Special Conditions: Raytheon Aircraft Company Model HS.125 Airplanes; High-Intensity Radiated Fields (HIRF), 75002-75004 [05-24158]
Download as PDF
<![CDATA[
75002
Federal Register / Vol. 70, No. 242 / Monday, December 19, 2005 / Rules and Regulations
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
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
VerDate Aug<31>2005
17:05 Dec 16, 2005
Jkt 208001
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
Raytheon Model B200, B200C, 300,
B300, and B300C. Should Envoy
Aerospace 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
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 the Raytheon
Model B200, B200C, 300, B300, and
B300C airplanes modified by Envoy
PO 00000
Frm 00008
Fmt 4700
Sfmt 4700
Aerospace to add the Universal
Avionics EFI–890R system.
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
December 5, 2005.
James E. Jackson,
Acting Manager, Small Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 05–24159 Filed 12–16–05; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM337; Special Conditions No.
25–310–SC]
Special Conditions: Raytheon Aircraft
Company Model HS.125 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 a Raytheon Aircraft Company
Model HS.125 airplane modified by
AeroMech Incorporated. This modified
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. The modification
incorporates the installation of
Innovative Solutions and Support air
data display units (ADDU). These
systems 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 highintensity radiated fields (HIRF). These
special conditions contain the
additional safety standards that the
Administrator considers necessary to
establish a level of safety equivalent to
E:\FR\FM\19DER1.SGM
19DER1
Federal Register / Vol. 70, No. 242 / Monday, December 19, 2005 / Rules and Regulations
that established by the existing
airworthiness standards.
DATES: The effective date of these
special conditions is December 9, 2005.
Comments must be received on or
before January 18, 2006.
ADDRESSES: You must mail two copies
of your comments to: Federal Aviation
Administration, Transport Airplane
Directorate, Attention: Rules Docket
(ANM–113), Docket No. NM337, 1601
Lind Avenue, SW., Renton, Washington
98055–4056. You may deliver two
copies to the Transport Airplane
Directorate at the above address. You
must mark your comments: Docket No.
NM337. You can inspect comments in
the Rules Docket weekdays, except
Federal holidays, between 7:30 a.m. and
4 p.m.
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, 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 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.
You may inspect the docket 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
VerDate Aug<31>2005
17:05 Dec 16, 2005
Jkt 208001
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
based on the comments we receive.
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 June 6, 2005, AeroMech
Incorporated, 1616 Hewitt Avenue,
Suite 312, Everett, Washington 98201,
applied for a supplemental type
certificate (STC) to modify a Raytheon
Aircraft Company Model HS.125 Series
400A airplane. This model is currently
approved under Type Certificate No.
A3EU. The Raytheon Model HS.125
airplane is a small transport category
airplane powered by two turbine
engines. It operates with a 2-pilot crew
and can seat up to 15 passengers. The
modification incorporates the
installation of Innovative Solutions and
Support air data display units. The
avionics/electronics and electrical
systems installed in this airplane have
the potential to be vulnerable to highintensity radiated fields (HIRF) external
to the airplane.
Type Certification Basis
Under the provisions of 14 CFR
21.101, AeroMech Incorporated must
show that Raytheon Aircraft Company
Model HS.125 Series 400A airplane, 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 certification
basis for the Raytheon Aircraft Company
Model HS.125 Series 400A airplane
includes Civil Air Regulations (CAR) 10,
British Civil Airworthiness
Requirements, and Special Conditions.
This certification is equivalent to CAR
4b dated December 1953, Amendment
4b–1 through Amendment 4b–11,
exclusive of CAR 4b.350(e), and
includes Special Regulations SR.422B.
Type Certificate No. A3EU was
amended to include HS.125 Series 400A
on November 15, 1968. Compliance over
and above certification basis
requirements has been met with CAR
Amendment 4B–12 and Amendment
4B–14. Compliance has been established
with the special retroactive
PO 00000
Frm 00009
Fmt 4700
Sfmt 4700
75003
requirements of 14 CFR 25.2 as
amended by Amendment 25–1 through
Amendment 25–20, 14 CFR 21 at
Amendment 21–27, and 14 CFR
36(1)(c)(2).
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 Raytheon Model
HS.125 Series 400A airplane because of
a novel or unusual design feature,
special conditions are prescribed under
§ 21.16.
In addition to the applicable
airworthiness regulations and special
conditions, Raytheon Aircraft Company
Model HS.125 Series 400A 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.
Special conditions, as defined in 14
CFR 11.19, are issued under § 11.38 and
become part of the type certification
basis under § 21.101.
