Airworthiness Directives; Lockheed Model L-1011-385 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 all Lockheed Model L-1011-385 series airplanes. That action would have required repetitive leak tests of the lavatory drain systems and repair, if necessary; installation of a lever lock cap, vacuum breaker check valve or flush/fill line ball valve on the flush/fill line; periodic seal changes; and replacement of “donut” type waste drain valves installed in the waste drain system. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) has reviewed existing data and determined that, for airplanes without a history of engine damage resulting from “blue ice,” such as Lockheed Model L-1011-385 series airplanes, the hazard of “blue ice” to persons and property may be more appropriately addressed through means other than AD action. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT:

Hector Hernandez, Aerospace Engineer, Systems and Equipment Branch, ACE-119A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770) 703-6069; fax (770) 703-6097.

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 all Lockheed Model 1011-385 series airplanes, was published in the Federal Register as a Notice of Proposed Rulemaking (NPRM) on September 3, 1998 (63 FR 46927). The proposed rule would have required repetitive leak tests of the lavatory drain systems and repair, if necessary; installation of a lever lock cap, vacuum breaker check valve or flush/fill line ball valve on the flush/fill line; periodic seal changes; and replacement of “donut” type waste drain valves installed in the waste drain system. That action was prompted by continuing reports of damage to engines, airframes, and to property on the ground, caused by “blue ice” that forms from leaking lavatory drain systems on transport category airplanes and subsequently dislodges from the airplane fuselage. The proposed actions were intended to prevent such damage associated with the problems of “blue ice.”

Comments Received Regarding the NPRM

Several commenters request various changes to the NPRM. In light of the fact that we are withdrawing the NPRM, responses to those requests are unnecessary, except as discussed below.

Request To Withdraw the NPRM

One commenter, American Trans Air, suggests several reasons why an AD is unnecessary for Lockheed Model L-1011-385 series airplanes. The commenter points out that Model L-1011-385 series airplanes do not have the adverse service history with “blue ice” leakage that some other airplane models have. The commenter suggests that this may be due, in part, to certain basic differences between the forward lavatory waste system of Model L-1011-385 series airplanes and certain other airplanes such as Boeing Model 727 and 737 airplanes. In support of this statement, the commenter submitted a drawing showing basic differences between the forward lavatory waste system of Model L-1011-385 series airplanes and Model 727 series airplanes. Additionally, the commenter states that normal preflight inspections for blue streaks on the fuselage are adequate for detecting valve leakage without requiring mandatory action.

The FAA infers that the commenter is requesting that the NPRM be withdrawn. We agree with the commenter's statements. In addition, for the reasons stated below, we are withdrawing the NPRM.

Actions That Occurred Since the NPRM Was Issued

Since the issuance of that NPRM, we have determined that it is unnecessary to regulate the actions proposed in the NPRM for certain airplane models equipped with potable water systems and lavatory fill and drain systems, including Model L1011-385 series airplanes. Based on analysis of various service information and data accumulated in the last several years, we have determined that, for airplanes without a history of engine damage resulting from “blue ice,” such as Model L-1011-385 series airplanes, the hazards of “blue ice” to persons or property on the ground may be more appropriately addressed by the issuance of a special airworthiness information bulletin (SAIB).

FAA's Conclusions

Upon further consideration, we have issued SAIB NM-06-57, dated July 27, 2006, which contains recommendations for owners and operators of certain transport category airplanes regarding maintenance and ground handling practices and procedures that are intended to adequately address issues involving “blue ice.” 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 98-NM-200-AD, published in the Federal Register on September 3, 1998 (63 FR 46927), is withdrawn.