[Federal Register Volume 71, Number 180 (Monday, September 18, 2006)]
[Rules and Regulations]
[Pages 54576-54578]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-15401]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM351; Special Conditions No. 25-325-SC]


Special Conditions: Gulfstream Aerospace Corporation Model G150 
Airplanes; High-Intensity Radiated Fields (HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

-----------------------------------------------------------------------

SUMMARY: The FAA issues these special conditions for Gulfstream 
Aerospace Corporation Model G150 airplanes modified by Gulfstream 
Aerospace Corporation, Dallas, Texas. These modified airplanes will 
have novel or unusual design features when compared with the state of 
technology envisioned in the airworthiness standards for transport 
category airplanes. The modification consists of installing an 
electronic laser inertial reference system. The applicable 
airworthiness regulations do not contain adequate or

[[Page 54577]]

appropriate safety standards for protecting these systems from 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 September 8, 
2006.
We must receive your comments on or before October 18, 2006.

ADDRESSES: You may mail or deliver comments on these special conditions 
in duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attention: Rules Docket (ANM-113), Docket No. NM351, 1601 
Lind Avenue SW., Renton, Washington 98057-3356. You must mark your 
comments Docket No. NM351.

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 98057-3356; telephone (425) 227-2799; facsimile (425) 227-
1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA has determined that notice and opportunity for prior public 
comment for these special conditions is impracticable because these 
procedures would significantly delay certification and 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. We therefore 
find that good cause exists for making these special conditions 
effective upon issuance. However, we invite interested persons to take 
part in this rulemaking by submitting written comments. 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 
about these special conditions. You may inspect the docket 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 
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 June 9, 2006, Gulfstream Aerospace Corporation, Dallas, Texas, 
applied for a supplemental type certificate (STC) to modify Gulfstream 
G150 airplanes. The Gulfstream G150 is a low-wing, pressurized, 
transport category airplane with two fuselage-mounted jet engines. It 
can seat up to 19 passengers, with a crew of two pilots. The 
modification consists of installing an electronic laser inertial 
reference system. These systems have a potential to be vulnerable to 
high-intensity radiated fields (HIRF) external to the airplane.

Type Certification Basis

    Under provisions of 14 CFR 21.101, Gulfstream Aerospace Corporation 
must show that the Gulfstream G150 airplanes, as changed, continue to 
meet the applicable provisions of the regulations incorporated by 
reference in Type Certificate No. A16NM 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 specific 
regulations are 14 CFR part 25, as amended by Amendments 25-1 through 
25-108 with exceptions as indicated in the Type Certificate Data Sheet.
    If the Administrator finds that the applicable airworthiness 
regulations (part 25, as amended) do not contain adequate or 
appropriate safety standards for the Gulfstream G150 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 G150 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.
    The FAA issues special conditions, as defined in Sec.  11.19, under 
Sec.  11.38, and they become part of the type certification basis under 
the provisions of Sec.  21.101.

Novel or Unusual Design Features

    As noted earlier, the Gulfstream G150 airplanes modified by 
Gulfstream Aerospace Corporation will incorporate an electronic laser 
inertial reference system that will perform critical functions. This 
system may be vulnerable to high-intensity radiated fields external to 
the airplane. Current airworthiness standards of part 25 do not contain 
adequate or appropriate safety standards for protecting this equipment 
from adverse effects of HIRF. So this system is considered to be a 
novel or unusual design feature.

Discussion

    As previously stated, there is no specific regulation that 
addresses protection for electrical and electronic systems from HIRF. 
Increased power levels from radio frequency 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 Gulfstream G150 airplanes modified by 
Gulfstream Aerospace Corporation. 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 because of HIRF.

High-Intensity Radiated Fields (HIRF)

    High-power radio frequency transmitters for radio, radar, 
television, and satellite communications can adversely affect operation 
of airplane electric and electronic systems. Therefore, the immunity of 
critical avionics/electronics and electrical systems to HIRF must be 
established.
    Based on surveys and an analysis of existing HIRF emitters, an 
adequate level of protection exists when airplane system immunity is 
demonstrated when exposed to the HIRF environments in either paragraph 
1 or 2 below:
    1. A minimum environment of 100 volts rms (root-mean-square) per 
meter electric field strength from 10 KHz to 18 GHz.
    a. System elements and their associated wiring harnesses must be 
exposed to the environment without benefit of airframe shielding.

[[Page 54578]]

    b. Demonstration of this level of protection is established through 
system tests and analysis.
    2. An environment external to the airframe of the field strengths 
shown in the table below for the frequency ranges indicated. Immunity 
to both peak and average field strength components from the table must 
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 environment levels identified above are the result of an FAA 
review of existing studies on the subject of HIRF and of the work of 
the Electromagnetic Effects Harmonization Working Group of the Aviation 
Rulemaking Advisory Committee.

Applicability

    These special conditions are applicable to Gulfstream G150 
airplanes modified by Gulfstream Aerospace Corporation. Should 
Gulfstream Aerospace Corporation apply at a later date for a 
supplemental type certificate to modify any other model included on 
Type Certificate No. A16NM to incorporate the same or similar novel or 
unusual design feature, these special conditions would apply to that 
model as well under provisions of Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
on Gulfstream G150 airplanes modified by Gulfstream Aerospace 
Corporation. 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.

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
Therefore, under the authority delegated to me by the Administrator, 
the following special conditions are issued as part of the supplemental 
type certification basis for the G150 airplanes modified by Gulfstream 
Aerospace Corporation.
    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 continued safe flight and 
landing of the airplane.

    Issued in Renton, Washington, on September 8, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-15401 Filed 9-15-06; 8:45 am]
BILLING CODE 4910-13-P