Special conditions are initially
applicable to the model for which they
are issued. Should AeroMech
Incorporated apply at a later date for a
supplemental type certificate to modify
any other model included on Type
Certificate No. A3EU to incorporate the
same or similar novel or unusual design
feature, these special conditions would
also apply to the other model under
§ 21.101.
Novel or Unusual Design Features
As noted earlier, Raytheon Model
HS.125 airplane modified by AeroMech
Incorporated will incorporate
Innovative Solutions and Support air
data display units that will perform
critical functions. These systems may be
vulnerable to high-intensity radiated
fields 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
E:\FR\FM\19DER1.SGM
19DER1
75004
Federal Register / Vol. 70, No. 242 / Monday, December 19, 2005 / Rules and Regulations
reference, special conditions are needed
for Raytheon Aircraft Company Model
HS.125 Series 400A airplane modified
by AeroMech Incorporated. These
special conditions require that new
avionics/electronics and electrical
systems 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, and the advent of space
and satellite communications coupled
with electronic command and control of
the airplane, the immunity of critical
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 identified in the table
below for the frequency ranges
indicated. Both peak and average field
strength components from the table are
to be demonstrated.
Frequency
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 ...............
VerDate Aug<31>2005
Frequency
Field strength
(volts per meter)
The Special Conditions
Accordingly, pursuant to the
8 GHz–12 GHz .............
3000
300 authority delegated to me by the
12 GHz–18 GHz ...........
2000
200 Administrator, the following special
18 GHz–40 GHz ...........
600
200
conditions are issued as part of the
The field strengths are expressed in terms supplemental type certification basis for
of peak root-mean-square (rms) over the com- the Raytheon Aircraft Company Model
plete modulation period.
HS.125 Series 400A airplane modified
by AeroMech Incorporated.
The threat levels identified above are
1. Protection from Unwanted Effects
the result of an FAA review of existing
of HIRF. Each electrical and electronic
studies on the subject of HIRF, in light
system that performs critical functions
of the ongoing work of the
must be designed and installed to
Electromagnetic Effects Harmonization
ensure that the operation and
Working Group of the Aviation
operational capability of these systems
Rulemaking Advisory Committee.
to perform critical functions are not
Applicability
adversely affected when the airplane is
exposed to high-intensity radiated
As discussed above, these special
fields.
conditions are applicable to a Raytheon
2. For the purpose of these special
Aircraft Company Model HS.125 Series
conditions, the following definition
400A airplane modified by AeroMech
applies: Critical Functions: Functions
Incorporated. Should AeroMech
whose failure would contribute to or
Incorporated apply at a later date for a
cause a failure condition that would
supplemental type certificate to modify
prevent the continued safe flight and
any other model included on Type
landing of the airplane.
Certificate No. A3EU to incorporate the
Issued in Renton, Washington, on
same or similar novel or unusual design
December 9, 2005.
feature, these special conditions would
Ali Bahrami,
apply to that model as well under
§ 21.101.
Manager, Transport Airplane Directorate,
Peak
Average
Aircraft Certification Service.
[FR Doc. 05–24158 Filed 12–16–05; 8:45 am]
Conclusion
This action affects only certain novel
or unusual design features on a
Raytheon Aircraft Company Model
HS.125 Series 400A airplane modified
by AeroMech Incorporated. 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 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
Field strength
imminent, the FAA has determined that
(volts per meter)
prior public notice and comment are
Peak
Average unnecessary and impracticable, and
good cause exists for adopting these
50
50 special conditions upon issuance. The
50
50
FAA is requesting comments to allow
50
50
100
100 interested persons to submit views that
50
50 may not have been submitted in
50
50 response to the prior opportunities for
100
100 comment described above.
100
700
700
2000
3000
3000
1000
17:05 Dec 16, 2005
Jkt 208001
100
50
100
200
200
200
200
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
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:
PO 00000
Frm 00010
Fmt 4700
Sfmt 4700
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2005–20848; Directorate
Identifier 2005–NE–02–AD; Amendment 39–
14323; AD 2005–20–26]
RIN 2120–AA64
Airworthiness Directives; Aviointeriors
S.p.A. (formerly ALVEN), Series 312
Box Mounted Seats; Correction
Federal Aviation
Administration, DOT.
ACTION: Final rule; correction.
AGENCY:
SUMMARY: This document makes a
correction to Airworthiness Directive
(AD) 2005–20–26. That AD applies to
Aviointeriors S.p.A. (formerly ALVEN),
series 312 box mounted seats. That AD
published in the Federal Register on
October 12, 2005 (70 FR 59243). This
document corrects the AD number in
the Amendatory section. In all other
respects, the original document remains
the same.
EFFECTIVE DATE: Effective December 19,
2005.
