Special Conditions: Raytheon Model BH125 Series 400A and 600A Airplanes; High Intensity Radiated Fields (HIRF), 57728-57730 [05-19859]
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Federal Register / Vol. 70, No. 191 / Tuesday, October 4, 2005 / Rules and Regulations
electrical systems to HIRF must be
established.
It is not possible to precisely define
the HIRF to which the airplane will be
exposed in service. There is also
uncertainty concerning the effectiveness
of airframe shielding for HIRF.
Furthermore, coupling of
electromagnetic energy to cockpitinstalled equipment through the cockpit
window apertures is undefined. Based
on surveys and analysis of existing HIRF
emitters, an adequate level of protection
exists when compliance with the HIRF
protection special condition is shown
with either paragraph 1 or 2 below:
1. A minimum threat of 100 volts rms
(root-mean-square) per meter electric
field strength from 10 KHz to 18 GHz.
a. The threat must be applied to the
system elements and their associated
wiring harnesses without the benefit of
airframe shielding.
b. Demonstration of this level of
protection is established through system
tests and analysis.
2. A threat external to the airframe of
the field strengths indicated in the
following table for the frequency ranges
indicated. Both peak and average field
strength components from the table are
to be demonstrated.
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
The field strengths are expressed in terms
of peak of the root-mean-square (rms) over
the complete modulation period.
The threat levels identified above are
the result of an FAA review of existing
studies on the subject of HIRF, in light
of the ongoing work of the
Electromagnetic Effects Harmonization
Working Group of the Aviation
Rulemaking Advisory Committee.
Applicability
As discussed above, these special
conditions are applicable to Boeing
Model 720B airplane, modified by
Flight Test Associates, Inc. Should
VerDate Aug<31>2005
16:33 Oct 03, 2005
Jkt 208002
Flight Test Associates, Inc., 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 as
under the provisions of 14 CFR 21.101.
Conclusion
This action affects only certain design
features on the Boeing Model 720B
airplane modified by Flight Test
Associates, Inc. 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 the special
conditions for these airplanes has been
subjected to the notice and comment
procedure in several prior instances and
has been derived without substantive
change from those previously issued.
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
immediately. 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 25
Aircraft, Aviation safety, Reporting
and record keeping 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
supplemental type certification basis for
the Boeing Model 720B airplane,
modified by Flight Test Associates, Inc:
1. Protection from Unwanted Effects
of High-Intensity Radiated Fields
(HIRF). Each electrical and electronic
system that performs critical functions
must be designed and installed to
ensure that the operation and
operational capability of these systems
to perform critical functions are not
adversely affected when the airplane is
exposed to high intensity radiated
fields.
2. For the purpose of these special
conditions, the following definition
applies:
Critical Functions: Functions whose
failure would contribute to or cause a
PO 00000
Frm 00004
Fmt 4700
Sfmt 4700
failure condition that would prevent the
continued safe flight and landing of the
airplane.
Issued in Renton, Washington.
Kalene C. Yanamura,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 05–19858 Filed 10–3–05; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM328, Special Conditions No.
25–298–SC]
Special Conditions: Raytheon Model
BH125 Series 400A and 600A
Airplanes; High Intensity Radiated
Fields (HIRF)
Federal Aviation
Administration (FAA) DOT.
ACTION: Final special conditions; request
for comments.
AGENCY:
SUMMARY: These special conditions are
issued for Raytheon Model BH125
Series 400A and 600A airplanes. These
airplanes will have novel and unusual
design features when compared to the
state of technology envisioned in the
airworthiness standards for transport
category airplanes. The modification
incorporates the installation of dual
Honeywell Model AM–250 digital
altimeters. The applicable airworthiness
regulations do not contain adequate or
appropriate safety 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 that provided by the
existing airworthiness standards.
DATES: The effective date of these
special conditions is September 12,
2005. Comments must be received on or
before November 3, 2005.
ADDRESSES: Comments on these special
conditions may be mailed in duplicate
to: Federal Aviation Administration,
Transport Airplane Directorate, Attn:
Rules Docket (ANM–113), Docket No.
NM328, 1601 Lind Avenue SW.,
Renton, Washington, 98055–4056; or
delivered in duplicate to the Transport
Airplane Directorate at the above
address. All comments must be marked:
Docket No. NM328. Comments may be
inspected in the Rules Docket
weekdays, except Federal holidays,
between 7:30 a.m. and 4 p.m.
