E6-17428. Airworthiness Directives; Boeing Model 777-200 Series Airplanes Equipped with General Electric GE90-94B Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 777-200 series airplanes equipped with General Electric GE90-94B engines. This AD requires inspecting to determine the part number of the identification plate of the torque box on the thrust reversers (TRs), and investigative and corrective actions if necessary. This AD results from engine certification testing which revealed that TRs on GE90-94B engines have inner walls that could develop disbonding in the upper bifurcation radii. Disbonding was found in an equivalent inner wall used during the testing. We are issuing this AD to prevent failure of a TR and adjacent components and their consequent separation from the airplane during flight or during a refused takeoff (RTO). These separated components could cause structural damage to the airplane or damage to other airplanes and possible injury to people on the ground. TR failure during a RTO could also cause the engine to produce forward thrust, resulting in asymmetric thrust and possible runway excursion.

DATES:

This AD becomes effective November 3, 2006.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of November 3, 2006.

We must receive comments on this AD by December 18, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Gary Oltman, Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

We have received a report indicating that engine certification testing on certain Boeing Model 777-200 series airplanes with General Electric GE90 engines revealed that certain thrust reversers (TRs) have inner walls that could develop disbonding in the upper bifurcation radii. Disbonding and structural degradation was found in an equivalent inner wall used during the testing. Investigation revealed that the disbonding was caused by a flight maneuver that applied too much stress in the upper bifurcation radii composite materials. This condition, if not corrected, could result in failure of a TR and adjacent components and their consequent separation from the airplane during flight or during a refused takeoff (RTO). These separated components could cause structural damage to the airplane or damage to other airplanes and possible injury to people on the ground. TR failure during a RTO could also cause the engine to produce forward thrust, resulting in asymmetric thrust and possible runway excursion.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 777-78A0056, dated April 20, 2006. The service bulletin describes procedures for a general visual inspection to determine the part number on the identification plate of the torque box on the TRs, and investigative and corrective actions if necessary. If the identification plate shows any part number specified in paragraph 3.B.1.a. of the service bulletin, without the service bulletin number as a modification number, the investigative and corrective actions include, among other things, replacing the existing TRs with new or serviceable TRs, and marking the service bulletin number on the identification plate of the torque box. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

The Boeing service bulletin refers to Spirit AeroSystems Document MAA7-70023-1, dated November 22, 2005, as an additional source of service information for accomplishing the corrective actions.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design that may be registered in the U.S. at some time in the future. Therefore, we are issuing this AD to prevent failure of a TR and adjacent components and their consequent separation from the airplane during flight or during a RTO. These separated components could cause structural damage to the airplane or damage to other airplanes and possible injury to people on the ground. TR failure during a RTO could also cause the engine to produce forward thrust, resulting in asymmetric thrust and possible runway excursion. This AD requires accomplishing the actions specified in the Boeing service information described previously, except as discussed under “Difference Between the AD and the Service Information.”

Difference Between the AD and the Service Information

You should note that, although Boeing Alert Service Bulletin 777-78A0056 specifies that you may contact the manufacturer for repair instructions, this AD requires you to repair in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane that have been approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the FAA to make those findings.

Costs of Compliance

None of the airplanes affected by this action are on the U.S. Register. All airplanes affected by this AD are currently operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, we consider this AD necessary to ensure that the unsafe condition is addressed if any affected airplane is imported and placed on the U.S. Register in the future.

If an affected airplane is imported and placed on the U.S. Register in the future, the required inspection would take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD would be $80 per airplane.

FAA's Determination of the Effective Date

No airplane affected by this AD is currently on the U.S. Register. Therefore, providing notice and opportunity for public comment is unnecessary before this AD is issued, and this AD may be made effective in less than 30 days after it is published in the Federal Register.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2006-26085; Directorate Identifier 2006-NM-142-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

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 have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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 that the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2006-21-09 Boeing: Amendment 39-14794. Docket No. FAA-2006-26085; Directorate Identifier 2006-NM-142-AD.

Effective Date

(a) This AD becomes effective November 3, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 777-200 series airplanes equipped with General Electric GE90-94B engines; certificated in any category; as identified in Boeing Alert Service Bulletin 777-78A0056, dated April 20, 2006.

Unsafe Condition

(d) This AD results from engine certification testing which revealed that thrust reversers (TRs) on GE90-94B engines have inner walls that could develop disbonding in the upper bifurcation radii. Disbonding was found in an equivalent inner wall used during the testing. We are issuing this AD to prevent failure of a TR and adjacent components and their consequent separation from the airplane during flight or during a refused takeoff (RTO). These separated components could cause structural damage to the airplane or damage to other airplanes and possible injury to people on the ground. TR failure during a RTO could also cause the engine to produce forward thrust, resulting in asymmetric thrust and possible runway excursion.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

General Visual Inspection/Investigative and Corrective Actions

(f) Within 24 months after the effective date of this AD: Do a general visual inspection to determine the part number of the identification plate of the torque box on the TRs, and do all applicable investigative and corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-78A0056, dated April 20, 2006. If any discrepancy is found and the service bulletin specifies to contact Boeing for appropriate action: Before further flight, repair the TR using a method approved in accordance with the procedures specified in paragraph (g) of this AD.

Note 1:

The Boeing service bulletin refers to Spirit AeroSystems Document MAA7-70023-1, dated November 22, 2005, as an additional source of service information for accomplishing the corrective actions.

Alternative Methods of Compliance (AMOCs)

(g)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards 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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who 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.

Material Incorporated by Reference

(h) You must use Boeing Alert Service Bulletin 777-78A0056, dated April 20, 2006, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov;​; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on October 10, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate; Aircraft Certification Service.