[Federal Register Volume 72, Number 138 (Thursday, July 19, 2007)]
[Rules and Regulations]
[Pages 39555-39557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-14050]



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  Federal Register / Vol. 72, No. 138 / Thursday, July 19, 2007 / Rules 
and Regulations  

[[Page 39555]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE271, Special Condition 23-211-SC]


Special Conditions; Symphony Aircraft Industries, Inc. Model 
SA160; Protection of Systems for High Intensity Radiated Fields (HIRF)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued to Symphony Aircraft 
Industries, Inc. for a type design change to the SA160 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 
(Entegra Avionics Suite) manufactured by Avidyne Corporation 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 July 6, 2007. 
Comments must be received on or before August 20, 2007.

ADDRESSES: Mail two copies of your comments to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. CE271, Room 506, 901 Locust, Kansas City, Missouri 64106. 
All comments must be marked: Docket No. CE271. You may inspect comments 
in the Rules Docket weekdays, except Federal holidays, between 7:30 
a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Jim Brady, Aerospace Engineer, 
Standards Office (ACE-111), Small Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 901 Locust, 
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4132.

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

    We invite interested persons to take part in this rulemaking by 
sending written data, views, or comments. Identify the regulatory 
docket or notice number and submit two copies to the address specified 
above. The most helpful comments reference a specific portion of the 
special conditions, explain the reason for any recommended change, and 
include supporting data.
    We will file in the docket all comments we receive on or before the 
closing date as well as a report summarizing each substantive public 
contact with FAA personnel about these special conditions. All comments 
received will be available in the Rules Docket for examination by 
interested persons, both before and after the closing date for 
comments.
    We will consider all comments we receive by the closing date for 
comments. We will consider comments filed late if it is possible to do 
so without incurring expense or delay. Based on the comments we 
receive, we may change these special conditions.
    If you want the FAA to acknowledge receipt of your comments, 
include a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket No. CE271.'' The postcard will 
be date stamped and we will mail it back to you.

Background

    On November 11, 2006, Symphony Aircraft Industries, Inc. applied to 
the FAA for a type design change to the SA160 airplane. The Symphony 
Aircraft SA160 is currently approved under TC No. A46CE. 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, Symphony 
Aircraft Industries, Inc. must show that the SA160 aircraft design 
change meets the following provisions, or the applicable regulations in 
effect on the date of application for the change to the project: Cert 
basis, 14 CFR part 23 effective February 1, 1965, including Amendments 
23-1 through 23-53; 14 CFR part 36 effective November 18, 1969, 
including Amendments 36-1 through 36-22; as applicable, and 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.

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).
    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.

[[Page 39556]]

Novel or Unusual Design Features

    Symphony Aircraft Industries, Inc. 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 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
------------------------------------------------------------------------
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 
rms, 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 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 
SA160 Avidyne Entegra Avionics Suite project. Should Symphony Aircraft 
Industries, Inc. apply at a later date for a supplemental type 
certificate to modify any other model on the same type certificate to 
incorporate the same novel or unusual design feature, the special 
conditions would apply to that model as well under the provisions of 
Sec.  21.101.

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

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

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

[[Page 39557]]

The Special Conditions

0
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 SA160 Avidyne Entegra Avionics Suite 
Project airplane modified by Symphony Aircraft Industries, Inc. 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 July 6, 2007.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-14050 Filed 7-18-07; 8:45 am]
BILLING CODE 4910-13-P