E:\FR\FM\19DER1.SGM
19DER1
]]>Agencies
[Federal Register Volume 70, Number 242 (Monday, December 19, 2005)]
[Rules and Regulations]
[Pages 75002-75004]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-24158]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM337; Special Conditions No. 25-310-SC]
Special Conditions: Raytheon Aircraft Company Model HS.125
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 a Raytheon Aircraft
Company Model HS.125 airplane modified by AeroMech Incorporated. This
modified 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. The modification
incorporates the installation of Innovative Solutions and Support air
data display units (ADDU). These systems 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
[[Page 75003]]
that established by the existing airworthiness standards.
DATES: The effective date of these special conditions is December 9,
2005. Comments must be received on or before January 18, 2006.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attention:
Rules Docket (ANM-113), Docket No. NM337, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. You may deliver two copies to the
Transport Airplane Directorate at the above address. You must mark your
comments: Docket No. NM337. You can inspect comments in the Rules
Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.
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, 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 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. You may inspect the docket 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 based on the comments we receive.
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 June 6, 2005, AeroMech Incorporated, 1616 Hewitt Avenue, Suite
312, Everett, Washington 98201, applied for a supplemental type
certificate (STC) to modify a Raytheon Aircraft Company Model HS.125
Series 400A airplane. This model is currently approved under Type
Certificate No. A3EU. The Raytheon Model HS.125 airplane is a small
transport category airplane powered by two turbine engines. It operates
with a 2-pilot crew and can seat up to 15 passengers. The modification
incorporates the installation of Innovative Solutions and Support air
data display units. The avionics/electronics and electrical systems
installed in this airplane have the potential to be vulnerable to high-
intensity radiated fields (HIRF) external to the airplane.
Type Certification Basis
Under the provisions of 14 CFR 21.101, AeroMech Incorporated must
show that Raytheon Aircraft Company Model HS.125 Series 400A airplane,
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 certification basis for the Raytheon
Aircraft Company Model HS.125 Series 400A airplane includes Civil Air
Regulations (CAR) 10, British Civil Airworthiness Requirements, and
Special Conditions. This certification is equivalent to CAR 4b dated
December 1953, Amendment 4b-1 through Amendment 4b-11, exclusive of CAR
4b.350(e), and includes Special Regulations SR.422B. Type Certificate
No. A3EU was amended to include HS.125 Series 400A on November 15,
1968. Compliance over and above certification basis requirements has
been met with CAR Amendment 4B-12 and Amendment 4B-14. Compliance has
been established with the special retroactive requirements of 14 CFR
25.2 as amended by Amendment 25-1 through Amendment 25-20, 14 CFR 21 at
Amendment 21-27, and 14 CFR 36(1)(c)(2).
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 Raytheon Model HS.125 Series 400A
airplane because of a novel or unusual design feature, special
conditions are prescribed under Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, Raytheon Aircraft Company Model HS.125 Series 400A 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.
Special conditions, as defined in 14 CFR 11.19, are issued under
Sec. 11.38 and become part of the type certification basis under Sec.
21.101.
Special conditions are initially applicable to the model for which
they are issued. Should AeroMech Incorporated apply at a later date for
a supplemental type certificate to modify any other model included on
Type Certificate No. A3EU to incorporate the same or similar novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
Novel or Unusual Design Features
As noted earlier, Raytheon Model HS.125 airplane modified by
AeroMech Incorporated will incorporate Innovative Solutions and Support
air data display units that will perform critical functions. These
systems may be vulnerable to high-intensity radiated fields 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
[[Page 75004]]
reference, special conditions are needed for Raytheon Aircraft Company
Model HS.125 Series 400A airplane modified by AeroMech Incorporated.
These special conditions require that new avionics/electronics and
electrical systems 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, and the advent of space and satellite communications
coupled with electronic command and control of the airplane, the
immunity of critical 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
identified in the table below for the frequency ranges indicated. Both
peak and average field 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 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 a
Raytheon Aircraft Company Model HS.125 Series 400A airplane modified by
AeroMech Incorporated. Should AeroMech Incorporated apply at a later
date for a supplemental type certificate to modify any other model
included on Type Certificate No. A3EU to incorporate the same or
similar novel or unusual design feature, these special conditions would
apply to that model as well under Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on a Raytheon Aircraft Company Model HS.125 Series 400A airplane
modified by AeroMech Incorporated. 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 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 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 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 supplemental type certification basis for the Raytheon Aircraft
Company Model HS.125 Series 400A airplane modified by AeroMech
Incorporated.
1. Protection from Unwanted Effects of 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, on December 9, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-24158 Filed 12-16-05; 8:45 am]
BILLING CODE 4910-13-P
