane. This airplane will
have novel and unusual design features
when compared to the state of
technology envisaged in the applicable
airworthiness standards. These novel
and unusual design features include the
installation of electronic flight
instrument system (EFIS) displays
Model APEX manufactured by
Honeywell for which the applicable
regulations do not contain adequate or
appropriate airworthiness standards for
the protection of these systems from the
effects of high intensity radiated fields
(HIRF). These special conditions
contain the additional safety standards
that the Administrator considers
necessary to establish a level of safety
equivalent to the airworthiness
standards applicable to these airplanes.
DATES: The effective date of these
special conditions is November 30,
2007. Comments must be received on or
before January 9, 2008.
ADDRESSES: Comments may be mailed
in duplicate to: Federal Aviation
Administration, Regional Counsel,
ACE–7, Attention: Rules Docket Clerk,
Docket No. CE276, Room 506, 901
Locust, Kansas City, Missouri 64106. All
comments must be marked: Docket No.
CE276. Comments may be inspected in
the Rules Docket weekdays, except
Federal holidays, between 7:30 a.m. and
4 p.m.
FOR FURTHER INFORMATION CONTACT: Jim
Brady, Aerospace Engineer, Standards
Office (ACE–111), Small Airplane
Directorate, Aircraft Certification
Service, Federal Aviation
Administration, 901 Locust, Room 301,
Kansas City, Missouri 64106; telephone
(816) 329–4132.
SUPPLEMENTARY INFORMATION: The FAA
has determined that notice and
opportunity for prior public comment
hereon are impracticable because these
procedures would significantly delay
issuance of the approval design and
thus delivery of the affected aircraft. In
addition, 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, therefore, finds that
good cause exists for making these
special conditions effective upon
issuance.
Comments Invited
Interested persons are invited to
submit such written data, views, or
arguments as they may desire.
Communications should identify the
regulatory docket or notice number and
VerDate Aug<31>2005
16:20 Dec 07, 2007
Jkt 214001
be submitted in duplicate to the address
specified above. All communications
received on or before the closing date
for comments will be considered by the
Administrator. The special conditions
may be changed in light of the
comments received. All comments
received will be available in the Rules
Docket for examination by interested
persons, both before and after the
closing date for comments. A report
summarizing each substantive public
contact with FAA personnel concerning
this rulemaking will be filed in the
docket. Commenters wishing the FAA to
acknowledge receipt of their comments
submitted in response to this notice
must include a self-addressed, stamped
postcard on which the following
statement is made: ‘‘Comments to
Docket No. CE276.’’ The postcard will
be date stamped and returned to the
commenter.
Background
On Nov. 10, 2003, Pilatus Aircraft
Ltd., made an application to the FAA for
a new Amended Type Certificate for the
project airplane. The PC–12/47 is
currently approved under TC No.
A78EU. The proposed modification
incorporates a novel or unusual design
feature, such as digital avionics
consisting of an EFIS that is vulnerable
to HIRF external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR part
21, § 21.101, Pilatus Aircraft Ltd. must
show that the project aircraft meets the
following provisions, or the applicable
regulations in effect on the date of
application for the change to the project:
14 CFR 21.29, 21.183(c) and 14 CFR part
23, Normal Category, effective February
4, 1991, including Amendments 23–1
through 23–42 and § 23.1305c)3) of
Amendment 23–43 and § 23.1507 of
Amendment 23–45 and § 23.1311 of
Amendment 23–49 and 14 CFR part 36,
effective November 18, 1969, including
Amendments 36–1 through amendment
in effect at the time of U.S. Type
Certification, and 14 CFR part 34,
effective September 10, 1990, and
Equivalent Level of Safety, a) ACE–94–
8 of June 21, 1994, Spin demonstration,
FAR 23.221 a)2), b) Cabin pressure
indicator, FAR 23.841b) 6), Section
611(b) of the FAA Act of 1958,
Certification Maintenance Requirement
(CMR), manual pitch trim system
annunciation, Special Conditions, High
Energy Radiated Electromagnetic Fields,
(HIRF), 23–ACE–46, effective date May
29, 1990, Approved for Flight Into
Known Icing as applicable, and
§ 23.1301 of Amendment 23–20;
§§ 23.1309, 23.1311, and 23.1321 of
PO 00000
Frm 00007
Fmt 4700
Sfmt 4700
69575
Amendment 23–49; and § 23.1322 of
Amendment 23–43; exemptions, if any;
and the special conditions adopted by
this rulemaking action.
