[Federal Register Volume 68, Number 131 (Wednesday, July 9, 2003)]
[Rules and Regulations]
[Pages 40757-40759]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17249]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE196; Special Conditions No. 23-136-SC]


Special Conditions: CenTex Aerospace, Inc: Raytheon/Beech Model 
58, Installation of Full Authority Digital Engine Control (FADEC) 
System 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 to CenTex Aerospace, Inc.: 
7805 Karl May Drive; Waco, Texas 76708 for modifications to the 
Raytheon/Beech Model 58 airplane. The airplanes, modified by CenTex, 
will have a novel or unusual design feature(s) associated with the 
installation of engines that use an electronic engine control system in 
place of the engine's mechanical system. 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: June 9, 2003.
    Comments must be received on or before August 8, 2003.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration (FAA), Regional Counsel, ACE-7, 
Attention: Rules Docket, Docket No. CE196, 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. CE196. 
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: Wes Ryan, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: 816-329-4127, 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

    Interested persons are invited to submit such written data, views, 
or arguments as they may desire. Communications should identify the 
regulatory docket or special condition 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. CE196.'' The postcard will be date stamped and 
returned to the commenter.

Background

    On December 9, 2002, CenTex Aerospace applied for a Supplemental 
Type Certificate to modify the Raytheon/Beech Model 58. The modified 
Model 58 Baron will be powered by two reciprocating engines equipped 
with electronic engine control systems with full authority capability 
in place of the hydromechanical control systems.

Type Certification Basis

    Under the provisions of 14 CFR part 21, Sec.  21.17, CenTex 
Aerospace must show that the modified Model 58 Baron meets the 
applicable provisions of the original certification basis of the Model 
58, as listed on Type Certificate No. 3A16 issued June 18, 1957; 
exemptions, if any; and the special conditions adopted by this 
rulemaking action. The model 58 was originally certified under CAR 3, 
as amended to May 15, 1956, and Paragraphs 23.1385(c), 23.1387(a) and 
23.1387(e) of FAR Part 23 as amended by Amendment 23-12. Noise

[[Page 40758]]

certification under FAR Part 36, Amendment 36-10 for Model 58 S/N TH-
1090 and after with applicable equivalent safety findings: CAR 3.387 
for Model 58 and 58A (all serials). For Models 58 and 58A, S/N TH-1 
through TH-1471, TH-1476, TH-1487, TH-1489, TH-1498 equipped per Beech 
Kit Dwg. 58-5012 or Models 58 and 58A, TH-1472 through TH-1475, TH-1477 
through TH-1486, TH-1488, TH-1497, TH-1499 and after, equipped per 
Beech Dwg. 58-000059 or Beech Kit Dwg. 58-5012, compliance with ice 
protection has been demonstrated with FAR 23.775 of Amendment 23-7; 
23.773, 23.929 and 23.1419 of Amendment 23-14; 23.1309 of Amendment 23-
17; 23.1325, 23.1327, 23.1351, 23.1357 and 23.1547(e) of Amendment 23-
20; 23.1416, 23.1559 and 23.1583(h) of Amendment 23-23 and 25.1323(e) 
of FAR 25 dated February 1, 1965.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 23) do not contain adequate or 
appropriate safety standards for the modified Model 58 Baron because of 
a novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    Special conditions, as appropriate, as defined in 11.19, are issued 
in accordance with Sec.  11.38, and become part of the certification 
basis for the supplemental 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 supplemental type 
certificate be amended in the future to include other models that are 
listed on the same type data sheet and incorporate the same novel or 
unusual design features, the special conditions would also apply under 
the provisions of Sec.  21.101(a)(1).

Novel or Unusual Design Features

    The Raytheon/Beech Model 58 Baron, modified by CenTex, Inc., will 
incorporate the following novel or unusual design features:
    The Raytheon/Beech Model 58 Baron airplane modified by CenTex, 
Inc., will use 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 modified Raytheon/Beech 
Model 58 Baron 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, 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 proposed for the CenTex modified 
Raytheon/Beech Model 58 Baron airplane to provide HIRF protection and 
to evaluate the installation of the electronic engine control system 
for compliance with the requirements of Sec.  23.1309(a) through (e) at 
Amendment 23-49.

Applicability

    As discussed above, these special conditions are applicable to 
Model 58 Barons modified by CenTex, Inc. Should CenTex Aerospace apply 
at a later date to amend the supplemental type certificate to 
incorporate the same novel or unusual design features on another model 
listed on the same type certificate data sheet as the Model 58 Baron, 
the special conditions would apply to that model under the provisions 
of Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
on one model, the Model 58 Baron, of airplane. It is not a rule of 
general applicability, and it affects only the applicant who applied to 
the FAA for approval of these features on the airplane.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register. However the FAA finds that good cause exists to make 
these special conditions effective upon issuance.

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

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the supplemental type certification basis for Raytheon/Beech Model 58 
Baron airplanes modified by CenTex, Inc.
    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

[[Page 40759]]

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
                       Frequency                             meter)
                                                       -----------------
                                                         Peake     Avg.
------------------------------------------------------------------------
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.
    2. Electronic Engine Control System. The installation of the 
electronic engine control system must comply with the requirements of 
Sec.  23.1309(a) through (e) at Amendment 23-46. The intent of this 
requirement is not to re-evaluate the inherent hardware reliability of 
the control itself, but rather determine the effects, including 
environmental effects addressed in Sec.  23.1309(e), on the airplane 
systems and engine control system when installing the control on the 
airplane. When appropriate, engine certification data may be used when 
showing compliance with this requirement.

    Issued in Kansas City, Missouri on June 9, 2003.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-17249 Filed 7-8-03; 8:45 am]
BILLING CODE 4910-13-P