E6-8123. Airworthiness Directives; Boeing Model 777-200, -300, and -300ER Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 777-200, -300, and -300ER series airplanes. This proposed AD would require replacement of the gimbal plates of the left and right outboard trailing edge flaps with improved gimbal plates and other specified actions. This proposed AD results from a broken pivot link found on the inboard support for the outboard trailing edge flap. We are proposing this AD to prevent disconnection of the drive arm from its drive gimbal, due to a broken pivot link on an outboard flap support, which could result in unexpected roll of the airplane and loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by July 10, 2006.

ADDRESSES:

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

FOR FURTHER INFORMATION CONTACT:

Gary Oltman, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-24891; Directorate Identifier 2006-NM-080-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

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 proposed 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 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.

Discussion

We have received a report indicating that a broken pivot link was found on the inboard support for the outboard trailing edge flap on a Boeing Model 777-300 series airplane. That broken pivot link was found after an incident where, during approach, the flightcrew received the FLAPS PRIMARY and FLAPS SKEW messages, and the airplane rolled slightly to the left. The flightcrew was able to land the airplane without difficulty. Investigation revealed that a broken pivot link on outboard flap support number 2 caused an increased load on the drive arm assembly of support number 1. The increased load caused the drive arm gimbal plates to disconnect from the drive gimbal, which led to a skewed outboard flap. This condition, if not corrected, could result in unexpected roll of the airplane and loss of control of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 777-27A0073, dated March 30, 2006. The service bulletin describes procedures for replacing the gimbal plates of the left and right outboard trailing edge flaps with improved gimbal plates and doing other specified actions. The other specified actions include adjusting the gimbal plate shims, rotating the upper gimbal bushing, installing a new grease fitting, adjusting the bulkhead fitting shim, changing the flap skew detection bracket assembly, lubricating the outboard transmission, ballscrews, and gimbal of the outboard flaps, and doing the adjustment/test of the trailing edge flap system. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

There are about 546 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 145 airplanes of U.S. registry. The proposed actions would take about 153 work hours per airplane, at an average labor rate of $80 per work hour. Required parts would cost about $69,850 per airplane. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $11,903,050, or $82,090 per airplane.

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 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 that the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed 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
• 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

BOEING: Docket No. FAA-2006-24891; Directorate Identifier 2006-NM-080-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by July 10, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 777-200, -300, and -300ER series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 777-27A0073, dated March 30, 2006.

Unsafe Condition

(d) This AD results from a broken pivot link found on the inboard support for the outboard trailing edge flap. We are issuing this AD to prevent disconnection of the drive arm from its drive gimbal, due to a broken pivot link on an outboard flap support, which could result in unexpected roll of the airplane and loss of control of the airplane.

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.

Replacement of Gimbal Plates

(f) Within 24 months after the effective date of this AD, replace the gimbal plates of the left and right outboard trailing edge flaps with improved gimbal plates, and do the other specified actions before further flight after the replacement, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 777-27A0073, dated March 30, 2006.

Parts Installation

(g) As of the effective date of this AD, no person may install a gimbal plate, part numbers 113W1112-3, 113W1112-4, 113W1212-3, and 113W1212-4, on any airplane, unless it has been modified in accordance with paragraph (f) of this AD.

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 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, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on May 18, 2006.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.