[Federal Register Volume 63, Number 146 (Thursday, July 30, 1998)]
[Rules and Regulations]
[Pages 40638-40640]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20345]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE146, Special Condition 23-98-02-SC]


Special Conditions; Raytheon Aircraft Company, Beech Model 3000 
Airplane: Protection of Systems From 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 Raytheon Aircraft 
Company, 9709 East Central, Wichita, Kansas 67201-0085 for a Type 
Certificate on the Beech Model 3000 airplane. This airplane 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 
electronic displays 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 that provided by the existing 
airworthiness standards.

DATES: The effective date of these special conditions is July 14, 1998.
    Comments must be received on or before August 31, 1998 for 
domestic, November 27, 1998 for foreign.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Office of the Assistant Chief Counsel, ACE-7, 
Attention: Rules Docket Clerk, Docket No. CE146, Room 1558, 601 East 
12th Street, Kansas City, Missouri 64106. All comments must be marked: 
Docket No. CE146. 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: Ervin Dvorak, Aerospace Engineer, 
Standards Office (ACE-110), Small Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 601 East 12th 
Street, Kansas City, Missouri 64106; telephone (816) 426-6941.

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 approval 
design 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 CE146.'' The postcard will be date stamped and returned 
to the commenter.

Background

    Beech Aircraft Corporation made application for a new type 
certification (TC) for the Beech Model 3000 airplane on August 31, 
1992, for the purpose of entering the competition with several other 
manufacturers for the contract to build the Joint Primary Aircraft 
Training System (JPATS) trainer aircraft. This application was allowed 
to expire after three years when it was determined that

[[Page 40639]]

Beech Aircraft Corporation did not need a TC in their name to be in the 
competition. The Swiss TC for the original Pilatus PC-9 airframe was 
adequate for that purpose.
    Beech made a new application for a TC on January 15, 1996, when 
they were awarded the contract. This is the application that is still 
in force. On April 15, 1996, Beech Aircraft Corporation became Raytheon 
Aircraft Company.
    The proposed configuration incorporates a novel or unusual design 
feature, such as digital avionics consisting of an electronic flight 
instrument system (EFIS), that is vulnerable to HIRF external to the 
airplane.

Type Certification Basis

    Under the provisions of 14 CFR part 21, 21.17, Raytheon Aircraft 
Company must show that the Beech Model 3000 meets the applicable 
provisions of the following:
    The type certification basis for the Beech Model 3000 airplane is 
given by the following:
    Federal Aviation Regulations part 23 effective February 1, 1965, as 
amended by Amendments 23-1 through 23-47; Federal Aviation Regulations 
Secs. 23.201, 23.203 and 23.207 as amended by Amendment 23-50; Federal 
Aviation Regulations part 34 effective September 10, 1990, as amended 
by the amendment in effect on the date of certification; Federal 
Aviation Regulations part 36 effective December 1, 1969, as amended by 
amendment 36-1 through the amendment in effect on the day of 
certification; The Noise Control Act of 1972; and Special Conditions 
for such items as Protection from High Intensity Radiated Fields 
(HIRF), Digital Electronic Engine Control (DEEC) and the Section Defuel 
System.
    If the Administrator finds that the applicable airworthiness 
regulations, 14 CFR part 23, do not contain adequate or appropriate 
safety standards for the Beech Model 3000 because of a novel or unusual 
design feature, special conditions are prescribed under the provisions 
of Sec. 21.16.
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.49, as required by Secs. 11.28 and 11.29(b), and become part of 
the type certification basis in accordance with Sec. 21.17(a)(2).
    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, the special conditions would also apply to the 
other model under the provisions of Sec. 21.101(a)(1).

Novel or Unusual Design Features

    The Beech Model 3000 will incorporate the following novel or 
unusual design features: Installation of electronic equipment and 
displays for which the airworthiness standards do not contain adequate 
or appropriate safety standards for protection from the effects of 
HIRF.

Discussion

    The FAA may issue and amend special conditions, as necessary, as 
part of the type certification basis if the Administrator finds that 
the airworthiness standards, designated according to Sec. 21.101(b), 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 to establish a level of 
safety equivalent to that established in the regulations. Special 
conditions are normally issued according to Sec. 11.49, after public 
notice, as required by Secs. 11.28 and 11.29(b), effective October 14, 
1980, and become a part of the type certification basis in accordance 
with Sec. 21.101(b)(2).
    Raytheon Aircraft Company 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 electronic 
systems, which are susceptible to the HIRF environment, that were not 
envisaged by the existing regulations for this type of airplane.

Protection of Systems From High Intensity Radiated Fields (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 previously 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 as follows:

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

[[Page 40640]]

                                                                        
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 electrical and/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 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 the 
Beech Model 3000. Should Raytheon Aircraft Company apply at a later 
date for a supplemental type certificate or amended type certificate to 
modify any other model that may be included on this Type Certificate 
incorporating, the same novel or unusual design feature, the 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 one model of airplane. 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 23

    Aircraft, Aviation safety, Signs and symbol

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, 
Secs. 21.16 and 21.17; and 14 CFR part 11, Secs. 11.28 and 11.49.

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 the Raytheon Aircraft Company, Beech 
Model 3000 airplane.
    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 July 14, 1998.
Marvin Nuss,
Assistant Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-20345 Filed 7-29-98; 8:45 am]
BILLING CODE 4910-13-P