E:\FR\FM\04OCR1.SGM
04OCR1
Federal Register / Vol. 70, No. 191 / Tuesday, October 4, 2005 / Rules and Regulations
Mr.
Greg Dunn, FAA, Airplane & Flight
Crew Interface Branch, ANM–111,
Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98055–4056;
telephone (425) 227–2799; facsimile
(425) 227–1320.
SUPPLEMENTARY INFORMATION:
FOR FURTHER INFORMATION CONTACT:
Comments Invited
The FAA has determined that notice
and opportunity for prior public
comment hereon is unnecessary, as 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;
however, the FAA invites interested
persons to participate in this rulemaking
by submitting 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 ask that
you send us two copies of written
comments.
We will file in the docket all
comments we receive, as well as a
report summarizing each substantive
public contact with FAA personnel
concerning these special conditions.
The docket is available for public
inspection before and after the comment
closing date. If you wish to review the
docket in person, go to the address in
the ADDRESSES section of this preamble
between 7:30 a.m., and 4 p.m., Monday
through Friday, except Federal holidays.
We will consider all comments we
receive on or before the closing date for
comments. We will consider comments
filed late if it is possible to do so
without incurring expense or delay. We
may change these special conditions in
light of the comments received.
If you want the FAA to acknowledge
receipt of your comments on these
special conditions, include with your
comments a pre-addressed, stamped
postcard on which the docket number
appears. We will stamp the date on the
postcard and mail it back to you.
Background
On February 17, 2005, Flight Test
Associates, Inc., of Mojave, California,
applied to the FAA, Los Angeles
Aircraft Certification Office for a
supplemental type certificate (STC) to
modify Raytheon Model BH125 Series
400A and 600A airplanes. The proposed
modification incorporates the
installation of dual Honeywell Model
AM–250 digital altimeters as primary
VerDate Aug<31>2005
16:33 Oct 03, 2005
Jkt 208002
57729
instruments. The information presented
is flight critical. The altimeters installed
in the airplanes have the potential to be
vulnerable to high-intensity radiated
fields (HIRF) external to the airplanes.
adequate or appropriate safety standards
for the protection of this equipment
from the adverse effects of HIRF.
Accordingly, this system is considered
to be a novel or unusual design feature.
Type Certification Basis
Under the provisions of 14 CFR
21.101, Flight Test Associates, Inc.,
must show that the airplanes as
changed, continues to meet the
applicable provisions of the regulations
incorporated by reference in Type
Certificate No. A3EU, or the applicable
regulations in effect on the date of
application for the change. The
regulations incorporated by reference in
the type certificate are commonly
referred to as the ‘‘original type
certification basis.’’
The regulations incorporated by
reference in Type Certificate No. A3EU
include Civil Aeronautics Manual 4b, as
amended by Amendments 4b–1 through
4b–11.
If the Administrator finds that the
applicable airworthiness regulations
(i.e., part 25, as amended) do not
contain adequate or appropriate safety
standards for the modified Raytheon
Model BH125 Series 400A and 600A
airplanes, because of a novel or unusual
design feature, special conditions are
prescribed under the provisions of
§ 21.16.
In addition to the applicable
airworthiness regulations and special
conditions, the Raytheon Model BH125
Series 400A and 600A airplanes must
comply with the fuel vent and exhaust
emission requirements of 14 CFR part
24 and the noise certification
requirements of 14 CFR part 36.
Special conditions, as defined in 14
CFR 11.19, are issued in accordance
with § 11.38 and become part of the type
certification basis in accordance with
§ 21.101.
Special conditions are initially
applicable to the model for which they
are issued. Should Flight Test
Associates, Inc., apply at a later date for
an STC to modify any other model
included on the same type certificate to
incorporate the same novel or unusual
design feature, these special conditions
would also apply to the other model
under the provisions of § 21.101.
Discussion
Novel or Unusual Design Features
As noted earlier, the Raytheon Model
BH125 Series 400A and 600A airplanes
modified by Flight Test Associates, Inc.,
will incorporate new dual primary
altimeters that will perform critical
functions. These systems may be
vulnerable to HIRF external to the
airplane. The current airworthiness
standards of part 25 do not contain
PO 00000
Frm 00005
Fmt 4700
Sfmt 4700
There is no specific regulation that
addresses protection requirements for
electrical and electronic systems from
HIRF. Increased power levels from
ground-based radio transmitters and the
growing use of sensitive avionics/
electronics and electrical systems to
command and control airplanes have
made it necessary to provide adequate
protection.