Discussion
If the Administrator finds that the
applicable airworthiness standards do
not contain adequate or appropriate
safety standards because of novel or
unusual design features of an airplane,
special conditions are prescribed under
the provisions of § 21.16.
Special conditions, as appropriate, as
defined in § 11.19, are issued in
accordance with § 11.38 after public
notice and become part of the type
certification basis in accordance with
§ 21.101(b)(2).
Special conditions are initially
applicable to the model for which they
are issued. Should the applicant apply
for a supplemental type certificate to
modify any other model already
included on the same type certificate to
incorporate the same novel or unusual
design feature, the special conditions
would also apply to the other model
under the provisions of § 21.101.
Novel or Unusual Design Features
Pilatus Aircraft Ltd. plans to
incorporate certain novel and unusual
design features into an airplane for
which the airworthiness standards do
not contain adequate or appropriate
safety standards for protection from the
effects of HIRF. These features include
EFIS, which are susceptible to the HIRF
environment, that were not envisaged
by the existing regulations for this type
of airplane.
Protection of Systems from High
Intensity Radiated Fields (HIRF): Recent
advances in technology have given rise
to the application in aircraft designs of
advanced electrical and electronic
systems that perform functions required
for continued safe flight and landing.
Due to the use of sensitive solid state
advanced components in analog and
digital electronics circuits, these
advanced systems are readily responsive
to the transient effects of induced
electrical current and voltage caused by
the HIRF. The HIRF can degrade
electronic systems performance by
damaging components or upsetting
system functions.
Furthermore, the HIRF environment
has undergone a transformation that was
not foreseen when the current
requirements were developed. Higher
energy levels are radiated from
transmitters that are used for radar,
radio, and television. Also, the number
of transmitters has increased
significantly. There is also uncertainty
concerning the effectiveness of airframe
E:\FR\FM\10DER1.SGM
10DER1
69576
Federal Register / Vol. 72, No. 236 / Monday, December 10, 2007 / Rules and Regulations
shielding for HIRF. Furthermore,
coupling to cockpit-installed equipment
through the cockpit window apertures is
undefined.
The combined effect of the
technological advances in airplane
design and the changing environment
has resulted in an increased level of
vulnerability of electrical and electronic
systems required for the continued safe
flight and landing of the airplane.
Effective measures against the effects of
exposure to HIRF must be provided by
the design and installation of these
systems. The accepted maximum energy
levels in which civilian airplane system
installations must be capable of
operating safely are based on surveys
and analysis of existing radio frequency
emitters. These special conditions
require that the airplane be evaluated
under these energy levels for the
protection of the electronic system and
its associated wiring harness. These
external threat levels, which are lower
than previous required values, are
believed to represent the worst case to
which an airplane would be exposed in
the operating environment.
These special conditions require
qualification of systems that perform
critical functions, as installed in aircraft,
to the defined HIRF environment in
paragraph 1 or, as an option to a fixed
value using laboratory tests, in
paragraph 2, as follows:
(1) The applicant may demonstrate
that the operation and operational
capability of the installed electrical and
electronic systems that perform critical
functions are not adversely affected
when the aircraft is exposed to the HIRF
environment defined below:
Frequency
Field strength
(volts per meter)
Peak
mstockstill on PROD1PC66 with RULES
10 kHz–100 kHz ...........
100 kHz–500 kHz .........
500 kHz–2 MHz ............
2 MHz–30 MHz .............
30 MHz–70 MHz ...........
70 MHz–100 MHz .........
100 MHz–200 MHz .......
200 MHz–400 MHz .......
400 MHz–700 MHz .......
700 MHz–1 GHz ...........
1 GHz–2 GHz ...............
2 GHz–4 GHz ...............
4 GHz–6 GHz ...............
6 GHz–8 GHz ...............
8 GHz–12 GHz .............
12 GHz–18 GHz ...........
18 GHz–40 GHz ...........
Average
50
50
50
100
50
50
100
100
700
700
2000
3000
3000
1000
3000
2000
600
50
50
50
100
50
50
100
100
50
100
200
200
200
200
300
200
200
The field strengths are expressed in terms
of peak root-mean-square (rms) values.
or,
(2) The applicant may demonstrate by
a system test and analysis that the
VerDate Aug<31>2005
16:20 Dec 07, 2007
Jkt 214001
electrical and electronic systems that
perform critical functions can withstand
a minimum threat of 100 volts per
meter, electrical field strength, from 10
kHz to 18 GHz. When using this test to
show compliance with the HIRF
requirements, no credit is given for
signal attenuation due to installation.
