[Federal Register Volume 64, Number 27 (Wednesday, February 10, 1999)]
[Rules and Regulations]
[Pages 6510-6512]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3290]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE151, Special Condition 23-095-SC]


Special Conditions; Jetcruzer Model 500 Airplane

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued to Advanced Aerodynamics & 
Structures, Incorporated (AASI), 3501 Lakewood Blvd., Long Beach 
Airport, California 90808, for an Amended Type Certificate for the 
Jetcruzer Model 500 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 flight instrument 
system (EFIS) 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 the airworthiness standards applicable to 
these airplanes.

EFFECTIVE DATE: The effective date of these special conditions is 
January 29, 1999.
    Comments must be received on or before March 12, 1998.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. CE151, Room 1558, 601 East 12th Street, Kansas City, 
Missouri 64106. All comments must be marked: Docket No. CE151. 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 insurance 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 CE151.'' The postcard will be date stamped and returned 
to the commenter.

Background

    On October 7, 1996, Advanced Aerodynamics & Structures, 
Incorporated, 3501 Lakewood Blvd., Long Beach Airport, CA 90808, made 
an

[[Page 6511]]

application to the FAA for an Amendment to Type Certificate No. A49NM 
to include the Jetcruzer Model 500 airplane. The Jetcruzer model 500 is 
a derivative of the Model 450 currently approved under TC No. A49NM. 
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, Advanced 
Aerodynamics & Structures, Incorporated must show that the Jetcruzer 
Model 500 meets the regulations incorporated by reference in TC No. 
A49NM, which are the following provisions, or the applicable 
regulations in effect on the date of application for the change to the 
Jetcruzer Model 500:
    Federal Aviation Regulations part 23 effective February 1, 1965, as 
amended by Amendments 23-1 through 23-52; 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; exemptions, if any; and the special conditions adopted by this 
rulemaking action.

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 to 
establish a level of safety equivalent to that established in the 
regulations.
    Special conditions are normally issued in accordance with 
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. 21.191(b)(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, 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).

Novel or Unusual Design Features

    Advanced Aerodynamics & Structures, Incorporated 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 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 systems 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
------------------------------------------------------------------------
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 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

[[Page 6512]]

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 
Advanced Aerodynamics & Structures, Incorporated Jetcruzer Model 500. 
Should Advanced Aerodynamics & Structures, Incorporated apply at a 
later date for a change to the type certificate to include any other 
model 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 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, 
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 Advanced Aerodynamics & 
Structures, Incorporated Jetcruzer Model 500 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 January 29, 1999.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-3290 Filed 2-9-99; 8:45 am]
BILLING CODE 4910-13-M