To ensure that a level of safety is
achieved equivalent to that intended by
the regulations incorporated by
reference, special conditions are needed
for the Raytheon Model BH125 Series
400A and 600A airplanes. These special
conditions require that new primary
altimeters that perform critical functions
be designed and installed to preclude
component damage and interruption of
function due to both the direct and
indirect effects of HIRF.
High-Intensity Radiated Fields (HIRF)
With the trend toward increased
power levels from ground-based
transmitters, plus the advent of space
and satellite communications coupled
with electronic command and control of
the airplane, the immunity of critical
digital avionics/electronics and
electrical systems to HIRF must be
established.
It is not possible to precisely define
the HIRF to which the airplane will be
exposed in service. There is also
uncertainty concerning the effectiveness
of airframe shielding for HIRF.
Furthermore, coupling of
electromagnetic energy to cockpitinstalled equipment through the cockpit
window apertures is undefined. Based
on surveys and analysis of existing HIRF
emitters, an adequate level of protection
exists when compliance with the HIRF
protection special condition is shown
with either paragraph 1 or 2 below:
1. A minimum threat of 100 volts rms
(root-mean-square) per meter electric
field strength from 10 KHz to 18 GHz.
a. The threat must be applied to the
system elements and their associated
wiring harnesses without the benefit of
airframe shielding.
b. Demonstration of this level of
protection is established through system
tests and analysis.
2. A threat external to the airframe of
the field strengths indicated in the
following table for the frequency ranges
indicated. Both peak and average field
E:\FR\FM\04OCR1.SGM
04OCR1
57730
Federal Register / Vol. 70, No. 191 / Tuesday, October 4, 2005 / Rules and Regulations
strength components from the table are
to be demonstrated.
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
The field strengths are expressed in terms
of peak of the root-mean-square (rms) over
the complete modulation period.
The threat levels identified above are
the result of an FAA review of existing
studies on the subject of HIRF, in light
of the ongoing work of the
Electromagnetic Effects Harmonization
Working Group of the Aviation
Rulemaking Advisory Committee.
Applicability
As discussed above, these special
conditions are applicable to Raytheon
Model BH125 Series 400A and 600A
airplanes, modified by Flight Test
Associates, Inc. Should Flight Test
Associates, Inc., 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 as under the
provisions of 14 CFR 21.101.
Conclusion
This action affects only certain design
features on the Raytheon Model BH125
Series 400A and 600A airplanes
modified by Flight Test Associates, Inc.
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 the special
conditions for these airplanes has been
subjected to the notice and comment
procedure in several prior instances and
has been derived without substantive
change from those previously issued.
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
VerDate Aug<31>2005
16:33 Oct 03, 2005
Jkt 208002
adopting these special conditions
immediately. 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 25
Aircraft, Aviation safety, Reporting
and record keeping 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
supplemental type certification basis for
the modified Raytheon Model BH125
Series 400A and 600A airplanes,
modified by Flight Test Associates, Inc.:
1. Protection from Unwanted Effects
of High-Intensity Radiated Fields
(HIRF). Each electrical and electronic
system that performs critical functions
must be designed and installed to
ensure that the operation and
operational capability of these systems
to perform critical functions are not
adversely affected when the airplane is
exposed to high intensity radiated
fields.
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 Renton, Washington.
Kalene C. Yanamura,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 05–19859 Filed 10–3–05; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM329; Special Conditions No.
25–300–SC]
Special Conditions: Dassault-Aviation
Mystere-Falcon 50 Airplanes; HighIntensity Radiated Fields (HIRF)
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions; request
for comments.
AGENCY:
PO 00000
Frm 00006
Fmt 4700
Sfmt 4700
SUMMARY: These special conditions are
issued for Dassault-Aviation MystereFalcon 50 airplanes modified by
Premier Air Center. These modified
airplanes will have a novel or unusual
design feature when compared to the
state of technology envisioned in the
airworthiness standards for transport
category airplanes. The modification
incorporates the installation of
Universal Avionics EFI–890 Electronic
Flight Displays and Rockwell Collins
AHS–3000A Attitude Heading
Reference Systems (AHRS) that perform
critical functions. The applicable
airworthiness regulations do not contain
adequate or appropriate safety 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 that established by the
existing airworthiness standards.
