[Federal Register Volume 66, Number 240 (Thursday, December 13, 2001)]
[Rules and Regulations]
[Pages 64349-64351]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-30638]



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  Federal Register / Vol. 66, No. 240 / Thursday, December 13, 2001 / 
Rules and Regulations  

[[Page 64349]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM203; Special Conditions No. 25-193-SC]


Special Conditions: Canadair Model CL-600-2A12, 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 Canadair Model CL-600-
2A12 airplanes modified by Gulfstream Aerospace. These modified 
airplanes 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 an electronic flight instrument system that performs 
critical functions. The applicable airworthiness 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 November 30, 
2001. Comments must be received on or before January 14, 2002.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM203, 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. NM203. Comments may be 
inspected in the Rules Docket weekdays, except Federal holidays, 
between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Meghan Gordon, FAA, Standardization 
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone 
(425) 227-2138; facsimile (425) 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 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 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 these special conditions must include a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. NM203.'' The postcard will be date stamped and returned 
to the commenter.

Background

    On July 27, 2001, Gulfstream Aerospace, W 6365 Discovery Drive, 
Appleton, WI, 54914, applied for a Supplemental Type Certificate (STC) 
to modify Canadair Model CL-600-2A12 airplanes. The Model CL-600-2A12 
is a small transport category airplane, powered by two General Electric 
CF-34-1A engines, with a maximum takeoff weight of 42,100 pounds. This 
airplane operates with a 2-pilot crew and can hold up to 20 passengers. 
The modification incorporates the installation of a Collins Electronic 
Flight Instrument System. 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, Gulfstream Aerospace must 
show that the Model CL-600-2A12, as changed, continues to meet the 
applicable provisions of the regulations incorporated by reference in 
Type Certificate No. A21EA, 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 included in the 
certification basis for the Model CL-600-2A12 include 14 CFR part 25, 
dated February 1, 1965, including amendments 25-1 through 25-37, plus 
Secs. 25.675(a), 25.685(a), 25.733(c), 25.775(e), 25.787(c), 25.815, 
25.841(b), 25.951(a), 25.979(d) and (e), 25.1041, 25.1143(e), 
25.1303(a), 25.1322, 25.1385(c), 25.1557(b), 25.1583(a), as amended by 
25-38; Secs. 25.901(b) and (c), 25.903(c) and (e), 25.933(a), 25.943, 
25.959, 25.1091(a) and (d), 25.1145(c), 25.1199(b) and (c), 25.1207, 
25.1549, 25.1585(a)(9), as amended by 25-40; Sec. 25.1309, as amended 
by 25-41; Sec. 25.1353(c), as amended by 25-42; Secs. 25.571 and 
25.629(d)(4) (v), as amended by 25-45; Secs. 25.351 and 25.603, as 
amended by 25-46; and Special Condition 25-ANM-01, dated March 8, 1983.
    If the Administrator finds that the applicable airworthiness 
regulations (that is, part 25, as amended) do not contain adequate or 
appropriate safety standards for the Model CL-600-2A12 airplanes 
modified by Gulfstream Aerospace 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 Model CL-600-2A12 must comply with the fuel vent and 
exhaust emission requirements of part 34 and the noise certification 
requirements of part 36.

[[Page 64350]]

    Special conditions, as defined in Sec. 11.19, are issued in 
accordance with Sec. 11.38, 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 Gulfstream Aerospace 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

    As noted earlier, the Model CL-600-2A12 airplanes modified by 
Gulfstream Aerospace will incorporate a Collins Electronic Flight 
Instrument System that will perform critical functions. This system may 
be vulnerable to high-intensity radiated fields (HIRF) 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 that is equivalent to 
that intended by the regulations incorporated by reference, special 
conditions are needed for the Model CL-600-2A12 airplanes modified by 
Gulfstream Aerospace. 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, plus 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 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 following field 
strengths 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
12GHz-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 
Canadair Model CL-600-2A12 airplanes modified by Gulfstream Aerospace. 
Should Gulfstream Aerospace 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 apply to that model as well under the 
provisions of Sec. 21.101(a)(1).

Conclusion

    This action affects only certain novel or unusual design features 
on Canadair Model CL-600-2A12 airplanes modified by Gulfstream 
Aerospace. 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 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 Canadair Model CL-600-
2A12 airplanes modified by Gulfstream Aerospace.
    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

[[Page 64351]]

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 November 30, 2001.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-30638 Filed 12-12-01; 8:45 am]
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