A preliminary hazard analysis must
be performed by the applicant, for
approval by the FAA, to identify either
electrical or electronic systems that
perform critical functions. The term
‘‘critical’’ means those functions whose
failure would contribute to, or cause, a
failure condition that would prevent the
continued safe flight and landing of the
airplane. The systems identified by the
hazard analysis that perform critical
functions are candidates for the
application of HIRF requirements. A
system may perform both critical and
non-critical functions. Primary
electronic flight display systems, and
their associated components, perform
critical functions such as attitude,
altitude, and airspeed indication. The
HIRF requirements apply only to critical
functions.
Compliance with HIRF requirements
may be demonstrated by tests, analysis,
models, similarity with existing
systems, or any combination of these.
Service experience alone is not
acceptable since normal flight
operations may not include an exposure
to the HIRF environment. Reliance on a
system with similar design features for
redundancy as a means of protection
against the effects of external HIRF is
generally insufficient since all elements
of a redundant system are likely to be
exposed to the fields concurrently.
Applicability
As discussed above, these special
conditions are applicable to the PC–12/
47E. Should Pilatus Aircraft Ltd. apply
at a later date for a supplemental type
certificate to modify any other model on
the same type certificate to incorporate
the same novel or unusual design
feature, the special conditions would
apply to that model as well under the
provisions of § 21.101.
Conclusion
This action affects only certain novel
or unusual design features 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 these features on the
airplane.
The substance of these special
conditions has been subjected to the
notice and comment period in several
prior instances and has been derived
without substantive change from those
PO 00000
Frm 00008
Fmt 4700
Sfmt 4700
previously issued. It is unlikely that
prior public comment would result in a
significant change from the substance
contained herein. For this reason, and
because a delay would significantly
affect the certification of the airplane,
which is imminent, the FAA has
determined that prior public notice and
comment are unnecessary and
impracticable, and good cause exists for
adopting these special conditions upon
issuance. 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.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and
symbols.
Citation
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and
44701; 14 CFR 21.16 and 21.101; and 14 CFR
11.38 and 11.19.
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 PC–12/47E Project
airplane modified by Pilatus Aircraft
Ltd. to add an EFIS.
1. Protection of Electrical and
Electronic Systems from High Intensity
Radiated Fields (HIRF). Each system
that performs critical functions must be
designed and installed to ensure that the
operations, and operational capabilities
of these systems to perform critical
functions, are not adversely affected
when the airplane is exposed to high
intensity radiated electromagnetic fields
external to the airplane.
2. For the purpose of these special
conditions, the following definition
applies: Critical Functions: Functions
whose failure would contribute to, or
cause, a failure condition that would
prevent the continued safe flight and
landing of the airplane.
Issued in Kansas City, Missouri on
November 30, 2007.
Patrick R. Mullen,
Acting Manager, Small Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E7–23837 Filed 12–7–07; 8:45 am]
BILLING CODE 4910–13–P
E:\FR\FM\10DER1.SGM
10DER1
]]>Agencies
[Federal Register Volume 72, Number 236 (Monday, December 10, 2007)]
[Rules and Regulations]
[Pages 69574-69576]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-23837]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE276, Special Condition 23-216-SC]
Special Conditions; Pilatus Aircraft Ltd.; Model PC-12/47E;
Protection of Systems for High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
[[Page 69575]]
SUMMARY: These special conditions are issued to Pilatus Aircraft Ltd.,
for an Amended Type Certificate for the Model PC-12/47E airplane. This
airplane will have novel and unusual design features when compared to
the state of technology envisaged in the applicable airworthiness
standards. These novel and unusual design features include the
installation of electronic flight instrument system (EFIS) displays
Model APEX manufactured by Honeywell for which the applicable
regulations do not contain adequate or appropriate airworthiness
standards for the protection of these systems from the effects of high
intensity radiated fields (HIRF). These special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to the airworthiness
standards applicable to these airplanes.
DATES: The effective date of these special conditions is November 30,
2007. Comments must be received on or before January 9, 2008.
ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk,
Docket No. CE276, Room 506, 901 Locust, Kansas City, Missouri 64106.
All comments must be marked: Docket No. CE276. Comments may be
inspected in the Rules Docket weekdays, except Federal holidays,
between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Jim Brady, Aerospace Engineer,
Standards Office (ACE-111), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, 901 Locust,
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4132.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice and
opportunity for prior public comment hereon are impracticable because
these procedures would significantly delay issuance of the approval
design and thus delivery of the affected aircraft. In addition, 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, therefore, finds that good cause exists for making
these special conditions effective upon issuance.
