AD 95-04-07 R1

On February 16, 1995, the FAA issued AD 95-04-07, amendment 39-9159 (60 FR 11617, March 2, 1995), which is applicable to certain McDonnell Douglas Model DC-10-10, -15, and -30 airplanes, and KC-10A (military) airplanes. That AD requires visual inspections to determine the condition of the lockwires on the forward engine mount bolts on engines 1, 2, and 3, and correction of discrepancies found. That AD also requires that operators report the results of the visual inspections to the FAA. Additionally, that AD provides for the termination of the visual inspections by installing retainers on the engine mount bolts on Model DC-10-30 airplanes and KC-10A airplanes in accordance with Revision 6 of McDonnell Douglas DC-10 Service Bulletin 71-133, dated June 30, 1992. That action was prompted by reports indicating that the lockwires on the forward engine mount bolts were stretched or broken. The actions required by that AD are intended to prevent broken lockwires, which could result in loosening of the engine mount bolts, and subsequent separation of the engine from the airplane.

Since the issuance of that AD, the FAA has received communication from affected operators indicating that the procedures for accomplishing the optional terminating action on engines 1, 2, and 3 are unclear. These operators have indicated that the service information contained in McDonnell Douglas DC-10 Service Bulletin 71-133, Revision 6, dated June 30, 1992 (which is referenced in the AD as the appropriate source of service information) does not describe procedures to accomplish the optional terminating action for engine 2. These operators have requested that the FAA clarify AD 95-04-07 to indicate exactly how to accomplish the optional terminating action for engine 2.

In considering this request, and upon further review of the procedures contained in that service bulletin, the FAA concurs that clarification is necessary.

It was the FAA's intent to include all engines in the provision for the optional terminating action. As such, the intent of paragraph (c) was to allow termination of the inspection for any engine on which retainers on the engine mount bolts had been installed. The FAA finds that although Figure 6 of the service bulletin does not describe procedures for installing retainers on the forward engine mount bolts on engine 2, the method for installing the retainers on engine 2 does not differ from the method for installing the retainers on engines 1 and 3, which is described in Figure 6 of the service bulletin. Therefore, the FAA has determined that paragraph (c) must be revised to reference Figure 6 of McDonnell Douglas DC-10 Service Bulletin 71-133, Revision 6, dated June 30, 1992, as the appropriate source of service information to accomplish the optional terminating action on engine 2, as well as engines 1 and 3.

Action is taken herein to clarify AD 95-04-07 and to correctly add the AD as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13).

The final rule is being reprinted in its entirety for the convenience of affected operators. The effective date of the rule remains March 17, 1995.

Since this action only clarifies the procedures for accomplishing an optional action contained in a final rule, it has no adverse economic impact and imposes no additional burden on any person. Therefore, notice and public procedures hereon are unnecessary.

List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment 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:

PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g);and 14 CFR 11.89.

§ 39.13 - (Amended) 2. Section 39.13 is amended by removing amendment 39-9159 (60 FR 11617, March 2, 1995), and by adding a new airworthiness directive (AD), amendment 39-9317, to read as follows: