2010-19832. Airworthiness Directives; The Boeing Company Model 767-300 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 767-300 series airplanes. This proposed AD would require repetitive inspections for cracks in the fuselage skin and backup structure at the lower very high frequency (VHF) antenna cutout at station 1197 + 99 between stringers 39L and 39R, and corrective actions if necessary. Certain repairs would terminate certain inspection requirements. This proposed AD results from reports of cracking found in the section 46 fuselage lower skin around the periphery of the VHF antenna baseplate at station 1197 + 99. We are proposing this AD to detect and correct fatigue cracks in the fuselage skin and internal backup structure, which could result in rapid decompression of the airplane.

DATES:

We must receive comments on this proposed AD by September 27, 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:

Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, 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-2010-0796; Directorate Identifier 2010-NM-007-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 been advised that two operators reported cracks found in the section 46 fuselage lower skin around the periphery of the VHF antenna baseplate at station 1197 + 99. One operator reported 5 cracks, with a maximum length of 11 inches, found on an airplane that had accumulated 38,804 total flight hours and 34,929 total flight cycles. Another operator reported a maximum crack length of 9.5 inches found on an airplane that had accumulated 60,467 total flight hours and 29,185 total flight cycles. Boeing investigation has revealed that the fuselage skin and internal backup structural cracks are attributed to fatigue. This fatigue is the result of bending loads in the skin caused by vibration of the antenna in flight. No operator reported crack findings for the backup structure. Fatigue cracks in the fuselage skin and internal backup structure, if not corrected, could result in rapid decompression of the airplane.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 767-53-0207, dated December 17, 2009. The service bulletin describes procedures for repetitive inspections for cracks in the fuselage skin and backup structure at the lower VHF antenna cutout at station 1197 + 99, between stringers 39L and 39R. The inspections include an external detailed inspection of the fuselage skin at the lower aft VHF antenna cutout, and an internal detailed inspection of the backup structure.

Corrective actions include repairing fuselage skin cracks, which would eliminate the need to repeat the external detailed inspection; and repairing or replacing cracked backup structure parts.

In the service bulletin, the compliance time for the external detailed inspection is before the accumulation of 25,000 total flight cycles, or within 3,000 flight cycles after the date on the service bulletin, whichever occurs later. The compliance time for the internal detailed inspection is before the accumulation of 25,000 total flight cycles, or within 3,000 flight cycles after the date on the service bulletin, whichever occurs later; or the inspection may be deferred for an additional 6,000 flight cycles if no fuselage skin cracks are found during the external detailed inspection.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined that 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 93 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per product	Number of U.S.-registered airplanes	Fleet cost
Inspections	3	$85	$255	93	$23,715

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-2010-0796; Directorate Identifier 2010-NM-007-AD.

Comments Due Date

(a) We must receive comments by September 27, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 767-300 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 767-53-0207, dated December 17, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from reports of cracking found in the section 46 fuselage lower skin around the periphery of the very high frequency (VHF) antenna baseplate at station 1197 + 99. The Federal Aviation Administration is issuing this AD to detect and correct fatigue cracks in the fuselage skin and internal backup structure, which could result in rapid decompression of the airplane.

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.

Inspections

(g) Inspect for cracks in the fuselage skin and backup structure at the lower VHF antenna cutout at station 1197 + 99, between stringers 39L and 39R, by doing an external detailed inspection, with the antenna removed, of the fuselage structure at the lower aft VHF antenna cutout, and an internal detailed inspection of the backup structure. Do the inspections in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 767-53-0207, dated December 17, 2009 (“the service bulletin”). Do the inspections at the applicable time specified in paragraph 1.E., “Compliance,” of the service bulletin, except, where the service bulletin specifies a compliance after the date on the service bulletin, this AD requires compliance within the specified time after the effective date of this AD.

(1) If no crack is found, repeat the external detailed inspection, without removing the antenna, at intervals not to exceed 3,000 flight cycles.

(2) If any crack is found in the fuselage, repair before further flight, in accordance with the service bulletin. Accomplishment of this repair terminates the repetitive external detailed inspections of the fuselage skin required by this AD.

(3) If any crack is found in the backup structure, before further flight, repair or replace the cracked part(s), in accordance with the service bulletin.

Alternative Methods of Compliance (AMOCs)

(h)(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: Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, 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 refer to this AD.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on August 4, 2010.

Stephen P. Boyd,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.