Comments Invited
Interested persons are invited to submit such written data, views,
or arguments as they may desire. Communications should identify the
regulatory docket or notice number and be submitted in duplicate to the
address specified above. All communications received on or before the
closing date for comments will be considered by the Administrator. The
special conditions may be changed in light of the comments received.
All comments received will be available in the Rules Docket for
examination by interested persons, both before and after the closing
date for comments. A report summarizing each substantive public contact
with FAA personnel concerning this rulemaking will be filed in the
docket. Commenters wishing the FAA to acknowledge receipt of their
comments submitted in response to this notice must include a self-
addressed, stamped postcard on which the following statement is made:
``Comments to Docket No. CE276.'' The postcard will be date stamped and
returned to the commenter.
Background
On Nov. 10, 2003, Pilatus Aircraft Ltd., made an application to the
FAA for a new Amended Type Certificate for the project airplane. The
PC-12/47 is currently approved under TC No. A78EU. The proposed
modification incorporates a novel or unusual design feature, such as
digital avionics consisting of an EFIS that is vulnerable to HIRF
external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR part 21, Sec. 21.101, Pilatus
Aircraft Ltd. must show that the project aircraft meets the following
provisions, or the applicable regulations in effect on the date of
application for the change to the project: 14 CFR 21.29, 21.183(c) and
14 CFR part 23, Normal Category, effective February 4, 1991, including
Amendments 23-1 through 23-42 and Sec. 23.1305c)3) of Amendment 23-43
and Sec. 23.1507 of Amendment 23-45 and Sec. 23.1311 of Amendment 23-
49 and 14 CFR part 36, effective November 18, 1969, including
Amendments 36-1 through amendment in effect at the time of U.S. Type
Certification, and 14 CFR part 34, effective September 10, 1990, and
Equivalent Level of Safety, a) ACE-94-8 of June 21, 1994, Spin
demonstration, FAR 23.221 a)2), b) Cabin pressure indicator, FAR
23.841b) 6), Section 611(b) of the FAA Act of 1958, Certification
Maintenance Requirement (CMR), manual pitch trim system annunciation,
Special Conditions, High Energy Radiated Electromagnetic Fields,
(HIRF), 23-ACE-46, effective date May 29, 1990, Approved for Flight
Into Known Icing as applicable, and Sec. 23.1301 of Amendment 23-20;
Sec. Sec. 23.1309, 23.1311, and 23.1321 of Amendment 23-49; and Sec.
23.1322 of Amendment 23-43; exemptions, if any; and the special
conditions adopted by this rulemaking action.
Discussion
If the Administrator finds that the applicable airworthiness
standards do not contain adequate or appropriate safety standards
because of novel or unusual design features of an airplane, special
conditions are prescribed under the provisions of Sec. 21.16.
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in accordance with Sec. 11.38 after public notice and become
part of the type certification basis in accordance with Sec.
21.101(b)(2).
Special conditions are initially applicable to the model for which
they are issued. Should the applicant apply for a supplemental type
certificate to modify any other model already included on the same type
certificate to incorporate the same novel or unusual design feature,
the special conditions would also apply to the other model under the
provisions of Sec. 21.101.
Novel or Unusual Design Features
Pilatus Aircraft Ltd. plans to incorporate certain novel and
unusual design features into an airplane for which the airworthiness
standards do not contain adequate or appropriate safety standards for
protection from the effects of HIRF. These features include EFIS, which
are susceptible to the HIRF environment, that were not envisaged by the
existing regulations for this type of airplane.
Protection of Systems from High Intensity Radiated Fields (HIRF):
Recent advances in technology have given rise to the application in
aircraft designs of advanced electrical and electronic systems that
perform functions required for continued safe flight and landing. Due
to the use of sensitive solid state advanced components in analog and
digital electronics circuits, these advanced systems are readily
responsive to the transient effects of induced electrical current and
voltage caused by the HIRF. The HIRF can degrade electronic systems
performance by damaging components or upsetting system functions.
Furthermore, the HIRF environment has undergone a transformation
that was not foreseen when the current requirements were developed.
Higher energy levels are radiated from transmitters that are used for
radar, radio, and television. Also, the number of transmitters has
increased significantly. There is also uncertainty concerning the
effectiveness of airframe
[[Page 69576]]
shielding for HIRF. Furthermore, coupling to cockpit-installed
equipment through the cockpit window apertures is undefined.
