Special Conditions:
Federal Register Volume 76, Number 173 (Wednesday, September 7, 2011)
Proposed Rules
Pages 55293-55296
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
FR Doc No: 2011-22890
Page 55293
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration 14 CFR Part 23
Docket No. CE313; Notice No. 23-10-03-SC
Special Conditions: Diamond Aircraft Industries, Model DA-40NG;
Electronic Engine Control (EEC) System
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
SUMMARY: This notice proposes special conditions for the Diamond
Aircraft Industries (DAI), model DA-40NG airplane. This airplane will have a novel or unusual design feature(s) associated with an electronic engine control (EEC), also known as a Full Authority Digital Engine
Control (FADEC). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed 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: Comments must be received on or before October 7, 2011.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Regional Counsel, ACE-7, Attention:
Rules Docket, Docket No. CE313, 901 Locust, Room 506, Kansas City,
Missouri 64106, or delivered in duplicate to the Regional Counsel at the above address. Comments must be marked: CE313. 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: Pete Rouse, Federal Aviation
Administration, Aircraft Certification Service, Small Airplane
Directorate, ACE-111, 901 Locust, Kansas City, Missouri, 816-329-4135, fax 816-329-4090.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of these proposed special conditions by submitting 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 proposals described in this notice 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. Persons wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must include with those comments a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. CE313.'' The postcard will be date stamped and returned to the commenter.
Background
On May 11, 2010 Diamond Aircraft Industry GmbH applied for an amendment to Type Certificate No. A47CE to include the new model DA- 40NG with the Austro Engine GmbH model E4 ADE. The model DA-40NG, which is a derivative of the model DA-40 currently approved under Type
Certificate No. A47CE, is a fully composite, four place, single-engine airplane with a cantilever low wing, T-tail airplane with the Austro
Engine GmbH model E4 diesel engine and an increased maximum takeoff gross weight from 1150 kilograms (kg) to 1280 kg (2535 pounds (lbs) to 2816 lbs).
DAI will use an EEC instead of a traditional mechanical control system on the model DA-40NG airplane. The EEC is certified as part of the engine design certification, and the certification requirements for engine control systems are driven by 14 CFR part 33 certification requirements. The guidance for the part 33 EEC certification requirement is contained in two advisory circulars: Advisory Circular
(AC) 33.28-1 and AC 33.28-2. The EEC certification, as part of the engine, addresses those aspects of the engine specifically addressed by part 33 and is not intended to address 14 CFR part 23 installation requirements. However, the guidance does highlight some of the aspects of installation that the engine applicant should consider during engine certification. The installation of an engine with an EEC system requires evaluation of environmental effects and possible effects on or by other airplane systems, including the part 23 installation aspects of the EEC functions. For example, the indirect effects of lightning, radio interference with other airplane electronic systems, and shared engine and airplane data and power sources.
The regulatory requirements in part 23 for evaluating the installation of complex electronic systems are contained in Sec. 23.1309. However, when Sec. 23.1309 was developed, the requirements of the rule were specifically excluded from applying to powerplant systems provided as part of the engine (reference Sec. 23.1309(f)(1)).
Although the parts of the system that are not certificated with the engine could be evaluated using the criteria of Sec. 23.1309, the analysis would not be useful and not be complete because it would not include the effects of the aircraft supplied power and data failures on the engine control system, and the resulting effects on engine power/ thrust. The integral nature of EEC installations require review of EEC functionality at the airplane level, as behavior acceptable for part 33 certification may not be acceptable for part 23 certification.
For over a decade, the Small Airplane Directorate has applied a special condition that required all EEC installations to comply with the requirements of Sec. 23.1309(a) through (e). The rationale for applying Sec. 23.1309 was that it was an existing rule that contained the best available requirements to apply to the installation of a complex electronic system; in this case, an EEC with aircraft interfaces. Additionally, special conditions for High Intensity
Radiated Fields (HIRF) were also applied prior to the codification of
Sec. 23.1308.
There are several difficulties for propulsion systems directly complying with the requirements of Sec. 23.1309. There are conflicts between the guidance material for Sec. 23.1309 and propulsion system capabilities and failure susceptibilities. The following figure is an excerpt from AC 23.1309-1D.
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Classification of failure
No safety effect
Minor
Major
Hazardous
Catastrophic conditions
--------------------------------------------------------------------------------------------------------------------
No probability
Allowable qualitative probability
requirement
Probable
Remote
Extremely remote
Extremely improbable
Effect on Airplane................. No effect on
Slight reduction in
Significant reduction Large reduction in
Normally with hull operational
functional
in functional
functional
loss. capabilities or
capabilities or
capabilities or
capabilities or safety.
safety margins.
safety margins.
safety margins.
Effect on Occupants................ Inconvenience for
Physical discomfort
Physical distress to Serious or fatal
Multiple fatalities. passengers.
for passengers.
passengers, possibly injury to an including injuries. occupant.
Effect on Flight Crew.............. No effect on flight
Slight increase in
Physical discomfort
Physical distress or Fatal injury or crew.
workload or use of
or a significant
excessive workload
incapacitation. emergency procedures. increase in workload. impairs ability to perform tasks.
Classes of
Allowable Quantitative Probabilities and Software (SW) and Complex Hardware (HW) DALs (Note 2). airplanes:
Class I............................ No Probability or SW &
