2011-24748. 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 767-200 and -300 series airplanes. This proposed AD would require repetitive inspections for cracking of the aft pressure bulkhead at station (STA) 1582, repair or replacement of any cracked bulkhead, and eventual replacement of the aft pressure bulkhead at STA 1582 with a new bulkhead. Accomplishing the replacement would terminate the repetitive inspections specified in this proposed AD. This proposed AD was prompted by reports of multiple site damage cracks in the radial web lap and tear strap splices of the aft pressure bulkhead at STA 1582 due to fatigue. We are proposing this AD to prevent fatigue cracking of the aft pressure bulkhead, which could result in rapid decompression of the airplane and possible damage or interference with the airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane.

DATES:

We must receive comments on this proposed AD by November 14, 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, WA 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:

Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 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-2011-0993; Directorate Identifier 2011-NM-018-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 of multiple site damage (MSD) cracks in the radial web lap and tear strap splices of the aft pressure bulkhead at station (STA) 1582 due to fatigue. This cracking was found on multiple airplanes with 31,746 to 36,597 total flight cycles. On four airplanes, the crack findings revealed MSD fatigue cracking common to the radial web lap splices. Design changes to improve the durability of the bulkhead were made in production. This condition, if not corrected, could result in rapid decompression of the airplane and possible damage or interference with the airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane.

Other Relevant Rulemaking

On February 25, 2004, we issued AD 2004-05-16, Amendment 39-13511 (69 FR 10917, March 9, 2004), for certain Model 767-200 and -300 series airplanes. That AD requires repetitive inspections of the aft pressure bulkhead web, and corrective action if necessary.

On January 31, 2005, we issued AD 2005-03-11, Amendment 39-13967 (70 FR 7174, February 11, 2005), corrected on February 28, 2005 (70 FR 12119, March 11, 2005), for certain Model 767 airplanes. That AD requires repetitive detailed and eddy current inspections of the aft pressure bulkhead for damage and cracking, and repair if necessary. That AD also requires one-time detailed and high frequency eddy current inspections of any “oil-can” located on the aft pressure bulkhead, and related corrective actions if necessary.

Since issuance of AD 2004-05-16, Amendment 39-13511 (69 FR 10917, March 9, 2004); and AD 2005-03-11, Amendment 39-13967 (70 FR 12119, March 11, 2005); the manufacturer has developed design changes that improve the durability of the bulkhead; therefore, we have determined that further rulemaking is necessary, and this proposed AD follows from that determination. Accomplishing the inspections required by this AD terminates the repetitive inspections required by paragraph (b) of AD 2004-05-16, and paragraph (f) of AD 2005-03-11.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009. The service information describes procedures for repetitive detailed, low- and mid-frequency eddy current inspections of the aft pressure bulkhead at STA 1582 for cracks and replacement or repair of any cracked bulkhead found. The service information also describes procedures for eventual replacement of the aft pressure bulkhead at STA 1582 with a new bulkhead, which eliminates the need for the repetitive inspections.

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 the same type design.

Proposed AD Requirements

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

Difference Between the Proposed AD Service Information

Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009, recommends accomplishing the inspections within 1,600 flight cycles after the most recent inspection done in accordance with Boeing Alert Service Bulletin 767-53A0026, Revision 5, dated January 29, 2004; however, it does not include a grace period for airplanes that might have exceeded that number of flight cycles since accomplishing the most recent inspection, or for airplanes on which the inspections have not been initiated. This proposed AD includes a grace period of 1,600 flight cycles for all airplanes.

Clarification of Certain Requirements

Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009, specifies replacing the bulkhead at STA 1582 with a new bulkhead if any crack is found during any inspection; however, paragraph 3.B.2., of the Accomplishment Instructions specifies repairing or replacing the bulkhead at STA 1582 if any crack is found. This proposed AD requires either replacing or repairing any cracked bulkhead and doing the repetitive inspections if the crack is repaired, until the replacement required by paragraph (h) of this proposed AD is done.

Costs of Compliance

We estimate that this proposed AD affects 83 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
Inspections	22 work-hours × $85 per hour = $1,870 per inspection cycle	0	$1,870	$155,210
Replacement	1,541 work-hours × $85 per hour = $130,985	$399,539	530,524	44,033,492

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-2011-0993; Directorate Identifier 2011-NM-018-AD.

Comments Due Date

(a) We must receive comments by November 14, 2011.

Affected ADs

(b) Certain requirements of this AD affect certain requirements of AD 2004-05-16, Amendment 39-13511 (69 FR 10917, March 9, 2004); and AD 2005-03-11, Amendment 39-13967 (70 FR 7174, February 11, 2005), corrected on February 28, 2005 (70 FR 12119, March 11, 2005).

Applicability

(c) This AD applies to The Boeing Company Model 767-200 and -300 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009.

Subject

(d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD was prompted by reports of multiple site damage cracks in the radial web lap and tear strap splices of the aft pressure bulkhead at station (STA) 1582 due to fatigue. We are issuing this AD to prevent fatigue cracking of the aft pressure bulkhead, which could result in rapid decompression of the airplane and possible damage or interference with the airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane.

Compliance

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

Repetitive Inspections

(g) Except as provided by paragraph (h) of this AD: Before the accumulation of 43,000 total flight cycles, or within 1,600 flight cycles after the effective date of this AD, whichever occurs later, do detailed, low-frequency eddy current, and mid-frequency eddy current inspections for cracking of the aft pressure bulkhead at STA 1582, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009. If any crack is found, before further flight, replace the bulkhead as required by paragraph (h) of this AD, or repair the crack in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009, and repeat the inspections thereafter at intervals not to exceed 1,600 flight cycles. If no crack is found, repeat the inspections thereafter at intervals not to exceed 1,600 flight cycles. Accomplishing the inspections required by this paragraph terminates the repetitive inspections required by paragraph (b) of AD 2004-05-16, Amendment 39-13511 (69 FR 10917, March 9, 2004); and paragraph (f) of AD 2005-03-11, Amendment 39-13967 (70 FR 7174, February 11, 2005), corrected on February 28, 2005 (70 FR 12119, March 11, 2005).

Replacement

(h) Except as provided by paragraph (g) of this AD: Before the accumulation of 43,000 total flight cycles, or within 5,000 flight cycles after the effective date of this AD, whichever occurs later: Replace the aft pressure bulkhead at STA 1582 with a new bulkhead, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0139, dated November 12, 2009. Accomplishing the replacement in this paragraph terminates the repetitive inspections required by paragraph (g) of 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. 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.

(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.

Related Information

(j) For more information about this AD, contact Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone [phone]; fax [phone]; e-mail: [e-mail].

(k) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, WA 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 98057-3356. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on September 7, 2011.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.