AD 93-24-12 ACTIVE

93-24-12 LOCKHEED: Amendment 39-8761. Docket 92-NM-199-AD.
Applicability: Model L-1011-385-1, -385-1-14, -385-1-15, and -385-3 series airplanes; as listed in Lockheed Service Bulletin 093-52-155, Revision 1, dated October 23, 1989, and Lockheed Service Bulletin 093-53-252, Revision 2, dated April 25, 1989; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the cargo door latching mechanism, which could lead to the cargo door opening during flight and resulting in rapid decompression of the airplane, accomplish the following:

(a) For airplanes listed in Lockheed Service Bulletin 093-52-155, Revision 1, dated October 23, 1989: Prior to the accumulation of 8,000 total landings, or within 1,800 landings after the effective date of this AD, whichever occurs later, perform a one-time visual inspection to detect excessive thickness of the shims installed under the hinges of the C-1A cargo door in accordance with Lockheed Service Bulletin 093-52-155, Revision 1, dated October 23, 1989. Accomplishment of this inspection is considered to constitute compliance with the similar inspection requirements of AD 91-05-05, Amendment 39-6878, for this same area.

(1) If any shim is found that exceeds 0.125 inch for single leg hinges, or 0.140 inch for double leg hinges, prior to further flight, install a structural doubler on the hinge and a new shim, in accordance with the procedures described in the service bulletin.

(2) If any shim is found that equals or is less than 0.125 inch for single leg hinges, or 0.140 inch for double leg hinges, no further action is required for that shim.

(b) For airplanes listed in Lockheed Service Bulletin 093-53-252, Revision 2, dated April 25, 1989: Prior to the accumulation of 8,000 total landings or within 1,800 landings after the effective date of this AD, whichever occurs later, inspect the lower sill latch fittings and serrated plates ofthe C-1A cargo door for cracks and corrosion, in accordance with Lockheed Service Bulletin 093-53-252, Revision 2, dated April 25, 1989. Additionally, perform a hardness test to determine the condition of the heat treatment of the serrated plates.

NOTE 1: Lockheed Service Bulletin 093-53-252, Revision 2, dated April 25, 1989, refers to Lockheed Service Modification/Kit Drawing 1646587, Revision C, dated August 14, 1987, for additional information concerning the inspection procedures, corrosion limit specifications, crack limit specifications, and modifications relative to the requirements of this paragraph.

(1) If any cracked latch fitting is found, prior to further flight, replace the latch fitting with a serviceable part.

(2) If any corroded latch fitting is found, prior to further flight, replace the latch fitting with a serviceable part. However, if the latch fitting is of a condition suitable for refurbishment, as referred to in the service bulletin, it may berefurbished and reused.

(3) If any cracked serrated plate is found, prior to further flight, replace it with a serviceable part. However, if the cracked serrated plate is determined to be suitable for reuse, as referred to in the service bulletin, it may be reinstalled for an additional 1,000 landings only, at which time it then must be replaced.

(4) If no crack or corrosion is found in any serrated plate, prior to further flight, apply cadmium plating to the plate in accordance with the service bulletin.

(5) If any serrated plate is found with improper heat treatment, prior to further flight, reprocess the plate or replace the plate with a serviceable part in accordance with the service bulletin.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Operators shall submit theirrequests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

(d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(e) The inspection and installation shall be done in accordance with Lockheed Service Bulletin 093-52-155, Revision 1, dated October 23, 1989. The inspection, hardness test, replacement, refurbishment, reinstallation, application of cadmium plating, and reprocessing shall be done in accordance with Lockheed Service Bulletin 093-53-252, Revision 2, dated April 25, 1989, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 4-5
2
April 25,1989
2-3
Original
March 15, 1988

The incorporation by reference of these documents was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Lockheed Western Export Company (LWEC), Dept. 693, Zone 0755, 86 South Cobb Drive, Marietta, Georgia 30063. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office (ACO), 1669 Phoenix Parkway, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on January 10, 1994.