Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777 series airplanes, that requires replacement of the clevis ends on the tie rods for the center stowage bin supports with improved clevis ends. This amendment is prompted by a report that, under ultimate load conditions, the aluminum clevis ends on the tie rods for the center stowage bin supports can break. The actions specified by this AD are intended to prevent broken tie rods, which could result in the center stowage bins dropping onto the passenger seats below, causing possible injury to the occupants.

DATES:

Effective May 16, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 16, 2000.

ADDRESSES:

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, PO Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Julie Alger, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue S.W., Renton, Washington 98055-4056; telephone (425) 227-2779; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 777 series airplanes was published in the Federal Register on October 27, 1999 (64 FR 57794). That action proposed to require replacement of the clevis ends on the tie rods for the center stowage bin supports with improved clevis ends.

Explanation of New Service Information

Since the issuance of the proposal, the FAA has reviewed and approved Boeing Service Bulletin 777-25-0120, Revision 1, dated March 16, 2000. Revision 1 of the service bulletin is substantially similar to the original issue (which was referenced in the proposal as the appropriate source of service information for accomplishment of the proposed actions) and adds no additional airplanes to the effectivity listing. Revision 1 clarifies certain procedures described in the service bulletin. Accomplishment of the actions specified in Revision 1 of the service bulletin is intended to adequately address the unsafe condition described previously. Therefore, paragraph (a) of this final rule has been revised to reference Revision 1 of the service bulletin as the appropriate source of service information for the accomplishment of the requirements of that paragraph. In addition, a new “Note 2” has been added to this AD (and other notes have been renumbered accordingly) to specify that replacement of clevis ends prior to the effective date of this AD in accordance with the original issue of the service bulletin is acceptable for compliance with paragraph (a) of this AD.

Explanation of Change to Applicability

Operators should note that Revision 1 of the service bulletin deletes three airplanes from the effectivity listing. The intent of the service bulletin was accomplished prior to delivery of those airplanes. Therefore, the applicability statement of this final rule has been revised accordingly.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

No Objection to the Proposal

One commenter states that it has no objection to the proposed rule.

Compliance Time May Impact Service

One commenter states that it agrees with the proposed compliance time of four years. However, the commenter is concerned that the proposed replacement is intended to be accomplished during a scheduled maintenance visit, and, therefore, the replacement will not be accomplished on some airplanes for three or four years. The commenter also states that any change to the proposed time of compliance would impact service to the public. The commenter makes no specific request for a change to this AD.

The FAA acknowledges the commenter's point that the replacement required by this AD has the potential to impact service to the public. In developing an appropriate compliance time for this action, the FAA considered not only the manufacturer's recommendation (as specified in Boeing Service Bulletin 777-25-0120, dated February 11, 1999), but also the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the modification. In consideration of these items, the FAA has determined that four years represents an appropriate interval of time allowable wherein the modifications can be accomplished during scheduled maintenance intervals for the majority of affected operators, and an acceptable level of safety can be maintained. No change to the final rule is necessary in this regard.

Request To Increase Cost Estimate

One commenter estimates that the replacement of clevis ends specified in Boeing Service Bulletin 777-25-0120 will require 44 work hours instead of the 20 work hours estimated in the service bulletin. (The cost estimate in the NPRM for accomplishment of the replacement on Model 777-200 series airplanes is 12 work hours, excluding the time to gain access and close up.) The FAA infers that the commenter is requesting that the cost estimate be increased in the final rule.

The FAA does not concur with the commenter's request. The number of work hours necessary to accomplish the required actions, specified as 12 in the cost impact information below, was provided to the FAA by the manufacturer based on the best data available to date. This number represents the “direct” costs of the specific actions required by this AD: the time necessary to perform only the actions actually required by this AD. The FAA recognizes that, in accomplishing the requirements of any AD, operators may incur “incidental” costs in addition to the “direct” costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental costs, such as the time required to gain access and close up; planning time; or time necessitated by other administrative actions. Because incidental costs may vary significantly from operator to operator, they are almost impossible to calculate. No change to the final rule is necessary in this regard.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

There are approximately 168 Model 777-200 and 16 Model 777-300 series airplanes of the affected design in the worldwide fleet.

The FAA estimates that 41 Model 777-200 airplanes of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per airplane to accomplish the required replacement of clevis ends, and that the average labor rate is $60 per work hour. Required parts will cost approximately $15,938 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $682,978, or $16,658 per airplane.

Currently, there are no Model 777-300 airplanes on the U.S. Register that will be affected by this AD. However, should an unmodified airplane be imported and placed on the U.S. Register in the future, it would take approximately 17 work hours per airplane to accomplish the actions required by this AD, at an average labor rate of $60 per work hour. Required parts would cost approximately $18,457 per airplane. Based on these figures, the cost impact of the replacement required by this AD on these airplanes is estimated to be $19,477 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) Is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption “ADDRESSES.”

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

2000-07-08 Boeing: Amendment 39-11662. Docket 99-NM-232-AD.

Applicability: Model 777 series airplanes, line numbers 2 through 103 inclusive, 105 through 119 inclusive, 121 through 161 inclusive, 163 through 177 inclusive, and 179 through 186 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 (b) 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 broken tie rods, which could result in the center stowage bins dropping onto the passenger seats below, causing possible injury to the occupants, accomplish the following:

Replacement

(a) Within 4 years after the effective date of this AD, replace the aluminum clevis ends on the tie rods for the center stowage bin supports with new steel clevis ends, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 777-25-0120, Revision 1, dated March 16, 2000.

Note 2:

Accomplishment of the replacement of clevis ends with new steel clevis ends prior to the effective date of this AD in accordance with Boeing Service Bulletin 777-25-0120, dated February 11, 1999, is acceptable for compliance with paragraph (a) of this AD.

Alternative Methods of Compliance

(b) 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, Transport Airplane Directorate. 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 3:

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

(c) 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.

Incorporation by Reference

(d) The replacement shall be done in accordance with Boeing Service Bulletin 777-25-0120, Revision 1, dated March 16, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(e) This amendment becomes effective on May 16, 2000.