[Federal Register Volume 69, Number 113 (Monday, June 14, 2004)]
[Rules and Regulations]
[Pages 32853-32855]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-13311]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM284; Special Conditions No. 25-268-SC]


Special Conditions: Sabreliner Corporation Model NA-265-65; 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 Sabreliner Corporation 
Model NA-265-65 airplanes modified by Garrett Aviation Services. 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 two Honeywell N1 Digital Electronic 
Engine Controls (DEEC) that perform critical functions. 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

[[Page 32854]]

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 June 3, 2004. 
Comments must be received on or before July 14, 2004.

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. NM284, 1601 Lind 
Avenue, SW., Renton, Washington, 98055-4056; or delivered in duplicate 
to the Transport Directorate at the above address. All comments must be 
marked: Docket No. NM284. 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: 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 are impracticable, because these procedures would significantly 
delay certification of the airplane and, thus, delivery of the affected 
airplanes. 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 finds, therefore, 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 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 thru 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 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 December 4, 2003, Garrett Aviation Services, 1200 North Airport 
Drive, Capital Airport Springfield, IL 62707, applied for a 
Supplemental Type Certificate (STC) to modify Sabreliner Corporation 
Model NA-265-65 airplanes approved under Type Certificate No. A2WE. The 
Sabreliner Corporation model NA-265-65 is a transport category 
airplane, powered by two AiResearch Mfg. Co. TFE731-3-1D turbofans. The 
airplane operates with a 2-pilot crew and can hold up to 10 passengers. 
Its maximum takeoff weight is 24,000 pounds.
    The modification incorporates the installation of Honeywell N1 
Digital Electronic Engine Controls (DEEC). The DEEC replaces the 
existing Analog Electronic Engine Control (EEC) and provides additional 
functional capability in the system. The digital avionics/electronics 
and electrical systems to be installed under this project are 
vulnerable to high-intensity radiated fields (HIRF) external to the 
airplane.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Garrett Aviation Services 
must show that the Sabreliner Corporation model NA-265-65 airplanes, as 
changed, continue to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate No. A2WE 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 basis for the modified 
Sabreliner Corporation Model NA-265-65 airplanes include 14 CFR part 
25, dated February 1, 1964, as amended by Amendment 25-1 through 25-20, 
except for special conditions and exceptions noted in Type Certificate 
Data Sheet (TDCS) A2WE.
    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 Sabreliner Corporation 
Model NA-265-65 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 Sabreliner Corporation model NA-265-65 airplanes must 
comply with the noise certification requirement of part 36, including 
Amendment 36-1.
    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(b)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should Garrett Aviation Services 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 14 CFR 21.101(a)(1).

Novel or Unusual Design Features

    The Sabreliner Corporation model NA-265-65 airplanes modified by 
Garrett Aviation Services will incorporate Honeywell N1 Digital 
Electronic Engine Controls (DEEC) which will perform critical 
functions. These systems 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 effect 
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 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 that is equivalent to 
that intended by the regulations incorporated by reference; special 
conditions are needed for Sabreliner Corporation model NA-265-65 
airplanes modified by Garrett Aviation Services. These special 
conditions require that new electrical and

[[Page 32855]]

electronic 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 electrical and electronic 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 (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 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
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 
Sabreliner Corporation Model NA-265-65 airplanes modified by Garret 
Aviation Services. Should Garrett Aviation Services apply at a later 
date for design change approval 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 the Sabreliner Corporation Model NA-265-65 airplanes modified by 
Garrett Aviation Services. 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. 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 record keeping 
requirements.


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

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


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 Sabreliner 
Corporation Model NA-265-65 modified by Garrett Aviation Services.
    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 June 3, 2004.
Franklin Tiangsing,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-13311 Filed 6-10-04; 8:45 am]
BILLING CODE 4910-13-P