DATES: The effective date of these
special conditions is September 23,
2005. Comments must be received on or
before November 3, 2005.
ADDRESSES: Comments on these special
conditions may be mailed in duplicate
to: Federal Aviation Administration,
Transport Airplane Directorate,
Attention: Rules Docket (ANM–113),
Docket No. NM329, 1601 Lind Avenue
SW., Renton, Washington 98055–4056;
or delivered in duplicate to the
Transport Airplane Directorate at the
above address. All comments must be
marked: Docket No. NM329.
FOR FURTHER INFORMATION CONTACT: Greg
Dunn, FAA, Airplane and Flight Crew
Interface Branch, ANM–111, Transport
Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington 98055–4056;
telephone (425) 227–2799; facsimile
(425) 227–1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice
and opportunity for prior public
comment is impracticable because these
procedures would significantly delay
certification of the airplane 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; however, the FAA invites
interested persons to participate in this
rulemaking by submitting written
comments, data, or views. The most
E:\FR\FM\04OCR1.SGM
04OCR1
]]>Agencies
[Federal Register Volume 70, Number 191 (Tuesday, October 4, 2005)]
[Rules and Regulations]
[Pages 57728-57730]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-19859]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM328, Special Conditions No. 25-298-SC]
Special Conditions: Raytheon Model BH125 Series 400A and 600A
Airplanes; High Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA) DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for Raytheon Model BH125
Series 400A and 600A airplanes. These airplanes will have novel and
unusual design features when compared to the state of technology
envisioned in the airworthiness standards for transport category
airplanes. The modification incorporates the installation of dual
Honeywell Model AM-250 digital altimeters. The applicable airworthiness
regulations do not contain adequate or appropriate safety 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 that provided by the existing
airworthiness standards.
DATES: The effective date of these special conditions is September 12,
2005. Comments must be received on or before November 3, 2005.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM328, 1601 Lind
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate
to the Transport Airplane Directorate at the above address. All
comments must be marked: Docket No. NM328. Comments may be inspected in
the Rules Docket weekdays, except Federal holidays, between 7:30 a.m.
and 4 p.m.
[[Page 57729]]
FOR FURTHER INFORMATION CONTACT: Mr. Greg Dunn, FAA, Airplane & Flight
Crew Interface Branch, ANM-111, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; telephone (425) 227-2799; facsimile (425) 227-
1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that notice and opportunity for prior public
comment hereon is unnecessary, as 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; however, the FAA invites interested
persons to participate in this rulemaking by submitting 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 ask that you send
us two copies of written comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning these special conditions. The docket is available for public
inspection before and after the comment closing date. If you wish to
review the docket in person, go to the address in the ADDRESSES section
of this preamble between 7:30 a.m., and 4 p.m., Monday through Friday,
except Federal holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions in light of the comments received.
If you want the FAA to acknowledge receipt of your comments on
these special conditions, include with your comments a pre-addressed,
stamped postcard on which the docket number appears. We will stamp the
date on the postcard and mail it back to you.
Background
On February 17, 2005, Flight Test Associates, Inc., of Mojave,
California, applied to the FAA, Los Angeles Aircraft Certification
Office for a supplemental type certificate (STC) to modify Raytheon
Model BH125 Series 400A and 600A airplanes. The proposed modification
incorporates the installation of dual Honeywell Model AM-250 digital
altimeters as primary instruments. The information presented is flight
critical. The altimeters installed in the airplanes have the potential
to be vulnerable to high-intensity radiated fields (HIRF) external to
the airplanes.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Flight Test Associates,
Inc., must show that the airplanes as changed, continues to meet the
applicable provisions of the regulations incorporated by reference in
Type Certificate No. A3EU, or the applicable regulations in effect on
the date of application for the change. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.''
The regulations incorporated by reference in Type Certificate No.
A3EU include Civil Aeronautics Manual 4b, as amended by Amendments 4b-1
through 4b-11.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for the modified Raytheon Model BH125
Series 400A and 600A airplanes, because of a novel or unusual design
feature, special conditions are prescribed under the provisions of
Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Raytheon Model BH125 Series 400A and 600A airplanes
must comply with the fuel vent and exhaust emission requirements of 14
CFR part 24 and the noise certification requirements of 14 CFR part 36.
