AD 2000-02-19

Effective March 9, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 9, 2000.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. 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.

Walter Sippel, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 90-02-16, amendment 39-6452 (55 FR 602, January 8, 1990), which is applicable to certain Boeing Model 727 series airplanes, was published in the Federal Register on August 10, 1999 (64 FR 43318). The action proposed to continue to require repetitive inspections of the front spar web between the upper and lower seals of the center section of the wings, and repair, if necessary. That action also proposed to require a new terminating modification for the repetitive inspections, and, for certain airplanes, new repetitive inspections to detect discrepancies of the front spar web.

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

One commenter supports the proposed rule.

One commenter, the manufacturer, requests that the proposed rule be revised to allow accomplishment of repetitive high frequency eddy current (HFEC) inspections to detect cracks in the front spar web, in lieu of the repetitive detailed visual inspections specified in paragraph (a) of the proposed rule. (In the proposed rule, the FAA stated that this AD would not provide for an HFEC inspection in lieu of the detailed visual inspection because Boeing Service Bulletin 727-57-0177, dated December 22, 1988, does not contain procedures for such an HFEC inspection, and, without such procedures, the FAA could not be sure that an HFEC inspection would detect cracks in a timely manner.) The commenter states that the option of an HFEC inspection would give operators more flexibility and reduce requests to the FAA for an alternative method of compliance. The commenter provides a reference for procedures for performing an HFEC inspection, and suggests a repetitive interval of 4,500 flight cycles. The commenter also states that it is revising Boeing Service Bulletin 727-57-0177 to incorporate procedures for an HFEC inspection and requests that the FAA delay issuance of the final rule until the release of Revision 4 of the service bulletin.

The FAA concurs with the commenter's requests. Since the issuance of the notice of proposed rulemaking (NPRM), the FAA has reviewed and approved Boeing Service Bulletin 727-57-0177, Revision 4, dated October 28, 1999. Revision 4 of the service bulletin is essentially similar to Revision 3 of the service bulletin, dated February 15, 1996. (Revision 3 of the service bulletin was cited in the NPRM as an appropriate source of service information for accomplishment of the proposed actions.) However, Revision 4 of the service bulletin also incorporates procedures for accomplishment of an HFEC inspection as an alternative to the close visual inspection. The FAA finds that the HFEC inspection described in the service bulletin would ensure that any cracks are detected in a timely manner. Therefore, paragraph (a) of this final rule has been revised to provide for accomplishment of repetitive HFEC inspections in lieu of the repetitive detailed visual inspection proposed in the NPRM. For clarity, paragraphs (a)(1) and (a)(2) have been added to specify appropriate sources of service information and repetitive inspection intervals for the two types of inspection. Also, the cost impact section of the final rule has been revised to provide an estimate of the cost for the HFEC inspection. In addition, paragraphs (b), (c), (d), and (e) of this final rule have been revised to allow accomplishment of the actions specified in those paragraphs in accordance with Revision 4 of the service bulletin.

One commenter requests that a reference to AD 90-02-15 in the “Alternative Method of Compliance” section of the NPRM be revised to refer to AD 90-02-16. The FAA concurs with the commenter's request and acknowledges that the correct reference should have been to AD 90-02-16. Paragraph (g)(2) of this AD has been revised accordingly.

The same commenter requests that a reference to Boeing Model 747 series airplanes in the “Other Relevant Rulemaking” section in the preamble of the NPRM be revised to refer instead to Boeing Model 727 series airplanes. The FAA acknowledges that the correct reference should have been to Boeing Model 727 series airplanes; however, that section is not restated in the final rule and, therefore, no change to the final rule is necessary in this regard.

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 described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

There are approximately 1,524 Model 727 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,098 airplanes of U.S. registry will be affected by this AD.

The detailed visual inspection that is currently required by AD 90-02-16, and retained in this AD as one option for compliance, and the HFEC inspection that may be accomplished in lieu of the detailed visual inspection, take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of either the currently required detailed visual or the HFEC inspection on U.S. operators is estimated to be $197,640, or $180 per airplane, per inspection cycle.

The modification that is required by this new AD will take approximately 360 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $1,430 per airplane. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $25,286,940, or $23,030 per airplane.

The visual inspection that is required for certain airplanes in this new AD action will take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this inspection on U.S. operators is estimated to be $60 per airplane, per inspection cycle.

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.

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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.

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:

1. The authority citation for part 39 continues to read as follows: