[Federal Register Volume 72, Number 149 (Friday, August 3, 2007)]
[Rules and Regulations]
[Pages 43137-43139]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-14935]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE272; Special Conditions No. 23-212-SC]


Special Conditions: Centex Aerospace Inc., Cirrus Design 
Corporation Model SR22; Installation of a Full Authority Digital Engine 
Control (FADEC) Engine and the Protection of the System From the 
Effects of 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 for the Centex Aerospace 
Inc. modified Cirrus Design Corporation Model SR22. This airplane as 
modified by Centex Aerospace Inc. will have a novel or unusual design 
feature(s) associated with the installation of a full authority digital 
engine control (FADEC) engine. The applicable airworthiness regulations 
do not contain adequate or appropriate safety standards for this design 
feature. 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.

DATES: The effective date of these special conditions is July 26, 2007. 
Comments must be received on or before September 4, 2007.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration (FAA), Regional Counsel, ACE-7, Attention: Rules Docket, 
Docket No. CE272, 901 Locust, Room 506, Kansas City, Missouri 64106, or 
delivered in duplicate to the Regional Counsel at the above address. 
Comments must be marked: Docket No. CE272. 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: Peter L. Rouse, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: 816-329-4135, fax: 816-329-4090.

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

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. 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 
about these special conditions. You can inspect the docket 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 by 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 based on the comments we receive.
    If you want us to let you know we received your comments on these 
special conditions, send us 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 March 15, 2004, Centex Aerospace, Inc. applied for a 
supplemental type certificate for the Cirrus Model SR22 to install a 
full authority digital engine control in the Cirrus Model SR22. CenTex 
Aerospace, Inc. plans to install a Teledyne Continental Motors model 
IOF-550-N engine in the Cirrus Design Corporation Model SR-22 airplane. 
This type certified engine, approved under FAA Type Certificate E3SO; 
Revision 7, dated

[[Page 43138]]

February 4, 2002, incorporates Full Authority Digital Electronic 
Controls (FADEC) fuel and ignition control system. Even though the 
engine control system is certificated as part of the engine and does 
not interface or share data with any of the airplane systems, the 
installation of an engine with an electronic control system requires 
evaluation due to critical environmental effects and possible effects 
on or by other airplane systems. For example, indirect effects of 
lightning, radio interference with other airplane electronic systems, 
shared engine and airplane data and power sources.
    The Cirrus Model SR22 is currently approved under Type Certificate 
No. A00009CH. The Cirrus Model SR22 is a 3,400 pound single-engine, 
four-place, fixed-gear airplane powered by a 310 hp reciprocating 
engine. It has a conventional tractor configuration and uses composites 
for the structure. Some unique features of the SR-22 include sidestick 
controls and a ballistic recovery system, and a single combination 
throttle/propeller control lever.

Type Certification Basis

    Under the provisions of Sec.  21.101, Centex Aerospace, Inc. must 
show that the Cirrus Model SR22, as changed, continues to meet the 
applicable provisions of the regulations incorporated by reference in 
Type Certificate No. A00009CH, 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.'' The regulations incorporated by 
reference in Type Certificate No. A00009CH are as follows:

Model SR22: Part 23 of the Federal Aviation Regulations effective 
February 1, 1965, as amended by 23-1 through 23-53, except as follows:
    23.301 through Amendment 47
    23.855, 23.1326, 23.1359, not applicable
    Federal Aviation Regulation 36, dated December 1, 1969, as amended 
by current amendment as of the date of type Certification.
Equivalent Safety Items:
    Equivalent Levels of Safety finding (ACE-96-5) made per the 
provisions of 14 CFR part 23, Sec.  23.221; Refer to FAA ELOS letter 
dated June 10, 1998 for models SR20, SR22.
    Equivalent Levels of Safety finding (ACE-00-09) made per the 
provisions of 14 CFR part 23, Sec. Sec.  23.1143(g) and 23.1147(b); 
Refer to FAA ELOS letter dated September 11, 2000 for model SR22.
Special Conditions:
    23-ACE-88 for ballistic parachute.
    23-134-SC for protection of systems for High Intensity Radiated 
Fields (HIRF).
    23-163-SC for inflatable restraint system.

    In addition, if the regulations incorporated by reference do not 
provide adequate standards regarding the change, the applicant must 
comply with certain regulations in effect on the date of application 
for the change.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 23, Sec.  23.1309) do not contain 
adequate or appropriate safety standards for the Model SR22 because of 
a novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    The FAA issues special conditions, as defined in Sec.  11.19, under 
Sec.  11.38 and they become part of the type certification basis under 
Sec.  21.101.
    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 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.

