2011-27652. Airworthiness Directives; The Boeing Company 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 The Boeing Company Model 757 airplanes. This proposed AD would require inspecting for discrepancies and insufficient coverage of the secondary fuel barrier, determining the thickness of the secondary fuel barrier, and corrective actions if necessary. This proposed AD was prompted by reports that inspections of the wing center section revealed defective, misapplied, or missing secondary fuel vapor barrier on the center fuel tank. We are proposing this AD to detect and correct defective surfaces and insufficient thickness of secondary fuel barrier, which could allow fuel leaks or fumes into the pressurized cabin, and allow fuel or fuel vapors to come in contact with an ignition source, which could result in a fire or an explosion.

DATES:

We must receive comments on this proposed AD by December 12, 2011.

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: Deliver to Mail address above 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 (phone: [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; phone: [phone]; fax: [phone]; e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2011-1094; Directorate Identifier 2011-NM-070-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 received reports that inspections of the wing center section revealed defective, misapplied, or missing secondary fuel vapor barrier on the center fuel tank. The secondary fuel barrier is applied external to the fuel tank walls, which are subject to cabin pressure to provide a secondary means to contain fuel and fuel vapors. When the secondary fuel barrier is applied satisfactorily, it protects the pressurized cabin areas from fuel leaks and fumes. If the secondary fuel barrier is defective, fuel or fumes can leak through fastener holes or cracks in the structure and pass into the passenger compartment. There have been no reports from operators of fuel leaks or fumes in the passenger compartment. We are proposing this AD to detect and correct defective surfaces and insufficient thickness of secondary fuel barrier, which could allow fuel leaks or fumes into the pressurized cabin, and allow fuel or fuel vapors to come in contact with an ignition source, which could result in a fire or an explosion.

Related Rulemaking

On June 10, 2005, the FAA issued AD 2005-13-15, Amendment 39-14152 (70 FR 36486, June 24, 2005), applicable to certain Boeing Model 737-200, -200C, -300, -400, -500, -600, -700, -700C, -800, and -900 series airplanes, which requires a one-time detailed inspection for discrepancies of the secondary fuel vapor barrier of the wing center section, and related investigative and corrective actions if necessary. That AD was prompted by reports that the secondary fuel vapor barrier was not applied correctly to, or was missing from, certain areas of the wing center section. The actions required by that AD are intended to prevent fuel or fuel vapors from leaking into the cargo or passenger compartments and coming into contact with a possible ignition source, which could result in fire or explosion.

Relevant Service Information

We reviewed Boeing Service Bulletins 757-57-0060, Revision 2, dated May 24, 2007 (for Model 757-200, 757-200PF, and 757-200CB series airplanes); and 757-57-0061, Revision 1, dated May 24, 2007 (for Model 757-300 series airplanes). These service bulletins describe procedures for, depending on airplane configuration, inspecting for discrepancies and insufficient coverage of the secondary fuel barrier, determining the thickness of the secondary fuel barrier, and corrective actions if necessary. Discrepancies include missing, peeled, non-continuous, or non-transparent secondary fuel barrier; small air bubbles, air pockets, blister-like areas, or solid particles in the secondary fuel barrier; fillet sealant, primer, corrosion-inhibiting compound or other finishes applied to the top of the secondary fuel barrier; missing fillet (cap) seals; or areas of secondary fuel barrier whose thickness is less than or greater than specified limits; or areas not having a transparent quality that makes it possible to see a crack in the structure; or areas not having a minimum application coverage area. Corrective actions include repairing the secondary fuel barrier, including removal and reapplication, if needed; or applying more secondary fuel barrier, as needed.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Information.”

