2010-7946. Airworthiness Directives; The Boeing Company Model 777-200, -200LR, -300, and -300ER Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Model 777-200, -200LR, -300, and -300ER series airplanes. This proposed AD would require removing and repairing the sealant at the four lower corners of the wing center section and the four lower t-chord segment gaps on each side of the wing center section. This proposed AD results from reports of fuel leakage from the center tank. We are proposing this AD to detect and correct improperly applied sealant, which could result in the disbonding and displacing of sealant, and consequent fuel leaks. On the ground, uncontained fuel leakage could result in pooling, and pooling combined with an ignition source could result in a fire.

DATES:

We must receive comments on this proposed AD by May 24, 2010.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Kevin Nguyen, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2010-0376; Directorate Identifier 2009-NM-267-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We have received reports that 7 operators have reported 9 cases of fuel leakage from the center tank on 9 airplanes. These airplanes had accumulated approximately 10 to 10,000 flight hours, 5 to 2,000 flight cycles, and 1 to 26 months in service. The leaks were found at the two aft lower corners of the wing center section and one leak was found at one of the four gaps between the lower t-chord segments on each side of the wing center section. The forward lower corners and the remaining gaps between the t-chord segments are also believed to be susceptible to fuel leakage. The leaks are believed to be the result of improperly applied sealant during production. This condition, if not detected and corrected, could result in failing by the disbonding and displacing of sealant, which can result in fuel leaks of up to 10 gallons per minute. During flight, the fuel would leak into areas that have been designed to accommodate fuel leakage, but on the ground, if the fuel leakage is not contained, it could result in pooling. This pooling combined with an ignition source could result in a fire.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 777-57-0063, Revision 1, dated May 14, 2009. The service bulletin describes procedures for removing and repairing the sealant at the four lower corners of the wing center section and the four lower t-chord segment gaps on each side of the wing center section.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 8 airplanes of U.S. registry. We also estimate that it would take about 10 work-hours per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $6,800, or $850 per product.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. “Subtitle VII: Aviation Programs,” describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in “Subtitle VII, Part A, Subpart III, Section 44701: General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866,

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and

3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

The Boeing Company: Docket No. FAA-2010-0376; Directorate Identifier 2009-NM-267-AD.

Comments Due Date

(a) We must receive comments by May 24, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 777-57-0063, Revision 1, dated May 14, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

(e) This AD results from reports of fuel leakage from the center tank. We are issuing this AD to detect and correct improperly applied sealant, which could result in the disbonding and displacing of sealant, and consequent fuel leaks. On the ground, uncontained fuel leakage could result in pooling, and pooling combined with an ignition source, could result in a fire.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Removal and Repair of Sealant

(g) Within 36 months or 6,000 flight cycles after the effective date of this AD, whichever occurs first: Remove and repair the sealant at the four lower corners of the wing center section and the four lower t-chord segment gaps on each side of the wing center section, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-57-0063, Revision 1, dated May 14, 2009.

Credit For Actions Accomplished According to Previous Issue of Service Bulletin

(h) Actions accomplished before the effective date of this AD in accordance with Boeing Special Attention Service Bulletin 777-57-0063, dated November 20, 2008, are considered acceptable for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Kevin Nguyen, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Information may be e-mailed to: [e-mail].

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Issued in Renton, Washington, on April 1, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.