April 18 , 2012

U.S. Department of Tra nsportation 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 Identif ier 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 ), o n behalf of its me mber airlines 1 reque s ts 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 estimate s of the potential i mpact s of those methods

. If adopted, the proposal would require operators B

- 757 al l

- cargo airplanes to modify fuel quantity indication system (FQIS) wiring or fuel tank systems i n 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. T he proposal also states that F A A may publish similar proposals that would apply to other all

- cargo airplane models. C omments to the proposal must be submitted t o the Docket by April 30, 2012

.
Airlines for America is the principal trade and service organi zation of the U.S. scheduled airlin e industry. A4A members currently operate a fleet of 3,925 aircraft and possess in

- depth, practical knowledge of fuel t ank system maintenance and ignition prevention ADs. O ur members account for 90 percent of the passen ger 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 model s, 63 percent of the all

- cargo airplanes of A 4 A 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 CanadaDocket No. FAA

– 2012

– 0187

April 1 8 , 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 t hose 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 fue l tanks and more fuel tank components. Primarily for these reasons, the manufacturer estimat es 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 proposa l 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 ma y 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 th at would comply with the proposal and their potential impact s , 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 quest ion.
Sincerely,

Joseph W. White
Managing Director, Engineering & Maintenance Airlines for America 1301 Pennsylvania Avenue, NW, Suite 1100 Washington, DC 20004 202

- 626

- 4000

C c: Ali Bahrami, FAA ANM

– 1 00 Tak Kobayashi, FAA ANM

– 140S