The combined effect of the technological advances in airplane
design and the changing environment has resulted in an increased level
of vulnerability of electrical and electronic systems required for the
continued safe flight and landing of the airplane. Effective measures
against the effects of exposure to HIRF must be provided by the design
and installation of these systems. The accepted maximum energy levels
in which civilian airplane system installations must be capable of
operating safely are based on surveys and analysis of existing radio
frequency emitters. These special conditions require that the airplane
be evaluated under these energy levels for the protection of the
electronic system and its associated wiring harness. These external
threat levels, which are lower than previous required values, are
believed to represent the worst case to which an airplane would be
exposed in the operating environment.
These special conditions require qualification of systems that
perform critical functions, as installed in aircraft, to the defined
HIRF environment in paragraph 1 or, as an option to a fixed value using
laboratory tests, in paragraph 2, as follows:
(1) The applicant may demonstrate that the operation and
operational capability of the installed electrical and electronic
systems that perform critical functions are not adversely affected when
the aircraft is exposed to the HIRF environment defined below:
------------------------------------------------------------------------
Field strength
(volts per meter)
Frequency -------------------
Peak Average
------------------------------------------------------------------------
10 kHz-100 kHz...................................... 50 50
100 kHz-500 kHz..................................... 50 50
500 kHz-2 MHz....................................... 50 50
2 MHz-30 MHz........................................ 100 100
30 MHz-70 MHz....................................... 50 50
70 MHz-100 MHz...................................... 50 50
100 MHz-200 MHz..................................... 100 100
200 MHz-400 MHz..................................... 100 100
400 MHz-700 MHz..................................... 700 50
700 MHz-1 GHz....................................... 700 100
1 GHz-2 GHz......................................... 2000 200
2 GHz-4 GHz......................................... 3000 200
4 GHz-6 GHz......................................... 3000 200
6 GHz-8 GHz......................................... 1000 200
8 GHz-12 GHz........................................ 3000 300
12 GHz-18 GHz....................................... 2000 200
18 GHz-40 GHz....................................... 600 200
------------------------------------------------------------------------
The field strengths are expressed in terms of peak root-mean-square
(rms) values.
or,
(2) The applicant may demonstrate by a system test and analysis
that the electrical and electronic systems that perform critical
functions can withstand a minimum threat of 100 volts per meter,
electrical field strength, from 10 kHz to 18 GHz. When using this test
to show compliance with the HIRF requirements, no credit is given for
signal attenuation due to installation.
A preliminary hazard analysis must be performed by the applicant,
for approval by the FAA, to identify either electrical or electronic
systems that perform critical functions. The term ``critical'' means
those functions whose failure would contribute to, or cause, a failure
condition that would prevent the continued safe flight and landing of
the airplane. The systems identified by the hazard analysis that
perform critical functions are candidates for the application of HIRF
requirements. A system may perform both critical and non-critical
functions. Primary electronic flight display systems, and their
associated components, perform critical functions such as attitude,
altitude, and airspeed indication. The HIRF requirements apply only to
critical functions.
Compliance with HIRF requirements may be demonstrated by tests,
analysis, models, similarity with existing systems, or any combination
of these. Service experience alone is not acceptable since normal
flight operations may not include an exposure to the HIRF environment.
Reliance on a system with similar design features for redundancy as a
means of protection against the effects of external HIRF is generally
insufficient since all elements of a redundant system are likely to be
exposed to the fields concurrently.
Applicability
As discussed above, these special conditions are applicable to the
PC-12/47E. Should Pilatus Aircraft Ltd. apply at a later date for a
supplemental type certificate to modify any other model on the same
type certificate to incorporate the same novel or unusual design
feature, the special conditions would apply to that model as well under
the provisions of Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
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 these
features on the airplane.
The substance of these special conditions has been subjected 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. For this reason, and because a
delay would significantly affect the certification of the airplane,
which is imminent, the FAA has determined that prior public notice and
comment are unnecessary and impracticable, and good cause exists for
adopting these special conditions upon issuance. 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.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and
21.101; and 14 CFR 11.38 and 11.19.
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 PC-12/47E Project airplane modified by
Pilatus Aircraft Ltd. to add an EFIS.
1. Protection of Electrical and Electronic Systems from High
Intensity Radiated Fields (HIRF). Each system that performs critical
functions must be designed and installed to ensure that the operations,
and operational capabilities of these systems to perform critical
functions, are not adversely affected when the airplane is exposed to
high intensity radiated electromagnetic fields external to the
airplane.
2. For the purpose of these special conditions, the following
definition applies: Critical Functions: Functions whose failure would
contribute to, or cause, a failure condition that would prevent the
continued safe flight and landing of the airplane.
Issued in Kansas City, Missouri on November 30, 2007.
Patrick R. Mullen,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-23837 Filed 12-7-07; 8:45 am]
BILLING CODE 4910-13-P
