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 repetitive detailed inspections for disbonding and tearing and measurements for wear of the internal diameter (ID) of the Karon-lined bushings of the bulkhead support jackscrew fitting and of the jackscrew fitting of the horizontal stabilizer; repetitive installations of the horizontal stabilizer trim actuator (HSTA); and if necessary, replacement of the bushings with new bushings and all applicable related investigative and corrective actions. This proposed AD results from a report indicating that a Karon-lined bushing with the liner broken into five pieces was found during a scheduled inspection of the HSTA components; the broken liner had worn and disbonded from the bushing. We are proposing this AD to detect and correct discrepancies of the HSTA attachment locations, which could result in reduced structural integrity of the horizontal stabilizer and consequent loss of controllability of the airplane.

DATES:

We must receive comments on this proposed AD by January 18, 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: 202-493-2251.
• 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 206-544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com; 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 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Duong Tran, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6452; fax (425) 917-6590.

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-2010-1156; Directorate Identifier 2010-NM-128-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 a report indicating that a Karon-lined bushing with the liner broken into five pieces was found during a scheduled inspection of the horizontal stabilizer trim actuator (HSTA) components; the broken liner had worn and disbonded from the bushing. The broken liner was found on a 777-200 airplane that had accumulated 35,145 total flight hours and 5,335 total flight cycles. Analysis by the manufacturer revealed that the broken liner was one of 149 bushings on which an early manufacturing process was used; that process has since been improved. Further investigation and analysis by the manufacturer shows that Karon-lined bushings in the HSTA and HSTA attachment locations on the airplane structure using both the early and the improved process are susceptible to wear in service. The analysis also shows that the wear may cause excessive joint clearance which could lead to fatigue cracking of the pins. This condition, if not corrected, could result in reduced structural integrity of the horizontal stabilizer and consequent loss of controllability of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 777-55A0017, dated May 20, 2010, which describes procedures for:

• Repetitive detailed inspections for disbonding and tearing and measurements for wear of the internal diameter (ID) of the Karon-lined bushings of the bulkhead support jackscrew fitting; and replacement of the bushings with new bushings if necessary: The replacement includes related investigative and corrective actions, if necessary. The related investigative actions include a surface high-frequency eddy current inspection for cracking of the inner surface of the hole, and measurement of the ID, of the intermediate sleeve. The corrective action for cracking of the intermediate sleeve or measurements outside the ID specified in the service bulletin is replacement of the intermediate sleeve, including related investigative and corrective actions if necessary. The related investigative actions include a surface high-frequency eddy current inspection for cracking of the inner surface of the hole, and measurement of the ID of the hole of the bulkhead support jackscrew fitting. The corrective action for cracking of the bulkhead support jackscrew fitting or measurements outside the ID specified in the service bulletin is contacting Boeing.
• Repetitive detailed inspections for disbonding and tearing and measurements for wear of the internal diameter (ID) of the Karon-lined bushings of the jackscrew fitting of the horizontal stabilizer; and replacement of the bushings with new bushings if necessary.
• Repetitively installing either a known serviceable or overhauled HSTA.

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, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between the Proposed AD and 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:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Organization Designation Authorization whom we have authorized to make those findings.

Costs of Compliance

We estimate that this proposed AD would affect 145 airplanes of U.S. registry. We also estimate that it would take about 7 work-hours per product to comply with the detailed inspection, measurement, and installation in 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 $86,275, or $595 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.