[Federal Register Volume 68, Number 204 (Wednesday, October 22, 2003)]
[Rules and Regulations]
[Pages 60281-60283]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-26559]



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  Federal Register / Vol. 68, No. 204 / Wednesday, October 22, 2003 / 
Rules and Regulations  

[[Page 60281]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM268, Special Conditions No. 25-252-SC]


Special Conditions: Cessna Aircraft Company Cessna Model 500 
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 Cessna Aircraft 
Company Cessna Model 500 airplanes modified by Honeywell International, 
Inc. These modified 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 RVSM 
(reduced vertical separation minimum)-capable AM-250 electronic 
barometric 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 October 14, 
2003. Comments must be received on or before November 21, 2003.

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. NM268, 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. NM268.

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: The FAA has determined that notice and 
opportunity for prior public comment are 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 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 were 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 based on the comments we receive.
    If you want the FAA to acknowledge receipt of your comments on this 
proposal, 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 12, 2003, Honeywell International, Inc., 23500 W. 105th 
St., Olathe, KS 66061, applied for a supplemental type certificate 
(STC) to modify Cessna (Citation) Model 500 airplanes. This model is 
currently approved under Type Certificate No. A22CE. The Cessna Model 
500 airplanes are executive type transports that have two aft mounted 
turbine engines, a minimum passenger load of 9 passengers, and a 
maximum operating speed of 260 to 287 knots, depending on altitude. The 
modification, under one supplemental type certificate (STC) project, 
incorporates the installation of dual Honeywell RVSM-capable AM-250 
electronic barometric altimeters.
    The dual Honeywell AM-250 barometric altimeters provide the 
aircraft baro-corrected altitude information, also corrected for static 
source error (SSE), which enables the aircraft to be capable of RVSM 
operations. The dual AM-250 barometric altimeters replace the existing 
pilot and copilot pneumatic altimeters. Since the AM-250 altimeters use 
electronics to transmit altimeter data to the pilots, as well as to 
other equipment, they may be susceptible to electrical and magnetic 
interference caused by high-intensity radiated fields (HIRF). This 
disruption of signals could result in misleading altimeter information 
to the pilots or loss of altimeter information.

Type of Certification Basis

    Under the provisions of 14 CFR 21.101, Honeywell International, 
Inc. must show that the Cessna Model 500 airplanes, as changed, 
continue to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate No. 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 ``the original type 
certification basis.'' The certification basis for the modified Cessna 
Model 500 airplanes includes Part 25 of the Federal Aviation 
Regulations effective February 1, 1965, as amended by Amendments 25-1 
through 25-17. Other applicable amendments, Federal aviation 
regulations, and special conditions are

[[Page 60282]]

also noted in Type Certificate Data Sheet (TCDS) A22CE.
    If the Administrator finds that the applicable airworthiness 
regulations (that is, 14 CFR part 25, as amended) do not contain 
adequate or appropriate safety standards for the Cessna Model 500 
airplanes because of novel or unusual design features, special 
conditions are prescribed under the provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Cessna Model 500 airplanes must comply with the fuel 
vent and exhaust emission requirement of 14 CFR part 34 and the noise 
certification requirement of 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 issues. Should Honeywell International, Inc. apply at a later 
date for a supplemental type certificate to modify any other model 
already included on the same type certificate to incorporate the same 
novel or unusual design features, these special conditions would also 
apply to the other model under the provisions of 14 CFR 21.101.

Novel or Unusual Design Features

    The Cessna Model 500 airplanes will incorporate, under one 
supplemental type certificate (STC) project, the installation of dual 
Honeywell AM-250 barometric altimeters. Because these altimeters use 
electronics to a far greater extent than the original pneumatic or 
servo altimeters, they may be more susceptible to electrical and 
magnetic interference caused by high-intensity radiated fields (HIRF) 
external to the airplane. 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, these instruments are 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 Cessna Model 500 airplanes modified to 
include the new altimeters. These special conditions will require that 
the new Honeywell AM-250 barometric altimeters, which 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 in accordance 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 table below for the frequency ranges indicated. Both 
peak and average field strength components from the table below 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 
Cessna Model 500 airplanes modified by Honeywell International, Inc. to 
include dual Honeywell AM-250 barometric altimeters. should Honeywell 
International, Inc. apply at a later date for a supplemental type 
certificate to modify any other model already included on Type 
Certificate A22CE to incorporate; the same novel or unusual design 
features, these special conditions would apply to that model as well 
under the provisions of 14 CFR 21.101.

Conclusion

    This action affects only certain design features on Cessna Model 
500 airplanes modified by Honeywell International, 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 this airplane has been 
subjected to 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.


[[Page 60283]]



0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
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 Cessna model 500 
airplanes modified by Honeywell International, 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, on October 14, 2003.
Neil D. Schalekamp,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service, ANM-100.
[FR Doc. 03-26559 Filed 10-21-03; 8:45 am]
BILLING CODE 4910-13-M