[Federal Register Volume 70, Number 224 (Tuesday, November 22, 2005)]
[Notices]
[Page 70653]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23100]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Proposed Advisory Circular 25.981-2A, Fuel Tank Flammability

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of available of proposed Advisory Circular (AC) 25.981-
2A, and request for comments.

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SUMMARY: This notice announces the availability of and requests 
comments on a proposed advisory circular (AC) which sets forth an 
acceptable means, but not the only means, of demonstration compliance 
with the provisions of the airworthiness standards for transport 
category airplanes related to Fuel Tank Flammability Reduction. This 
proposed AC complements revisions to the airworthiness standards that 
are being proposed by a separate notice. This notice is necessary to 
give all interested persons an opportunity to present their views on 
the proposed AC.

DATES: Comments must be received on or before March 20, 2006.

ADDRESSES: Send all comments on proposed AC to: Federal Aviation 
Administration, Attention: Mike Dostert, Propulsion/Mechanical Systems 
Branch, ANM-112, FAA, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, WA 98055-4056. 
Comments may be inspected at the above address between 7:30 a.m. and 4 
p.m. weekdays, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Jan Thor, Transport Standards Staff, 
at the address above, telephone (425) 227-2127.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to comment on the proposed AC by 
submitting such written data, views, or arguments, as they may desire. 
Commenters should identify AC 25.981-2A and submit comments, in 
duplicate, to the address specified above. All communications received 
on or before the closing date for comments will be considered by the 
Transport Standards Staff before issuing the final AC. The proposed AC 
can be found and downloaded from the Internet at http://www.airweb.faa.gov/rgl under ``Draft Advisory Circulars.'' A paper copy 
of the proposed AC may be obtained by contacting the person named above 
under the caption FOR FURTHER INFORMATION CONTACT.

Discussion

    This proposed AC provides information and guidance on compliance 
with the airworthiness standards for transport category airplanes about 
limiting the time a fuel tank may be flammable or mitigation of hazards 
from flammable fuel air mixtures within fuel tanks. This guidance is 
applicable to transport category airplanes for which a new, amended, or 
supplemental type certificate is requested and affected existing design 
approval holders as stated in proposed Sec. Sec.  25.1815, 25.1817, 
25.1819, and 25.1821 contained in a proposed new subpart I to Title 14, 
Code of Federal Regulations (14 CFR) part 25, ``Continued Airworthiness 
and Safety Improvement.'' The AC also provides guidance on compliance 
with the associated proposed requirements for operators of affected 
airplanes that must comply with the requirements of 14 CFR parts 91, 
121, 125, and 129 (for a foreign person or foreign air carrier 
operating a U.S.-registered airplane) to incorporate flammability 
mitigation means by specified dates.
    The Notice of Proposed Rulemaking would not apply the proposed new 
requirements to transport category airplanes designed solely for cargo 
carriage. However, AC 25.981-2 remains applicable to these airplanes, 
which must comply with the current flammability standards contained in 
Sec.  25.981(c) that would be moved to the proposed section Sec.  
25.981(e). We will consider combining this guidance for all transport 
category airplanes into one AC when the final rule and AC are issued.
    It is one means, but not the only means, of complying with the part 
25 revisions proposed in Notice No. 05-14 entitled ``Fuel Tank 
Flammability Reduction,'' published in this same edition of the Federal 
Register. Issuance of AC 25.981-2A is contingent on final adoption of 
the proposed revisions to part 25.

    Issued in Renton, Washington, on November 16, 2005.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-23100 Filed 11-21-05; 8:45 am]
BILLING CODE 4910-13-M