05-613. Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 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 McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. That action would have required installing shield assemblies for power feeder cables in the forward and aft lower cargo compartments, and installing an additional shield for the power feeder cable of the auxiliary power unit in the aft lower cargo compartment. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) has determined that the proposed requirements are included in the requirements of another existing AD; the NPRM does not contain any new requirements beyond those of the existing AD. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT:

Elvin K. Wheeler, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 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 McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes; was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 30, 2003 (68 FR 61772). The proposed rule would have required installing shield assemblies for power feeder cables in the forward and aft lower cargo compartments, and installing an additional shield for the power feeder cable of the auxiliary power unit in the aft lower cargo compartment. That action was prompted by several incidents of migration of power feeder cable troughs on McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. The proposed actions were intended to prevent a cable from chafing against an edge of a lightening hole, which could result in electrical arcing, and consequent smoke/fire in the lower cargo compartments.

Response to Comments

We have considered the comments that have been submitted on the proposed AD. One commenter points out that an existing AD, AD 94-09-02, amendment 39-8890 (59 FR 18720, April 20, 1994), currently requires accomplishment of the original issue of Boeing Service Bulletin MD80-24-100. The commenter further states that all affected airplanes listed in Revision 04 of that service bulletin (referenced as the appropriate source of service information in the proposed rule) were affected by the previous revisions of that service bulletin, and that the proposed rule contains no new requirements beyond those required by the existing AD.

We agree. We have determined that the requirements of the proposed rule are included in the requirements of another existing AD. The existing AD, AD 94-09-02, is applicable to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes; and Model MD-88 airplanes; as listed in McDonnell Douglas MD-80 Service Bulletin 24-94, Revision 1, dated May 28, 1987, and McDonnell Douglas Model MD-80 Service Bulletin 24-100, dated March 30, 1988. That AD requires an inspection to detect damage of the auxiliary power unit (APU) power feeder cable installation, repair of damaged cables, modification of the cable installation, and an inspection of previously modified airplanes to determine whether a spacer or “stand off” has been installed, and installation of those items, if necessary. That action was prompted by reports of generator power feeder cables electrically shorting to the airplane structure due to chafing. The requirements of that AD are intended to prevent the APU power feeder cable from chafing against adjacent structures, which could result in electrical shorting and arcing, and a fire below the cabin floor.

Additionally, AD 94-09-02 references McDonnell Douglas MD-80 Service Bulletin 24-100, dated March 30, 1988, as the appropriate source of service information for accomplishing the modification. The proposed rule references McDonnell Douglas Alert Service Bulletin MD80-24A100, Revision 04, dated January 24, 2000, as the appropriate source of service information for accomplishing the modification (installing shield assemblies for power feeder cables). Revision 04 was issued merely to elevate the service bulletin to the “alert” status and to reference AD 94-09-02; no additional work is required. All airplanes affected by Revision 04 are also affected by the previous revisions of the service bulletin.

The proposed rule does not contain any new requirements beyond those required by AD 94-09-02. Accomplishment of the requirements of AD 94-09-02 adequately addresses the identified unsafe condition.

FAA's Conclusions

Upon further consideration, the FAA has determined that the proposed requirements are included in the requirements of another existing AD; the proposed rule does not contain any new requirements beyond those of the existing AD. Accordingly, the proposed rule 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 2000-NM-168-AD, published in the Federal Register on October 30, 2003 (68 FR 61772), is withdrawn.

Issued in Renton, Washington, on January 3, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.