79-22-05 LOCKHEED CALIFORNIA: Amendment 39-3602. Applies to Model L- 1011-385 series airplanes certificated in all categories.
Compliance required as indicated unless already accomplished.
To prevent rapid loss of cabin pressurization in flight, accomplish the following:
(a) Within 800 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 800 hours' time in service until modified in accordance with paragraph (b) of this AD, inspect forward and aft outflow valve gates for delamination in accordance with the instructions contained in Lockheed Service Bulletin No. 093-21-157 dated May 1, 1979, Section 2B ("Full inspection of outflow valves"). Gates found defective must be removed and replaced with a part free from bond joint separation prior to further flight.
(b) Within 2400 hours' time in service after the effective date of this AD, modify the outflow valve assemblies in accordance with Hamilton Standard Service Bulletin 21-1141 dated March 28, 1979.
(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes in pressurized flight to a base for the accomplishment of inspections or modifications required by this AD. No special flight permit is required to operate the airplane unpressurized to a base for the accomplishment of inspections or modifications required by this AD.
(d) Alternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.
This amendment becomes effective December 6, 1979.