April 18, 2012

U.S. Department of Transportation 

Docket Operations, M–30 

West Building Ground Floor, Room W12–140

1200 New Jersey Avenue SE

Washington, DC 20590.

Re: Request for Extension of Comment Period: Docket No. FAA-2012-0187; Directorate Identifier 

2011-NM-094-AD; Airworthiness Directives; Boeing 757 Fuel Quantity indication Systems; 

Notice of Proposed Rulemaking; 77 Fed. Reg. 12506, March 1, 2012.

Dear Sir or Madam: 

Pursuant to 14 CFR §11.47, Airlines for America (A4A), on behalf of its member airlines1requests that the 

Administrator extend the time allowed for the submission of comments to the Notice of Proposed 

Rulemaking (proposal” or “NPRM”) cited in Docket Number FAA-2012-0187. The extension is requested 

in order to develop estimates of technical methods of compliance with the proposed airworthiness 

directive (AD) and estimates of the potential impacts of those methods.

If adopted, the proposal would require operators B-757 all-cargo airplanes to modify fuel quantity 

indication system (FQIS) wiring or fuel tank systems in accordance with a method approved by the 

Manager, Seattle Aircraft Certification Office (ACO), FAA. The general intent of this action is to prevent 

the development of an ignition source inside the center fuel tank. The proposal also states that FAA may 

publish similar proposals that would apply to other all-cargo airplane models. Comments to the proposal 

must be submitted to the Docket by April 30, 2012. 

Airlines for America is the principal trade and service organization of the U.S. scheduled airline industry. 

A4A members currently operate a fleet of 3,925 aircraft and possess in-depth, practical knowledge of fuel 

tank system maintenance and ignition prevention ADs. Our members account for 90 percent of the 

passenger and cargo traffic carried annually by U.S. scheduled airlines. The proposal would affect 133 

airplanes in the inventories of member fleets. Further, if FAA pursues similar proposals for other all-cargo 

airplane models, 63 percent of the all-cargo airplanes of A4A members would be affected. For these 

reasons, A4A has a unique interest in this rulemaking action.

 

1

A4A is the principal trade and service organization of the U.S. scheduled airline industry. A4A airline members are: 

Alaska Airlines, Inc.; American Airlines, Inc.; ASTAR Air Cargo, Inc.; Atlas Air, Inc.; Delta Air Lines, Inc.; Evergreen 

International Airlines, Inc.; Federal Express Corporation; Hawaiian Airlines; JetBlue Airways Corp.; Southwest Airlines 

Co.; United Continental Holdings, Inc.; UPS Airlines; and US Airways, Inc.

A4A associate airline members are: Air Canada
Docket No. FAA–2012–0187 

April 18, 2012 

P a g e 2

There are no service instructions available or under development that would provide a method of 

compliance with the proposed AD. Our liaison with Boeing indicates that compliance would require 

significantly greater modification of fuel tank systems than modifications mandated by earlier ADs for 

other airplane models, such as AD 99-09-04 and AD 98-20-40. Although those ADs accomplished the 

same design intent as the proposal, they were adopted before the effective date of Amendment 25-102 

(i.e., June 6, 2001). Our liaison indicates that applying the requirements of Amendment 25-102 to the 

design of the wiring of the B-757 FQIS would apply more demanding design standards, and they would 

to additional fuel tanks and more fuel tank components. Primarily for these reasons, the manufacturer

estimates that the proposed modification may exceed the impact of the Flammability Reduction Means 

(FRM) designed for the B-757, which most recently was quoted as $323,000 per airplane for parts alone. 

The proposal offers FRM as an alternative method of compliance, but in any case, the potential impact of 

the proposal portends to be an order of magnitude greater than the impact of the earlier, similar ADs. We 

are concerned that a credible assessment of impact may prove illusive, but that efforts should be made. 

Further, the proposal should be subject to a data-based risk analysis to assess whether a modification is 

necessary to meet the requirements of 14 CFR 25.981.

In order to better assess modifications that would comply with the proposal and their potential impacts, 

and to accomplish an updated risk analysis, A4A requests an extension of the comment period to June 

30, 2012. 

Please do not hesitate to call me to discuss this matter, or if you have any question. 

Sincerely, 

Joseph W. White 

Managing Director, Engineering & Maintenance

Airlines for America 

1301 Pennsylvania Avenue, NW, Suite 1100 

Washington, DC 20004 

202-626-4000

Cc: Ali Bahrami, FAA ANM–100

Tak Kobayashi, FAA ANM–140S