[Federal Register Volume 68, Number 1 (Thursday, January 2, 2003)]
[Rules and Regulations]
[Pages 3-5]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-33131]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE193, Special Condition 23-133-SC]


Special Conditions: S-TEC Corporation; Various Airplane Models; 
Protection of Systems for 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 to S-TEC Corporation, One 
S-TEC Way Municipal Airport, Mineral Wells, TX 76067, for a 
Supplemental Type Certificate for the models listed under the heading 
``Type Certification Basis.'' These special conditions include various 
airplane models to streamline the certification process as recommended 
from completed Safer Sky Programs. The primary objective of 
streamlining the certification process is to improve the safety of the 
airplane fleet by fostering the incorporation of both new technologies 
that can be certificated affordably under 14 CFR part 23.
    The airplanes will have novel and unusual design features when 
compared to the state of technology envisaged in the applicable 
airworthiness standards. These novel and unusual design features 
include the installation of single or dual Meggitt Avionics Magic 
electronic flight instrument system (EFIS) manufactured by Meggitt 
Avionics, for which the applicable regulations do not contain adequate 
or appropriate airworthiness 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 the airworthiness standards applicable to these 
airplanes.

DATES: The effective date of these special conditions is December 18, 
2002. Comments must be received on or before before February 3, 2003.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. CE193, Room 506, 901 Locust, Kansas City, Missouri 64106. 
All comments must be marked: Docket No. CE193. Comments may be 
inspected in the Rules Docket weekdays, except Federal holidays, 
between 7:30 a.m. and 4:00 p.m.

FOR FURTHER INFORMATION CONTACT: Wes Ryan, Aerospace Engineer, 
Standards Office (ACE-110), Small Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 901 Locust, 
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4127.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the design 
approval 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.

Comments Invited

    Interested persons are invited to submit such written data, views, 
or arguments as they may desire. Communications should identify the 
regulatory docket or notice 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. The 
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 this notice must include a self-
addressed, stamped postcard on which the following statement is made: 
``Comments to Docket No. CE193.'' The postcard will be date stamped and 
returned to the commenter.

Background

    On September 16, 2002, S-TEC Corporation, One S-TEC Way, Mineral 
Wells Airport, Mineral Wells, Texas 76067, made an application to the 
FAA for a new Supplemental Type Certificate for the Raytheon (Beech) 
65-90, 55-A90, 65-A90-1, 65-A90-4, B90, and C90 airplane models. They 
have also identified future STC projects that need the special 
conditions. All models are currently approved under the type

[[Page 4]]

certification basis listed in the paragraph headed ``Type Certification 
Basis.'' The proposed modification incorporates a novel or unusual 
design feature, such as digital avionics consisting of an EFIS that is 
vulnerable to HIRF external to the airplane.

Type Certification Basis

    Under the provisions of 14 CFR part 21, Sec.  21.101, S-TEC 
Corporation must show that affected airplane models, as changed, 
continue to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate Numbers listed below 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'' and can be found in the Type Certificate Numbers 
listed below. In addition, the type certification basis of airplane 
models that embody this modification will include Sec.  23.1301 of 
Amendment 23-20; Sec. Sec.  23.1309, 23.1311, and 23.1321 of Amendment 
23-49; and Sec.  23.1322 of Amendment 23-43; exemptions, if any; and 
the special conditions adopted by this rulemaking action.

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                       Aircraft model                                       Type certificate number
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Raytheon (Beech) 65-90, 65-A90, 65-A90-1, 65-A90-4, B90,      3A20, Rev. 60, 9/10/01
 C90, and E90.
Raytheon (Beech) King Air 200...............................  A24CE, Rev. 82, 4/23/02
Twin Commander Aircraft Corporation 690C, 695, 695A, and      2A4, Rev. 46, 4/3/00
 695B.
Cessna 425 Conquest I.......................................  A7CE, Rev. 45, 7/12/02
Piper PA-31T Cheyenne II....................................  A8EA, Rev. 21, 4/8/98
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Discussion

    If the Administrator finds that the applicable airworthiness 
standards do not contain adequate or appropriate safety standards 
because of novel or unusual design features of an airplane, special 
conditions are prescribed under the provisions of Sec.  21.16.
    Special conditions, as appropriate, as defined in Sec.  11.19, are 
issued in accordance with Sec.  11.38 after public notice and become 
part of the type certification basis in accordance with Sec.  
21.101(b)(2) of Amendment 21-69.
    Special conditions are initially applicable to the model for which 
they are issued. Should the applicant apply for a supplemental type 
certificate to modify any other model already included on the same type 
certificate 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.