Novel or Unusual Design Features

    The Centex Aerospace Inc. modified Cirrus Model SR22 will 
incorporate the following novel or unusual design features:
    An engine that includes an electronic control system with Full 
Authority Digital Engine control (FADEC) capability.
    Many advanced electronic systems are prone to either upsets or 
damage, or both, at energy levels lower than analog systems. The 
increasing use of high power radio frequency emitters mandates 
requirements for improved high intensity radiated fields (HIRF) 
protection for electrical and electronic equipment. Since the 
electronic engine control system used on the Centex Aerospace, Inc. 
modified Cirrus Design Corporation Model SR22 will perform critical 
functions, provisions for protection from the effects of HIRF should be 
considered and, if necessary, incorporated into the airplane design 
data. The FAA policy contained in Notice 8110.71, dated April 2, 1998, 
establishes the HIRF energy levels that airplanes will be exposed to in 
service. The guidelines set forth in this notice are the result of an 
Aircraft Certification Service review of existing policy on HIRF, in 
light of the ongoing work of the Aviation Rulemaking Advisory Committee 
(ARAC) Electromagnetic Effects Harmonization Working Group (EEHWG). The 
EEHWG adopted a set of HIRF environment levels in November 1997 that 
were agreed upon by the FAA, the Joint Aviation Authorities (JAA), and 
industry participants. As a result, the HIRF environments in this 
notice reflect the environment levels recommended by this working 
group. This notice states that a FADEC is an example of a system that 
should address the HIRF environments.
    Even though the control system will be certificated as part of the 
engine, the installation of an engine with an electronic control system 
requires evaluation due to the possible effects on or by other airplane 
systems (e.g., radio interference with other airplane electronic 
systems, shared engine and airplane power sources). The regulatory 
requirements in 14 CFR part 23 for evaluating the installation of 
complex systems, including electronic systems, are contained in Sec.  
23.1309. However, when Sec.  23.1309 was developed, the use of 
electronic control systems for engines was not envisioned; therefore, 
the Sec.  23.1309 requirements were not applicable to systems 
certificated as part of the engine (reference Sec.  23.1309(f)(1)). 
Also, electronic control systems often require inputs from airplane 
data and power sources and outputs to other airplane systems (e.g., 
automated cockpit powerplant controls such as mixture setting). 
Although the parts of the system that are not certificated with the 
engine could be evaluated using the criteria of Sec.  23.1309, the 
integral nature of systems such as these makes it unfeasible to 
evaluate the airplane portion of the system without including the 
engine portion of the system. However, Sec.  23.1309(f)(1) again 
prevents complete evaluation of the installed airplane system since 
evaluation of the engine system's effects is not required.
    Therefore, special conditions are issued for the Centex Aerospace, 
Inc. modified Cirrus Design Corporation Model SR22 to provide HIRF 
protection.

Applicability

    As discussed above, these special conditions are applicable to the 
Centex Aerospace, Inc. modified Cirrus Design Corporation Model SR22. 
Should Centex Aerospace, Inc. apply at a later date for a supplemental 
type certificate to modify any other model included on Type Certificate 
No. A00009CH, to incorporate the same novel or unusual

[[Page 43139]]

design feature, the special conditions would apply to that model as 
well.

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. Therefore, 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.

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 Centex Aerospace, Inc. modified 
Cirrus Design Corporation Model SR22.
    1. High Intensity Radiated Fields (HIRF) Protection. In showing 
compliance with 14 CFR part 21 and the airworthiness requirements of 14 
CFR part 23, protection against hazards caused by exposure to HIRF 
fields for the full authority digital engine control system, which 
performs critical functions, must be considered. To prevent this 
occurrence, the electronic engine control system must be designed and 
installed to ensure that the operation and operational capabilities of 
this critical system are not adversely affected when the airplane is 
exposed to high energy radio fields.
    At this time, the FAA and other airworthiness authorities are 
unable to precisely define or control the HIRF energy level to which 
the airplane will be exposed in service; therefore, the FAA hereby 
defines two acceptable interim methods for complying with the 
requirement for protection of systems that perform critical functions.
    (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 external HIRF threat environment defined 
in the following table:

------------------------------------------------------------------------
                                                       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 strength, without the benefit of airplane structural 
shielding, in the frequency range of 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. Data used for engine 
certification may be used, when appropriate, for airplane 
certification.

    Issued in Kansas City, Missouri on July 26, 2007.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-14935 Filed 8-2-07; 8:45 am]
BILLING CODE 4910-13-P