Special conditions, as defined in 14 CFR 11.19, are issued in
accordance with Sec. 11.38 and become part of the type certification
basis in accordance with Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should Flight Test Associates, Inc., apply at a later
date for an STC to modify any other model included on the same type
certificate to incorporate the same novel or unusual design feature,
these special conditions would also apply to the other model under the
provisions of Sec. 21.101.
Novel or Unusual Design Features
As noted earlier, the Raytheon Model BH125 Series 400A and 600A
airplanes modified by Flight Test Associates, Inc., will incorporate
new dual primary altimeters that will perform critical functions. These
systems may be vulnerable to HIRF external to the airplane. The current
airworthiness standards of part 25 do not contain adequate or
appropriate safety standards for the protection of this equipment from
the adverse effects of HIRF. Accordingly, this system is considered to
be a novel or unusual design feature.
Discussion
There is no specific regulation that addresses protection
requirements for electrical and electronic systems from HIRF. Increased
power levels from ground-based radio transmitters and the growing use
of sensitive avionics/electronics and electrical systems to command and
control airplanes have made it necessary to provide adequate
protection.
To ensure that a level of safety is achieved equivalent to that
intended by the regulations incorporated by reference, special
conditions are needed for the Raytheon Model BH125 Series 400A and 600A
airplanes. These special conditions require that new primary altimeters
that perform critical functions be designed and installed to preclude
component damage and interruption of function due to both the direct
and indirect effects of HIRF.
High-Intensity Radiated Fields (HIRF)
With the trend toward increased power levels from ground-based
transmitters, plus the advent of space and satellite communications
coupled with electronic command and control of the airplane, the
immunity of critical digital avionics/electronics and electrical
systems to HIRF must be established.
It is not possible to precisely define the HIRF to which the
airplane will be exposed in service. There is also uncertainty
concerning the effectiveness of airframe shielding for HIRF.
Furthermore, coupling of electromagnetic energy to cockpit-installed
equipment through the cockpit window apertures is undefined. Based on
surveys and analysis of existing HIRF emitters, an adequate level of
protection exists when compliance with the HIRF protection special
condition is shown with either paragraph 1 or 2 below:
1. A minimum threat of 100 volts rms (root-mean-square) per meter
electric field strength from 10 KHz to 18 GHz.
a. The threat must be applied to the system elements and their
associated wiring harnesses without the benefit of airframe shielding.
b. Demonstration of this level of protection is established through
system tests and analysis.
2. A threat external to the airframe of the field strengths
indicated in the following table for the frequency ranges indicated.
Both peak and average field
[[Page 57730]]
strength components from the table are to be demonstrated.
------------------------------------------------------------------------
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 of the root-mean-
square (rms) over the complete modulation period.
The threat levels identified above are the result of an FAA review
of existing studies on the subject of HIRF, in light of the ongoing
work of the Electromagnetic Effects Harmonization Working Group of the
Aviation Rulemaking Advisory Committee.
Applicability
As discussed above, these special conditions are applicable to
Raytheon Model BH125 Series 400A and 600A airplanes, modified by Flight
Test Associates, Inc. Should Flight Test Associates, Inc., 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 as under the
provisions of 14 CFR 21.101.
Conclusion
This action affects only certain design features on the Raytheon
Model BH125 Series 400A and 600A airplanes modified by Flight Test
Associates, Inc. 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 the special conditions for these airplanes has
been subjected to the notice and comment procedure in several prior
instances and has been derived without substantive change from those
previously issued. 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 immediately. 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 25
Aircraft, Aviation safety, Reporting and record keeping
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 supplemental type certification basis for the modified Raytheon
Model BH125 Series 400A and 600A airplanes, modified by Flight Test
Associates, Inc.:
1. Protection from Unwanted Effects of High-Intensity Radiated
Fields (HIRF). Each electrical and electronic system that performs
critical functions must be designed and installed to ensure that the
operation and operational capability of these systems to perform
critical functions are not adversely affected when the airplane is
exposed to high intensity radiated fields.
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 Renton, Washington.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-19859 Filed 10-3-05; 8:45 am]
BILLING CODE 4910-13-P
