2012-14252. Airworthiness Directives; The Boeing Company

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 777 airplanes. This proposed AD was prompted by reports of failure of wire support clamps in the forward section of the aft pressure bulkhead. This proposed AD would require a detailed inspection of the clamps on the power feeder cable auxiliary power unit (APU) to determine if certain clamps are installed, and related investigative and corrective actions if necessary. We are proposing this AD to prevent failure of the clamp, which could result in wire chafing and potential arcing and consequent fire in section 48 (a flammable fluid leakage zone) or heat damage to the APU power feeder cable, insulation blankets, or pressure bulkhead.

DATES:

We must receive comments on this proposed AD by July 27, 2012.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, 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]; 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:

Georgios Roussos, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax: [phone]; email: [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-2012-0595; Directorate Identifier 2012-NM-055-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 of failure of wire support clamps in the forward section of the aft pressure bulkhead. This condition, if not corrected, could result in wire chafing and potential arcing and consequent fire in section 48 (a flammable fluid leakage zone) or heat damage to the APU power feeder cable, insulation blankets, or pressure bulkhead.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011. The service information describes procedures for a detailed inspection of the clamps on the APU power feeder cable to determine if certain clamps are installed, and related investigative and corrective actions if necessary.

The related investigative actions include a general visual inspection for damage of the APU power feeder cable and heat damage of the insulation blanket adjacent to the clamp, a detailed inspection for primer discoloration and structural deterioration of the fuselage structure, and an eddy current inspection for heat damage of the aluminum structure.

The corrective actions include replacing the affected clamps, repairing the APU power feeder cable, the installation blanket, and the aluminum structure.

Clarification of Requirements

Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011, does not include a step for the corrective action if no damage is found during the detailed inspection for primer discoloration and structural deterioration of the section 47 and 48 fuselage structure. For the corrective action, this AD requires repairing the APU power feeder cable and insulation blanket and replacing the existing non-TA027063 clamps with TA027063 clamps, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011.

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 “Differences Between the Proposed AD and the Service Information.”

Differences Between the Proposed AD and the Service Information

The service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• In accordance with a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings.

Costs of Compliance

We estimate that this proposed AD affects 164 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
Inspection and Clamp Replacement	8 work-hours × $85 per hour = $680	$500	$1,180	$193,520

We estimate the following costs to do any necessary repair 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 this repair:

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Inspection and Repair of the Pressure Bulkhead	48 work-hours × $85 per hour = $4,080	$0	$4,080

We have received no definitive data that would enable us to provide parts cost estimates for the on-condition repairs specified in this proposed AD.

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-2012-0595; Directorate Identifier 2012-NM-055-AD.

(a) Comments Due Date

We must receive comments by July 27, 2012.

(b) Affected ADs

None.

(c) Applicability

This AD applies to The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 2421; AC Generator/Alternator.

(e) Unsafe Condition

This AD was prompted by reports of failure of wire support clamps in the forward section of the aft pressure bulkhead. We are issuing this AD to prevent failure of the clamp, which could result in wire chafing and potential arcing and consequent fire in section 48 (a flammable fluid leakage zone) or heat damage to the auxiliary power unit (APU) power feeder cable, insulation blankets, or pressure bulkhead.

(f) Compliance

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

(g) Detailed Inspection of the Clamps

Within 48 months after the effective date of this AD: Do a detailed inspection of the clamps on the APU power feeder cable to determine if TA027063 clamps are installed, and all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011, except as required by paragraph (h) and (i) of this AD. Do all related investigative and corrective actions before further flight.

(h) Exception to the Service Bulletin

If during any inspection of the fuselage structure required by paragraph (g) of this AD, no primer discoloration or structural deterioration is found, before further flight, repair the APU power feeder cable and insulation blanket and replace the existing clamps, in accordance with steps 3.B.7, 3.B.8, and 3.B.9 of the Accomplishment Instructions of Boeing Alert Service Bulletin 777-24A0119, dated November 11, 2011.

(i) Repair Approval

Where the service bulletin specifies to do the repair in accordance to the instruction from Boeing, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

(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 emailed 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 structural 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 structural repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(k) Related Information

(1) For more information about this AD, contact Georgios Roussos, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax: [phone]; email: [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]; 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.

Issued in Renton, Washington, on May 31, 2012.

Michael Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.