01-19262. Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Proposed rule; withdrawal.

SUMMARY:

This action withdraws a notice of proposed rulemaking (NPRM) that proposed a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes. That action would have required repetitive inspections of the side load underwing fitting bushings for broken sealant or bushing migration, and corrective action, if necessary. That action also would have provided for optional terminating action in lieu of repetitive inspections. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) has received new data and has issued alternative rulemaking action. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT:

John D. Craycraft, 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:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, was published in the Federal Register as a Notice of Proposed Rulemaking (NPRM) on November 24, 1999 (64 FR 66119). The proposed rule would have required repetitive inspections of the side load underwing fitting bushings for broken sealant or bushing migration, and corrective action, if necessary. The proposed rule also would have provided for optional terminating action in lieu of repetitive inspections. The proposed rule was prompted by reports of migrated bushings and corrosion on the side load fittings. The proposed actions were intended to prevent corrosion in the side load underwing fitting, which could result in cracking and consequent reduced structural integrity of the wing strut.

Actions Since Issuance of the NPRM

Since the issuance of that NPRM on November 18, 1999, the FAA has issued alternative rulemaking action, which, in addition to comments we have received in response to the NPRM, has caused us to reconsider our previous position on this rulemaking action.

We have considered the comments and recommendations we received. Although one commenter supports the NPRM as proposed, eight other commenters object to it for various reasons. Some of those reasons follow:

• Bushing migration does not present an immediate safety concern, and no significant corrosion has been found in the side load underwing fitting. For these reasons, the commenters believe that the inspections specified in the NPRM are unnecessary.
• The cost estimates in the NPRM are too low because of the extensive work required, special tooling, and the resultant impact on scheduled service. Operators recommend increasing the cost estimates to include additional costs for labor, access and closeup, and special tooling and equipment.
• The compliance times for the inspections, as specified in the NPRM, would put affected airplanes out of service for an extended period. One commenter states that the manufacturer would not be able to provide an adequate number of kits within the specified compliance time. Operators recommend that the compliance times coincide with other existing maintenance programs such as the Strut Improvement Program (SIP) and the Corrosion Prevention and Control Program (CPCP).
• Removing and reinstalling the wing struts is not a routine task performed at regular maintenance intervals. In addition, the frequency of strut removal specified in the NPRM would severely impact airline schedules. The manufacturer recommends removing the strut only during a CPCP inspection, which is accomplished at or before 18 years in service. Limiting strut removal will reduce the element of human error, structural damage to the lug areas, and improper sealing of the bushings.
• The repetitive inspections specified by paragraph (b) of the NPRM should be allowed to continue until incorporation of the SIP.

FAA's Determination

Since the issuance of the NPRM, the FAA has issued three ADs to require accomplishment of the 767 SIP. Although the NPRM requires repetitive inspections and corrective action if a broken sealant or bushing migration is detected, the new ADs require modification of the nacelle strut and wing structure on both the left and right sides of the airplane. The FAA adds that the discrepancy (broken sealant or bushing migration) specified in the NPRM also is addressed by the actions included in the 767 SIP. In addition, since issuance of Boeing Service Bulletin 767-57-0063, dated May 7, 1998, Boeing has provided to the FAA additional data indicating that the recommended compliance times listed in that service bulletin were overly conservative. For these reasons, the FAA has determined that issuance of the NPRM is no longer necessary since the intent of that AD will be accomplished by the following previously issued ADs:

• AD 2001-02-07, amendment 39-12091 (66 FR 8085, January 29, 2001).
• AD 2001-06-12, amendment 39-12159 (65 FR 17492, April 2, 2001).
• AD 2000-19-09, amendment 39-11910 (65 FR 58641, October 2, 2000).

FAA's Conclusions

Upon further consideration, the FAA has determined that, in light of the above information, the identified unsafe condition has been addressed. Accordingly, the NPRM is hereby withdrawn.

Withdrawal of this NPRM constitutes only such action, and does not preclude the agency from issuing another action in the future, nor does it commit the agency to any course of action in the future.

Regulatory Impact

Since this action only withdraws a notice of proposed rulemaking, it is neither a proposed nor a final rule and therefore is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Withdrawal

Accordingly, the notice of proposed rulemaking, Docket 99-NM-132-AD, published in the Federal Register on November 24, 1999 (64 FR 66119), is withdrawn.

Issued in Renton, Washington, on July 26, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.