85-20-02 LOCKHEED-CALIFORNIA COMPANY: Amendment 39-5144. Applies to Lockheed Model L-1011 series airplanes, certificated in any category, incorporating Kevlar/Nomex honeycomb elevator trailing edge panels. Compliance required as indicated, unless previously accomplished.
To prevent the potential of major structural damage to the airplane due to flutter divergence as a result of water retention in the elevator trailing edge panels, accomplish the following:
a. Within 300 hours time-in-service after the effective date of this AD, inspect by X- ray, moisture meter, or in-situ balance check, the elevator trailing edges for water entrapment in accordance with Lockheed Service Bulletin 093-55-026 dated November 20, 1984, or later FAA approved revision:
1. If no water is detected and the trailing edge has less than 20,000 hours time-in-service, reinspect in accordance with paragraph (a) at intervals not to exceed 3,500 hours time-in-service.
2. If no water is detected and the trailing edge has 20,000 or more hours time-in-service, reinspect in accordance with paragraph (a) at intervals not to exceed 7,000 hours time-in-service.
3. If water is present and the calculated or measured unbalance is within allowable limits, reinspect in accordance with paragraph (a) at intervals not to exceed 1,100 hours time-in-service.
4. If water is present and the total elevator unbalance cannot be brought within allowable limits, replace the trailing edge panel or panels before further flight.
b. If the trailing edge is replaced by a trailing edge part number 1580585-103 or - 105, within 3,500 hours time-in-service after the replacement inspect in accordance with paragraph (a) and reinspect in accordance with paragraphs (a)(1), (a)(2), or (a)(3).
c. The repetitive inspections required by paragraphs (a)(1), (a)(2), and (a)(3) may be discontinued after the trailing edge is modified in accordance with Lockheed Service Bulletin 093- 55-027, dated November 20, 1984, or later FAA-approved revision.
d. Alternate means of compliance with this AD which provide an acceptable level of safety may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.
e. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a base for accomplishment of inspections or modifications required by this AD.
All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Lockheed-California Company, P.O. Box 551, Burbank, California 91520, Attention: Commercial Support Contracts, Dept. 63-11, U-33, B-1. These documents also may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California.
This amendment becomes effective November 12, 1985.