[Federal Register Volume 70, Number 89 (Tuesday, May 10, 2005)]
[Rules and Regulations]
[Pages 24478-24480]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-9306]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM306; Special Conditions No. 25-287-SC]


Special Conditions: Cessna Aircraft Company Model 650 Citation 
III 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 Cessna Aircraft 
Company Model 650 Citation III airplanes modified by Pro Star Aviation, 
LLC. 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 Honeywell Primus Epic Control Display 
System (CDS)/Retrofit Electronic Flight Instrument System (EFIS) 
system, and a second air data computer. 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 April 27, 
2005. Comments must be received on or before June 24, 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. NM306, 1601 Lind 
Avenue, SW., Renton, Washington, 98055-4056; or delivered in duplicate 
to the Transport Airplane Directorate at the above address. Comments 
must be marked: Docket No. NM306.

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-
1149.

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 airplanes 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 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 March 18, 2005, Pro Star Aviation, LLC, Manchester Airport, 5 
Industrial Drive, Londonderry, NH 03053, applied for a supplemental 
type certificate (STC) to modify Cessna Aircraft Company Model 650 
Citation III airplanes. These models are currently approved under Type 
Certificate No. A9NM. These Cessna airplane models are small transport 
category airplanes powered by two Garrett engines. The Cessna Model 650 
airplanes carry a total of 15 people (a pilot, co-pilot, and 13 
passengers), and have two wing tanks and a fuselage tank. The 
modification incorporates the installation of the Honeywell Primus Epic 
CDS/Retrofit EFIS system, EGPWS, and a second air data computer. The 
avionics/electronics and electrical systems installed in these 
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, Pro Star Aviation, LLC must 
show that the Cessna Aircraft Company Model 650 Citation III airplanes, 
as changed, continue to meet the applicable provisions of the 
regulations incorporated by reference in Type Certificate No. A9NM, 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

[[Page 24479]]

basis for the Cessna Model 650 airplanes include part 25 of 14 CFR 
effective February 1, 1965, as amended by amendments 25-1 through 25-
39; Sec. Sec.  25.901(c) and 25.1199 as amended by Amendments 25-1 
through 25-40; Sec. Sec.  25.1309 and 25.1351(d) as amended by 
Amendments 25-1 through 25-41; Sec. Sec.  25.177, 25.255, and 25.703 as 
amended by Amendments 25-1 through 25-42; Sec.  25.1326 as amended by 
Amendments 25-1 through 25-43; Sec.  25.1413 as amended by Amendments 
25-1 through 25-44; Sec. Sec.  25.1305 and 25.1529 as amended by 
Amendments 25-1 through 25-54. In addition, the certification basis 
includes certain special conditions, exemptions, equivalent levels of 
safety, or later amended sections of the applicable part 25 that are 
not relevant to these special conditions.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25, as amended) do not contain adequate or 
appropriate safety standards for modified Cessna Aircraft Company Model 
650 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 Cessna Model 650 airplanes 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 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 Pro Star Aviation LLC apply at a later date for 
a supplemental type certificate to modify any other model included on 
Type Certificate No. A9NM 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 Cessna Aircraft Company Model 650 airplanes 
modified by Pro Star Aviation will incorporate electrical and 
electronic systems 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 electronic and electrical 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 650 airplanes modified by 
Pro Star Aviation. 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 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 is shown with either HIRF protection 
special condition 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-8GHz..........................................      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 the 
Cessna Aircraft Company Model 650 airplanes. Should Pro Star Aviation 
LLC apply at a later date for a supplemental type certificate to modify 
any other model included on Type Certificate No. A9NM to incorporate 
the same or similar novel or unusual design feature, these special 
conditions would apply to that model as well under the provisions of 
Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
on the Cessna Model 650 airplanes modified by Pro Star Aviation LLC. 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 upon issuance. The FAA is requesting comments to allow 
interested persons to submit views that may not have been

[[Page 24480]]

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.


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 the Cessna Aircraft 
Company Model 650 Citation III airplanes modified by Pro Star Aviation 
LLC.
    1. Protection from Unwanted Effects of High-Intensity Radiated 
Fields (HIRF). Each electronic and electrical 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 April 27, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-9306 Filed 5-9-05; 8:45 am]
BILLING CODE 4910-13-P