[Federal Register Volume 70, Number 125 (Thursday, June 30, 2005)]
[Rules and Regulations]
[Pages 37656-37659]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-12882]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. 228, Special Condition 23-167-SC]


Special Conditions; Diamond Aircraft Industries, EFIS and Full 
Authority Digital Engine Control (FADEC) on the Diamond DA-42; 
Protection of Systems for 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 Diamond Aircraft 
Industries GmbH, N.A. Otto-Strasse 5, A-2700 Wiener Neistadt, Austria; 
telephone: 43 2622 26 700; facsimile: 43 2622 26 780, as part of the 
FAA Type Validation of the Diamond Aircraft Industries Model DA-42. 
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 a Garmin Model G-1000 electronic flight instrument 
system (EFIS) display, and digital engine controls. 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

[[Page 37657]]

equivalent to the airworthiness standards applicable to these 
airplanes.

DATES: The effective date of these special conditions is June 22, 2005. 
Comments must be received on or before August 1, 2005.

ADDRESSES: Comments may be mailed in duplicate to: Federal Aviation 
Administration, Regional Counsel, ACE-7, Attention: Rules Docket Clerk, 
Docket No. 228, Room 506, 901 Locust, Kansas City, Missouri 64106. All 
comments must be marked: Docket No. 228. 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, Aerospace Engineer, 
Standards Office (ACE-110), Small Airplane Directorate, Aircraft 
Certification Service, Federal Aviation Administration, 901 Locust, 
Room 301, Kansas City, Missouri 64106; telephone (816) 329-4127.

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 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 Docket No. 228.'' The postcard will be date stamped and 
returned to the commenter.

Background

    Diamond Aircraft Industries (DAI) made application through European 
Aviation Safety Agency (EASA) for U.S. Type Certification for the 
Diamond Aircraft Model DA-42 on August 2, 2004. The Diamond DA-42 
aircraft is a new fully composite, four place, twin-engine airplane 
with retractable gear, cantilever low wing and T-tail. The airplane was 
certified by EASA and listed on Type Certificate No. A005 dated May 13, 
2004. Certification work was delegated to the Austrian Civil Authority 
as the JAA/Primary Certification Authority. The airplane is powered by 
two Thielert Aircraft Engines GmbH (Thielert) TAE 125-01 aircraft 
diesel engines (ADE). They are listed on U.S. engine TC No. E00069EN 
and incorporate two MT-propeller, MTV-6-A-C-F/CF187-129, U.S. TC No. 
P19NE. The fuel to be used for the Thielert TAE 125-01 aircraft diesel 
engine in USA is Jet A only. The Type Certification sought is for Day 
VFR/IFR operations.
    As part of the FAA validation process for issuance of a Type 
Certificate in the United States for foreign applicants, the FAA is 
issuing these special conditions to address Certification Review Items 
(CRI) for novel and unusual features of the Diamond DA-42. The proposed 
type design incorporates novel or unusual design features, including 
the Garmin G1000 EFIS system, and digital engine controls that are 
vulnerable to HIRF external to the airplane.

Type Certification Basis

    Based on the provisions of 14 CFR 21.17(c), 21.29 and the Austria-
US BAA, and the FAA Order 8100.14, Interim Procedures for Working with 
the European Community on Airworthiness Certification and Continued 
Airworthiness and the Type Validation principles, the following 
airworthiness requirements are applicable to this project, and will 
remain active for three years from the date of application: The 
certification basis is based on the EASA/ACG certification basis as 
presented in CRI A-01, Issue 4, Joint Certification Basis and is 
harmonized at JAA JAR 23 Amendment 1, which is harmonized at 14 CFR 
part 23 Amendment 51. The FAA identified FAR/EASA Significant Standards 
Differences (SSDs), documented in our CRIs for the validation.
    The Garmin G1000 was originally approved at part 23 Amendment 49 
for Sec.  23.1301, Sec.  23.1309, Sec.  23.1311, Sec.  23.1322, and 
other applicable rules for electronic displays, but is approved at 
Amendment 51 for this installation. The digital engine control was 
certified under part 33 and Amendment 20 with the engine, but is 
approved at part 23 Amendment 51 with the rest of the DA-42 for Sec.  
23.1309 and other applicable regulations for this installation. The 
certification basis also includes any applicable exemptions, equivalent 
levels of safety, and the terms of these special conditions.

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.

Novel or Unusual Design Features

    Diamond Aircraft, Inc. plans to incorporate certain novel and 
unusual design features into the Diamond DA-42 airplane for which the 
airworthiness standards do not contain adequate or appropriate safety 
standards for protection from the effects of HIRF. These features 
include the G1000 EFIS and two digital engine controls, which are 
susceptible to the HIRF environment and were not envisaged by the 
existing regulations for this type of airplane. Though the digital 
engine control systems were initially certificated to 14 CFR part 33, 
the regulatory requirements in 14 CFR part 23 for evaluating the 
installation of complex systems, including electronic systems, are 
contained in Sec.  23.1309.
    When Sec.  23.1309 was developed, the use of electronic control 
systems for engines was not envisioned. The Sec.  23.1309 requirements 
were originally not applied to systems certificated as part of an 
approved engine (Sec.  23.1309(f)(1)). Also, Sec.  23.1309(f)(1) 
implies evaluation of the engine system's effects is not required. 
However, the installation specifics of the electronic engine control 
systems on

[[Page 37658]]

the DA-42 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) using 
Sec.  23.1309. The integral nature of these systems makes it unfeasible 
to evaluate the airplane portion of the system without including the 
engine portion of the system. 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). Therefore, special conditions are proposed to 
provide HIRF protection for the EFIS and digital engine controls and to 
evaluate the installation for compliance with the requirements of Sec.  
23.1309(a) through (e) at Amendment 23-51 for the Diamond DA-42.

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:
    (2) 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, 
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

[[Page 37659]]

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 
Diamond DA-42 airplane. Should Diamond Aircraft, 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:

PART 23--[AMENDED]

    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 type validation basis for the Diamond DA-42 airplane with a Garmin 
G1000 EFIS and digital engine control systems.
    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. 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 23-51. 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.
    3. 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 June 22, 2005.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-12882 Filed 6-29-05; 8:45 am]
BILLING CODE 4910-13-P