[Federal Register Volume 61, Number 158 (Wednesday, August 14, 1996)]
[Rules and Regulations]
[Pages 42144-42146]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20756]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-130; Special Conditions No. 25-ANM-120]
Special Conditions: Cessna Model 550 (Serial Number 550-0801 and
on); High-Intensity Radiated Fields
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Cessna Model 550
airplane, serial number 550-0801 and on. These airplanes utilize new
avionics/electronic systems, such as an Electronic Flight Instrument
Systems (EFIS), which perform critical functions. The applicable
regulations do not contain adequate or appropriate safety standards for
the protection of this system 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 August 6,
1996. Comments must be received on or before September 13, 1996.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Office of the Assistant
Chief Counsel, Attn: Rules Docket (ANM-7), Docket No. NM-130, 1601 Lind
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate
to the Office of the Assistant Chief Counsel at the above address.
Comments must be marked: Docket No. NM-130. 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 (206) 227-2145; facsimile
(206) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA has determined that good cause exists for making these
special conditions effective upon issuance; however, interested persons
are invited to submit such written data, views, or arguments as they
may desire. Communications should identify the regulatory docket and
special condition 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. These
special conditions may be changed in light of the comments received.
All comments submitted 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. Persons wishing the FAA to acknowledge receipt of their
comments submitted in response to this request must submit with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. NM-130.'' The postcard will
be date stamped and returned to the commenter.
Background
On June 30, 1994, Cessna Aircraft Company, One Cessna Boulevard,
Wichita, Kansas, applied for a type design change to the Model 550. The
Model 550 airplanes are pressurized, executive transport type
airplanes, powered by two fuselage-mounted turbofan engines and
approved under Type Certificate No A22CE. As changed, these airplanes
will differ from previously approved Model 550 airplanes, in part, by
the installation of Pratt & Whitney Canada PW530A engines with thrust
reversers; trailing link landing gear; an Electronic Flight Instrument
System (EFIS); digital anti-skid system; structural, electrical, and
hydraulic modifications to support the engine and landing gear change;
and a weight increase. The applicant intends to introduce the changes
in production beginning with serial number 550-0801.
Amended Type Certification Basis
Under the provisions of Sec. 21.101 of 14 CFR part 21, Cessna
Aircraft Company must show that the Model 550, as changed, continues to
meet the applicable provisions of the regulations incorporated by
reference in Type Certificate A22CE, 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,
including those referenced in A22CE, that apply to the Model 550,
serial number 550-0801 and on, are as follows:
(1) Part 25 of the Federal Aviation Regulations effective February
1, 1965, as amended by Amendments 25-1 through 25-17; with the
following exceptions: Section 25.305, as amended by Amendments 25-1
through 25-54. Section 25.1401, as amended by Amendments 25-1 through
25-27. Section 25.1387, as amended by Amendments 25-1 through 25-30.
Sections 25.1303(a)(2) and 25.1385(c), as amended by Amendments 25-1
through 25-38.
Sections 25.125, 25.251, 25.337, 25.493, 25.731, 25.733, 25.735,
25.867, 25.869, 25.901, 25.903, 25.933, 25.934, 25.939, 25.943, 25.951,
25.952, 25.1001, 25.1041, 25.1043, 25.1045, 25.1091, 25.1093, 25.1103,
25.1121, 25.1123, 25.1143, 25.1163, 25.1165, 25.1181, 25.1183, 25.1185,
25.1189, 25.1195, 25.1197, 25.1203, 25.1205 (revoked), 25.1207,
25.1305, 25.1316, 25.1322, 25.1326, 25.1337, 25.1351, 25.1438, 25.1521,
25.1549, and 25.1551, as amended by Amendments 25-1 through 25-82.
(2) Part 36 of the Federal Aviation Regulations effective December
1, 1969, plus any amendments in effect at the time of certification.
[[Page 42145]]
(3) Part 34 of the Federal Aviation Regulations effective September
10, 1990, plus any amendments in effect at the time of engine
manufacture.
(4) For Electronic Flight Instrument Systems only, compliance must
be demonstrated for the additional regulations: Sections 25.1301, and
25.1303(b), as amended by Amendments 25-1 through 25-38; 25.1309,
25.132 (a), (b), (d) and (e), 25.1331, 25.1333, and 25.1335, as amended
by Amendments 25-1 through 25-41.
These special conditions form an additional part of the type
certification basis.
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 Cessna Model 550, serial number
550-0801 and on, because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16 to
establish a level of safety equivalent to that established in the
regulations.
Special conditions, as appropriate, are issued in accordance with
14 CFR 11.49 after public notice, as required by Secs. 11.28 and
11.29(b), 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 an amended type
certificate to include a new model or 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). Similarly,
these special conditions would also apply to Model 550 airplanes with
serial numbers earlier than 550-0801, if those airplanes are modified
to incorporate the same novel or unusual design feature.
Novel or Unusual Design Features
The Cessna Model 550, serial number 550-0801 and on, incorporates
new avionics/electronic systems, such as an electronic flight
instrument system (EFIS), that perform critical functions. These
systems may be vulnerable to high-intensity radiated fields (HIRF)
external to the airplane.
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 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 equivalent to that
intended by the regulations incorporated by reference, a special
condition is needed for the Cessna Model 550, serial number 550-0801
and on, as modified by Cessna Aircraft Company, which requires that new
electrical and electronic systems, such as the EFIS, 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 systems, such as the EFIS, 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 paragraphs 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.
------------------------------------------------------------------------
Peak (V/ (Average
Frequency M) (V/M)
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10 KHz-100 KHz...................................... 50 50
100 KHz-500 KHz..................................... 60 60
500 KHz-2 MHz....................................... 70 70
2 MHz-30 MHz........................................ 200 200
30 MHz-100 MHz...................................... 30 30
100 MHz-200 MHz..................................... 150 33
200 MHz-400 MHz..................................... 70 70
400 MHz-700 MHz..................................... 4,020 935
700 MHz-1 GHz....................................... 1,700 170
1 GHz-2GHz.......................................... 5,000 990
2 GHz-4 GHz......................................... 6,680 840
4 GHz-6 GHz......................................... 6,850 310
6 GHz-8 GHz......................................... 3,600 670
8 GHz-12 GHz........................................ 3,500 1,270
12 GHz-18 GHz....................................... 3,500 360
18 GHz-40 GHz....................................... 2,100 750
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As discussed above, these special conditions are applicable to
those Cessna Model 550 airplanes that utilize avionics/electronics
systems which perform critical functions. Should Cessna apply at a
later date for an amended type certificate to include a new model or to
modify any other model included on type Certificate No. A22CE to
incorporate 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). Although the manufacturer intends to introduce these
changes in production beginning with serial number 550-0801, the
special conditions would be equally applicable to earlier airplanes if
those airplanes are modified to incorporate the same novel or unusual
design features.
Conclusion
This action affects only certain design features on Cessna Model
550 airplanes, serial number 550-0801 and on. 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 this airplane has been
subject 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 this special condition is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
[[Page 42146]]
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 Cessna Model 550, when equipped
with avionics/electronics systems which perform critical functions.
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 this special condition, 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 6, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service, ANM-100.
[FR Doc. 96-20756 Filed 8-13-96; 8:45 am]
BILLING CODE 4910-13-M
