Document ID: FAA-2011-0222-0005
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Dassault Aviation Airplanes; Withdrawal
Posted Date: 2012-06-20T04:00Z

[Federal Register Volume 77, Number 119 (Wednesday, June 20, 2012)]
[Proposed Rules]
[Pages 36950-36951]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-15097]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0222; Directorate Identifier 2010-NM-056-AD]
RIN 2120-AA64

Airworthiness Directives; Dassault Aviation Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Proposed rule; withdrawal.

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SUMMARY: The FAA withdraws a notice of proposed rulemaking (NPRM) that 
proposed a new airworthiness directive (AD) for certain Dassault 
Aviation Model FALCON 7X airplanes. The proposed AD would have required 
revising the maintenance program to incorporate a limitation that 
reduced time between overhauls, and required an initial overhaul, of 
the direct current (DC) generator (bearings). Since the proposed AD was 
issued, we have received new data that confirm the identified unsafe 
condition is not sufficient to warrant issuance of an AD. Accordingly, 
the proposed AD is withdrawn.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD action, the regulatory 
evaluation, any comments received, and other information. The address 
for the Docket Office (telephone 800-647-5527) is the Document 
Management Facility, U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 
227-1137; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Discussion

    We proposed to amend part 39 of the Federal Aviation Regulations 
(14 CFR part 39) with a notice of proposed rulemaking (NPRM) for a new 
AD for certain Dassault Aviation Model FALCON 7X airplanes. That NPRM 
was published in the Federal Register on March 15, 2011 (76 FR 13924). 
That

[[Page 36951]]

NPRM would have required revising the maintenance program to 
incorporate a limitation that reduced time between overhauls, and 
required an initial overhaul, of the DC generator (bearings). That NPRM 
resulted from mandatory continuing airworthiness information (MCAI) 
originated by an aviation authority of another country to identify and 
correct an unsafe condition on an aviation product. The MCAI described 
the unsafe condition as:

    Time between overhaul (TBO) of DC [direct current] generator 
bearings is set at 1,000 flight hours (FH) in the airworthiness 
limitations section of the Falcon 7X Aircraft Maintenance Manual 
Chapter 5.40.
    In service report has shown that the bearing current design 
cannot sustain the current TBO. * * *
* * * * *
    Failure to comply with those revised maintenance tasks could 
constitute an unsafe condition.

The proposed actions were intended to prevent failure of the DC 
generator bearings, which could lead to loss of the generator and 
potential loss of electrical power to the fly-by-wire system and 
subsequent loss of control of the airplane.

Actions Since NPRM (76 FR 13924, March 15, 2011) Was Issued

    Since we issued the NPRM (76 FR 13924, March 15, 2011), the 
airplane manufacturer provided further information on the redundancy of 
the electrical system that supplies power to the fly-by-wire system. 
There are three DC generators that can supply electrical power to the 
fly-by-wire system. Electrical power can also be supplied by two 
independent permanent magnet alternator converters that are dedicated 
to that system. Failure of all three DC generators to supply electrical 
power automatically triggers a command to deploy the ram air turbine, 
which will supply the airplane systems (including fly-by-wire) with 
sufficient electrical power for continued safe flight and landing.

FAA's Conclusions

    Upon further consideration, we have determined that, based on the 
airplane design, and the multiple electrical power generation sources, 
the potential loss of one DC generator due to an un-reduced maintenance 
interval would not result in loss of electrical power to the airplane. 
Therefore, the potential loss of one DC generator does not constitute 
an unsafe condition. Accordingly, the NPRM (76 FR 13924, March 15, 
2011) is withdrawn.
    Withdrawal of the NPRM (76 FR 13924, March 15, 2011) does not 
preclude the FAA from issuing another related action or commit the FAA 
to any course of action in the future.

Regulatory Impact

    Since this action only withdraws an NPRM (76 FR 13924, March 15, 
2011), it is neither a proposed nor a final rule and therefore is not 
covered under Executive Order 12866, the Regulatory Flexibility Act, or 
DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 
1979).

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Withdrawal

    Accordingly, we withdraw the NPRM, Docket No. FAA-2011-0222, 
Directorate Identifier 2010-NM-056-AD, which was published in the 
Federal Register on March 15, 2011 (76 FR 13924).

    Issued in Renton, Washington, on June 12, 2012.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-15097 Filed 6-19-12; 8:45 am]
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