[Federal Register Volume 64, Number 169 (Wednesday, September 1, 1999)]
[Rules and Regulations]
[Pages 47649-47651]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22751]
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Rules and Regulations
Federal Register
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Federal Register / Vol. 64, No. 169 / Wednesday, September 1, 1999 /
Rules and Regulations
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-163; Special Conditions No. 25-147-SC]
Special Conditions: Rockwell Collins; Boeing Model 737-300/-400/-
500 Series Airplanes; High-Intensity Radiated Fields (HIRF)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for Boeing Model 737-300/-
400/-500 series airplanes modified by Rockwell Collins. These modified
airplanes will have a novel or unusual design feature associated with
the Rockwell Collins Multi-Mode Receiver (MMR) System. The applicable
airworthiness regulations do not contain adequate or appropriate safety
standards for this design feature. These special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to that established by the
existing airworthiness standards.
DATES: The effective date of these special conditions is August 23,
1999. Comments must be received on or before October 1, 1999.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attention: Rules Docket (ANM-114), Docket No. NM-163, 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. NM-163. Comments may be
inspected in the Rules Docket weekdays, except Federal holidays,
between 7:30 a.m. and 4:00 p.m.
FOR FURTHER INFORMATION CONTACT: Mark Quam, FAA, Standardization
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone
(425) 227-2145; facsimile (425) 227-1149.
SUPPLEMENTARY INFORMATION:
FAA's Determination as to Need for Public Process
The FAA has determined that notice and opportunity for prior public
comment hereon are impracticable because those procedures would
significantly delay issuance of the approval design and, thus, the
delivery of the affected aircraft. (The aircraft are scheduled for
delivery in mid-September 1999.)
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. Thus, the FAA has previously provided
the public with a number of opportunities to comment on proposed
special conditions that are substantively identical to those at issue;
and the FAA is reasonably assured that all interested members of the
public have had an opportunity to comment and that their comments have
been fully considered. The FAA, therefore, finds that good cause exists
for making these special conditions effective upon issuance.
Comments Invited
Although this action is in the form of final special conditions
and, for the reasons stated above, is not preceded by notice and an
opportunity for public comment, comments are invited on this rule.
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 NM-163.'' The postcard will be date stamped and
returned to the commenter.
Background
On October 15, 1998, Rockwell Collins, Business and Regional
Systems, 400 Collins Road NE., Cedar Rapids, Iowa 52498, made
application to the FAA for a Supplemental Type Certificate (STC) for
the Boeing Model 737-300/-400/-500 series airplanes. These airplanes
are low-wing, pressurized transport category airplanes with twin, wing-
mounted, jet engines. They are capable of seating between 110 and 147
passengers, depending upon the model and configuration. The proposed
configuration of these modified airplanes will incorporate a Multi-Mode
Receiver (MMR) system manufactured by Rockwell Collins. The affected
aircraft are scheduled for delivery to the first customers in mid-
September 1999.
The Rockwell Collins MMR is a single integrated unit that enables
approaches using instrument landing systems, microwave landing systems,
and global navigation satellite system functions. These functions can
be susceptible to disruption of both command and response signals as a
result of electrical and magnetic interference caused by high-intensity
radiated fields (HIRF) external to the airplane. This disruption of
signals could result in loss of critical flight displays and
annunciations, or could present misleading information to the pilot.
Type Certification Basis
Under the provisions of 14 CFR 21.101 (``Designation of applicable
regulations''), Rockwell Collins must show that the Boeing Model 737-
300/-400/-500 series airplanes, as modified to include the MMR
installation, continue to meet the applicable provisions of the
regulations incorporated by reference in Type Certificate No. A16WE or
the applicable regulations in effect on the date of
[[Page 47650]]
application for the change. The regulations incorporated by reference
in the type certificate are commonly referred to as the ``original type
certification basis.'' The specific regulations included in the
certification basis for the Boeing Model 737-300/-400/-500 series
airplanes include 14 CFR part 25, as amended by amendment 25-1 through
25-3, 25-7, 25-8, and 25-15.
Purpose of Special Conditions
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Boeing Model 737-300/-400/-500
series airplanes because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16 (``Special
conditions'').
In addition to the applicable airworthiness regulations and special
conditions, the Boeing Model 737-300/-400/-500 must comply with the
part 25 fuel vent and exhaust emission requirements of 14 CFR part 34,
and the part 25 noise certification requirements of 14 CFR part 36.
Special conditions, as appropriate, are issued in accordance with
Sec. 11.49, as required by Secs. 11.28 and 11.29, and become part of
the airplane's 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 Rockwell Collins apply at a later date for a
supplemental type certificate 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(a)(1).
Novel or Unusual Design Features
The modified Boeing Model 737-300/-400/-500 series airplanes will
incorporate the Rockwell Collins MMR system, which performs critical
functions. The MMR system contains electronic equipment for which the
current airworthiness standards (14 CFR part 25) do not contain
adequate or appropriate safety standards that address protecting 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 requirements for
protection of electrical and electronic systems from HIRF. Increased
power levels from ground-based radio transmitters and the growing use
of sensitive electrical and electronic systems to command and control
airplanes have made it necessary to provide adequate protection.
To ensure that a level of safety is achieved that is equivalent to
that intended by the regulations incorporated by reference, special
conditions are needed for the Boeing Model 737-300/-400/-500 airplanes
modified to include the Rockwell Collins MMR system. These special
conditions will require that this system, which performs critical
functions, must 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 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 per meter peak 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 following field
strengths for the frequency ranges indicated.
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Field Strength (volts
per meter)
Frequency -------------------------
Peak Average
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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
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The field strengths are expressed in terms of peak root-mean-square
(rms) values.
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
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Rulemaking Advisory Committee. In general, these standards are less
critical than the threat level that was previously used as the basis
for some earlier special conditions.
Applicability
As discussed above, these special conditions are applicable to the
Boeing Model 737-300/-400/-500 series airplanes modified by Rockwell
Collins to include the MMR system. Should Rockwell Collins apply at a
later date for a design change approval to modify any other model that
may be included on Type Certificate A16WE and incorporating the same
novel or unusual design feature, these special conditions would apply
to that model as well under the provisions of Sec. 21.101(a)(1).
Conclusion
This action affects only certain design features on the Boeing 737-
300/-400/-500 airplanes as modified to include the Rockwell Collins MMR
system installation. 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 airplanes.
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. 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 immediately. Therefore, these special conditions are being
made effective 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 Boeing Model 737-300/
-400/-500 series airplanes as modified by Rockwell Collins to include
the Rockwell Collins Multi-Mode Receiver.
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
operations 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 August 23, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-22751 Filed 8-31-99; 8:45 am]
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