[Federal Register Volume 67, Number 219 (Wednesday, November 13, 2002)]
[Rules and Regulations]
[Pages 68753-68755]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-28824]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 Prices of new books are listed in the first FEDERAL REGISTER issue of each 
 week.
 
 ========================================================================
 

  Federal Register / Vol. 67, No. 219 / Wednesday, November 13, 2002 / 
Rules and Regulations  

[[Page 68753]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM239; Special Conditions No. 25-223-SC


Special Conditions: Embraer Model 170-100 and 170-200 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 the Embraer Model 170-
100 and 170-200 airplanes. These airplanes will have novel or unusual 
design features when compared to the state of technology envisioned in 
the airworthiness standards for transport category airplanes. The 
airplane design includes an electronic flight control system as well as 
advanced avionics for the display and control of critical airplane 
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 Administrator considers necessary to establish a level of safety 
equivalent to that established by the existing airworthiness standards. 
Additional special conditions will be issued for other novel or unusual 
design features of Embraer Model 170-100 and 170-200 airplanes.

DATES: The effective date of these special conditions is November 1, 
2002. Comments must be received on or before December 13, 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. NM239, 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. NM239. 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: Tom Groves, FAA, International Branch, 
ANM-116, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone 
(425) 227-1503; facsimile (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA has determined that notice and opportunity for prior public 
comment hereon is unnecessary as 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 such written 
comments, data, or views, as they may desire. 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 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 May 20, 1999, Embraer applied for a type certificate for its new 
Model 170 airplane. Two basic versions of the Model 170 are included in 
the application. The Model 170-100 airplane is a 69-78 passenger twin-
engine regional jet with a maximum takeoff weight of 81,240 pounds. The 
Model 170-200 is a lengthened fuselage derivative of the 170-100. 
Passenger capacity for the Model 170-200 is increased to 86, and 
maximum takeoff weight is increased to 85,960 pounds. Embraer Model 
170-100 and 170-200 airplanes will include an electronic flight control 
system as well as advanced avionics for the display and control of 
critical airplane functions. These systems may be vulnerable to high-
intensity radiated fields (HIRF) external to the airplane.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Embraer must show that Model 
170-100 and 170-200 airplanes meet the applicable provisions of 14 CFR 
part 25, as amended by Amendments 25-1 through 25-98.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25, as amended) do not contain adequate or 
appropriate safety standards for Embraer Model 170-100 and 170-200 
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, Embraer Model 170-100 and 170-200 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, and the FAA 
must issue a finding of regulatory adequacy pursuant to Sec.  611 of 
Pub. L. 93-574, the ``Noise Control Act of 1972.''
    Special conditions, as defined in 14 CFR 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), Amendment 
21-69, effective September 16, 1991.

[[Page 68754]]

    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same novel or 
unusual design feature, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, the special conditions would also apply to the 
other model under the provisions of Sec.  21.101(a)(1), Amendment 21-
69, effective September 16, 1991.

Novel or Unusual Design Features

    As noted earlier, Embraer Model 170-100 and 170-200 airplanes will 
include an electronic flight control system as well as advanced 
avionics for the display and control of critical airplane 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 that 
address the protection of this equipment from the adverse effects of 
HIRF. Accordingly, these systems are considered to be novel or unusual 
design features.

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 Embraer Model 170-100 and 170-200 
airplanes. These special conditions require that 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 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 are to be 
demonstrated.

------------------------------------------------------------------------
                                                       Field strength
                                                      (volts per meter)
                     Frequency                     ---------------------
                                                       Peak     Average
------------------------------------------------------------------------
10 kHz-100kHz.....................................         50         50
100 kHz-500 kHz...................................         50         50
500 kHz-2 MHz.....................................         50         50
2 MHz 2-30 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 the 
Embraer Model 170-100 and 170-200 airplanes. Should Embraer apply at a 
later date for a change to the type certificate to include another 
model incorporating 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)(2), Amendment 21-69, effective September 
16, 1991.

Conclusion

    This action affects only certain novel or unusual design features 
of the Embraer Model 170-100 and 170-200 airplanes. It is not a rule of 
general applicability, and it affects only the applicant which 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 procedure in several prior instances and has been 
derived without substantive change from those previously issued. The 
FAA has determined that prior public notice and comment are 
unnecessary, and that 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 type certification basis for Embraer Model 170-100 and 170-200 
airplanes.
    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.


[[Page 68755]]


    Issued in Renton, Washington, on November 1, 2002.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-28824 Filed 11-12-02; 8:45 am]
BILLING CODE 4910-13-P