Novel or Unusual Design Features

    S-TEC Corporation plans to incorporate certain novel and unusual 
design features into an airplane for which the airworthiness standards 
do not contain adequate or appropriate safety standards for protection 
from the effects of HIRF. These features include EFIS, which are 
susceptible to the HIRF environment, that were not envisaged by the 
existing regulations for this type of airplane.
    Protection of Systems from HIRF: Recent advances in technology have 
given rise to the application in aircraft designs of advanced 
electrical and electronic systems that perform functions required for 
continued safe flight and landing. Due to the use of sensitive solid 
state advanced components in analog and digital electronics circuits, 
these advanced systems are readily responsive to the transient effects 
of induced electrical current and voltage caused by the HIRF. The HIRF 
can degrade electronic systems performance by damaging components or 
upsetting system functions.
    Furthermore, the HIRF environment has undergone a transformation 
that was not foreseen when the current requirements were developed. 
Higher energy levels are radiated from transmitters that are used for 
radar, radio, and television. Also, the number of transmitters has 
increased significantly. There is also uncertainty concerning the 
effectiveness of airframe shielding for HIRF. Furthermore, coupling to 
cockpit-installed equipment through the cockpit window apertures is 
undefined.
    The combined effect of the technological advances in airplane 
design and the changing environment has resulted in an increased level 
of vulnerability of electrical and electronic systems required for the 
continued safe flight and landing of the airplane. Effective measures 
against the effects of exposure to HIRF must be provided by the design 
and installation of these systems. The accepted maximum energy levels 
in which civilian airplane system installations must be capable of 
operating safely are based on surveys and analysis of existing radio 
frequency emitters. These special conditions require that the airplane 
be evaluated under these energy levels for the protection of the 
electronic system and its associated wiring harness. These external 
threat levels, which are lower than previous required values, are 
believed to represent the worst case to which an airplane would be 
exposed in the operating environment.
    These special conditions require qualification of systems that 
perform critical functions, as installed in aircraft, to the defined 
HIRF environment in paragraph 1 or, as an option to a fixed value using 
laboratory tests, in paragraph 2, as follows:
    (1) The applicant may demonstrate that the operation and 
operational capability of the installed electrical and electronic 
systems that perform critical functions are not adversely affected when 
the aircraft is exposed to the HIRF environment defined below:

------------------------------------------------------------------------
                                      Field strength (volts per meter)*
             Frequency             -------------------------------------
                                           Peak             Average
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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

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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 root-mean-square
  (rms) values.


or,

    (2) The applicant may demonstrate by a system test and analysis 
that the electrical and electronic systems that perform critical 
functions can withstand a minimum threat of 100 volts per meter peak 
electrical field strength from 10 kHz to 18 GHz. When using this test 
to show compliance with the HIRF requirements, no credit is given for 
signal attenuation due to installation.
    A preliminary hazard analysis must be performed by the applicant, 
for approval by the FAA, to identify either electrical or electronic 
systems that perform critical functions. The term ``critical'' means 
those functions whose failure would contribute to, or cause, a failure 
condition that would prevent the continued safe flight and landing of 
the airplane. The systems identified by the hazard analysis that 
perform critical functions are candidates for the application of HIRF 
requirements. A system may perform both critical and non-critical 
functions. Primary electronic flight display systems, and their 
associated components, perform critical functions such as attitude, 
altitude, and airspeed indication. The HIRF requirements apply only to 
critical functions.
    Compliance with HIRF requirements may be demonstrated by tests, 
analysis, models, similarity with existing systems, or by any 
combination of these. Service experience alone is not acceptable since 
normal flight operations may not include an exposure to the HIRF 
environment. Reliance on a system with similar design features for 
redundancy as a means of protection against the effects of external 
HIRF is generally insufficient since all elements of a redundant system 
are likely to be exposed to the fields concurrently.

Applicability

    As discussed above, these special conditions are applicable to one 
modification to the airplane models listed under the heading ``Type 
Certification Basis.'' Should S-TEC Corporation apply to extend this 
modification to include additional airplane models, the special 
conditions would extend to these models as well under the provisions of 
Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
of one modification to several models of airplanes. 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 some airplane 
models, 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 23

    Aircraft, Aviation safety, Signs and symbols.

Citation

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, and 44701; 14 CFR part 21, 
Sec. Sec.  21.16 and 21.101; and 14 CFR part 11, Sec. Sec.  11.38 
and 11.19.

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 airplane models listed under the 
``Type Certification Basis'' heading modified by S-TEC Corporation to 
add an EFIS.
    1. Protection of Electrical and Electronic Systems from High 
Intensity Radiated Fields (HIRF). Each system that performs critical 
functions must be designed and installed to ensure that the operations, 
and operational capabilities of these systems to perform critical 
functions, are not adversely affected when the airplane is exposed to 
high intensity radiated electromagnetic fields external to the 
airplane.
    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 Kansas City, Missouri, on December 18, 2002.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 02-33131 Filed 12-31-02; 8:45 am]
BILLING CODE 4910-13-P