04-19925. Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A, KDC-10), DC-10-40, DC-10-40F, MD-10-10F, and MD-10-30F Airplanes; and Model MD-11, and MD-11F 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 airplane models. That action would have superseded an existing AD to require that the repetitive inspections of the numbers 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions, if necessary; be performed at reduced intervals. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) has determined that the proposed inspection requirements are identical to the inspection requirements of another existing AD. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT:

Ken Sujishi, 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-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A, KDC-10), DC-10-40, and DC-10-40F airplanes; and Model MD-10-10F and MD-10-30F airplanes, was published in the Federal Register as a notice of proposed rulemaking (NPRM) on January 22, 2004 (69 FR 3036). The proposed rule would have superseded AD 2001-14-08, amendment 39-12319 (66 FR 36441, July 12, 2001), to require that the repetitive inspections of the numbers 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions, if necessary; be performed at reduced intervals (i.e., from 6,000 flight hours to 2,500 flight hours). That action was prompted by a report from Boeing that the original compliance time was not adequate, because another incident of failure of an electric motor of the auxiliary hydraulic pump had occurred during the interval between repetitive inspections. The proposed actions were intended to prevent various failures of electric motors of the auxiliary hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure.

Actions That Occurred Since the NPRM Was Issued

Since the issuance of that NPRM, we issued AD 2004-05-20, amendment 39-13515 (69 FR 11504, March 11, 2004), applicable to certain McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, and DC-10-40F airplanes; Model MD-10-10F and MD-10-30F airplanes; and Model MD-11 and MD-11F airplanes. That AD requires modification of the installation wiring for the electric motor operated auxiliary hydraulic pumps in the right wheel well area of the main landing gear, and repetitive inspections (at intervals not to exceed 2,500 flight hours) of the numbers 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions if necessary. That action was prompted by several reports of failure of the auxiliary hydraulic pump systems. The requirements of that AD are intended to prevent failure of the electric motors of the hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure.

The repetitive inspections required by AD 2004-05-20 are identical to those proposed in the NPRM. Accomplishment of the modification and repetitive inspections requirements of AD 2004-05-20 adequately addresses the identified unsafe condition.

FAA's Conclusions

Upon further consideration, we have determined that the proposed inspection requirements of the NPRM are identical to the inspection requirements of AD 2004-05-20. 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.

Other Relevant Rulemaking

For the reasons discussed previously, we are also planning on rescinding AD 2001-14-08 in a separate rulemaking action.

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 2003-NM-119-AD, published in the Federal Register on January 22, 2004 (69 FR 3036), is withdrawn.

Issued in Renton, Washington, on August 20, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.