Differences Between the Proposed AD and the Service Information

Although Boeing Service Bulletin 757-57-0060, Revision 2, and Boeing Service Bulletin 757-57-0061, Revision 1, both dated May 24, 2007, specify to send the inspection results to the manufacturer, this proposed AD would not require any report. Boeing Service Bulletin 757-57-0060, Revision 2, and Boeing Service Bulletin 757-57-0061, Revision 1, both dated May 24, 2007, refer to a “detailed visual inspection” for discrepancies and insufficient coverage of the secondary fuel barrier. We have determined that the procedures in the service bulletin should be described as a “detailed inspection.” Note 1 has been included in this AD to define this type of inspection.

Costs of Compliance

We estimate that this proposed AD affects 619 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Access and inspect secondary fuel barrier	42 work-hours × $85 per hour = $3,570 per inspection	$0	$3,570	$2,209,830

We estimate the following costs to do any necessary repairs that would be required based on the results of the proposed inspection. We have no way of determining the number of aircraft that might need these repairs:

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Apply secondary fuel barrier	7 work-hours × $85 per hour = $595 per secondary fuel barrier application	$0	$595

According to the manufacturer, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.

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),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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.

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 airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2011-1094; Directorate Identifier 2011-NM-070-AD.

Comments Due Date

(a) We must receive comments by December 12, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 757-200, 757-200PF, and 757-200CB series airplanes, certificated in any category, as identified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; and Model 757-300 series airplanes, certificated in any category, as identified in Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007.

Subject

(d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

(e) This proposed AD was prompted by reports that inspections of the wing center section revealed defective, misapplied, or missing secondary fuel vapor barrier on the center fuel tank. We are issuing this AD to detect and correct defective surfaces and insufficient thickness of secondary fuel barrier, which could allow fuel leaks or fumes into the pressurized cabin, and allow fuel or fuel vapors to come in contact with an ignition source, which could result in a fire or an explosion.

Compliance

(f) Comply with this AD within the compliance times specified, unless already done.

Detailed Inspection

(g) For airplanes identified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007, as Group 1, Group 2, and Group 4 Configuration 1; and airplanes identified in Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007, as Group 1, Group 2, and Group 3 Configuration 1: Within 60 months after the effective date of this AD, do a detailed inspection to detect discrepancies of the secondary fuel barrier at the front spar and the upper panel of the wing center section, and if discrepancies exist, repair before further flight, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate access procedures may be required.”

Inspection of Minimum Application Coverage Area

(h) For Group 3 airplanes identified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; and Group 2 airplanes identified in Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007: Within 60 months after the effective date of this AD, do a detailed inspection of the front spar and the upper panel to ensure the secondary fuel barrier application covers the minimum area specified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable. If the secondary fuel barrier does not cover the minimum specified area, apply more secondary fuel barrier before further flight, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable.

Measurement of Thickness of Secondary Fuel Barrier

(i) For Group 1, Group 2, and Group 4 Configuration 1 airplanes identified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; and for Group 1, Group 2, and Group 3 Configuration 1 airplanes identified in Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007: Within 60 months after the effective date of this AD, measure the thickness of the secondary fuel barrier. If the thickness is less than or over the acceptable limits defined in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable, apply more secondary fuel barrier or repair before further flight, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable.

(j) For Group 4, Configuration 2 airplanes identified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; and Group 3, Configuration 2 airplanes identified in Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007: Within 60 months, review the maintenance records to determine if there was a minimum of 0.005 inch of new secondary fuel barrier applied, or if the thickness of the secondary fuel barrier cannot be determined from the maintenance records, measure the thickness of the secondary fuel barrier. If the thickness is less than or over the acceptable limits specified in Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable, apply more secondary fuel barrier or repair before further flight, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; or Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; as applicable.

No Reporting Requirement

(k) Although Boeing Service Bulletin 757-57-0060, Revision 2, dated May 24, 2007; and Boeing Service Bulletin 757-57-0061, Revision 1, dated May 24, 2007; specify to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be e-mailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

Related Information

(m)(1) For more information about this AD, contact Kevin Nguyen, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: [phone]; fax: [phone]; e-mail: [e-mail].

(2) For service information identified in this 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.boeingfleet.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.

* * * * *

Issued in Renton, Washington, on October 17, 2011.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.