02-205. Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 777 series airplanes. This proposal would require inspection of certain aft axle pivot pins of the main landing gear (MLG) for heat damage and either reworking of damaged pins or replacement of damaged pins with new pins. This action is necessary to prevent breakage of the aft axle pivot pin of the MLG, which could overload the center axle, causing the tires to blow out upon landing, and could disengage the aft axle so that it jams the gear in the wheel well, preventing proper extension of the MLG. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by February 19, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket Number 2000-NM-333-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-333-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Stan Wood, 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

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-333-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket Number 2000-NM-333-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report indicating that a fractured aft axle pivot pin had been discovered in the main landing gear (MLG) of a Boeing Model 777 series airplane used as a flight test airplane with 488 total flight cycles. Metallurgical inspection of the aft axle pivot pin revealed heat damage to the base metal. Such heat damage, if not corrected, could cause breakage of the aft axle of the pivot pin of the MLG. A broken aft axle pivot pin could migrate from the joint, disengaging the aft axle and causing it to jam the gear in the wheel well, which could prevent proper extension of the MLG. In addition, the loss of function of the aft axle could overload the center axle, causing the tires to blow out upon landing.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing special Attention Service Bulletin 777-32-0029, dated May 18, 2000, which describes procedures for performing a visual inspection of the aft axle pivot pins of the MLG to determine their serial numbers, removal of certain pivot pins, inspection of the pivot pins for heat damage using either the Barkhausen Noise Inspection method for chromium-plated parts or the magnetic particle inspection method, and re-installation of undamaged pivot pins or replacement of damaged pivot pins with new pivot pins. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact

There are approximately 263 airplanes of the affected design in the worldwide fleet. The FAA estimates that 73 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be at least $17,520, or $240 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2000-NM-333-AD.

Applicability: Model 777 series airplanes, line numbers 1 through 263 inclusive; certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent breakage of the aft axle pivot pin of the main landing gear (MLG), which could overload the center axle, causing the tires to blow out upon landing, and could disengage the aft axle so that it jams the gear in the wheel well, preventing proper extension of the MLG, accomplish the following:

Inspection

(a) Within 18 months of the effective date of this AD: Perform the actions specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, in accordance with Boeing special Attention Service Bulletin 777-32-0029, dated May 18, 2000.

(1) For airplanes which have line numbers 1 through 68 inclusive (designated as Group 1 airplanes in the service bulletin) and on which the aft axle pivot pin of the main landing gear (MLG) has been replaced prior to the effective date of this AD: Inspect the serial number of the pivot pin.

(i) If the serial number of the pivot pin does not have the prefix of EGL, no further action is required.

(ii) If the serial number of the pivot pin does have the prefix of EGL, prior to further flight, perform the actions required by paragraph (a)(2) of this AD.

(2) For airplanes which have line numbers 69 through 263 inclusive (designated as Group 2 airplanes in the service bulletin): Remove the aft axle pivot pin, remove the lube insert from the aft axle pivot pin, and inspect the aft axle pivot pin for heat damage. The inspection must be done either by the Barkhausen Noise Inspection method for chromium-plated parts or by the magnetic particle inspection method, in accordance with the service bulletin.

(i) If heat damage is found by the inspection required by paragraph (a)(2) of this AD: Prior to further flight, re-work the existing aft axle pivot pin, re-install the existing lube insert, and re-install the re-worked aft axle pivot pin or install a new aft axle pivot pin in the MLG, in accordance with the service bulletin.

(ii) If no heat damage is found by the inspection required by paragraph (a)(2) of this AD: Prior to further flight, re-install the existing lube insert and re-install the existing aft axle pivot pin or install a new aft axle pivot pin in the MLG, in accordance with the service bulletin.

Spares

(b) After the effective date of this AD, no person shall install an aft axle pivot pin having a serial number with the prefix “EGL” in the MLG, unless the pivot pin has been inspected as required by paragraph (a) of this AD.

Alternative Methods of Compliance

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on December 28, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.