76-09-03 LOCKHEED-CALIFORNIA COMPANY: Amendment 39-2590. Applies to Lockheed-California Company Model L-1011-385 series airplanes certificated in all categories.
Compliance required as indicated.
To prevent possible sudden in-flight depressurization due to stress corrosion failures of the hooks or related components of the C-1, C-2 or C-3 cargo doors, accomplish the following:
(a) Within the next 850 hours' time in service after the effective date of this AD, unless the modifications of paragraph (d) have been accomplished, and thereafter at intervals not to exceed 850 hours' time in service until the modifications of paragraph (d) are accomplished.
(1) Visually inspect the upper and lower hooks, clevis fittings, eccentric pins, bushings, pressure stops and the door surround structure on the C-1 and C-2 cargo doors for failures or cracks in accordance with Lockheed Service Bulletin 093-52-086, Revision 1, dated March 11, 1976 or later FAA-approved revision or an FAA approved equivalent; and
(2) Replace cracked or failed parts with serviceable parts of the same or later eligible part numbers or accomplish the modifications of paragraph (d) before further pressurized flight.
(b) Within the next 850 hours' time in service after the effective date of this AD, unless already accomplished, or unless modifications of paragraph (d) have been accomplished,
(1) Visually inspect the upper and lower hooks, clevis fittings, bushings, eccentric pins, pressure stops and door surround structure on the C-3 cargo door for failures and cracks in accordance with Lockheed Service Bulletin 093-52-086, Revision 1, dated March 11, 1976 or later FAA-approved revision or an FAA approved equivalent;
(2) Replace cracked or failed parts with serviceable parts of the same or later eligible part number, or accomplish the modifications of paragraph (d) before further pressurized flight.
(c) Within the next 1700 hours' time in service after the effectivedate of this AD, concurrent with the first or second inspection required by paragraph (a), unless already accomplished or unless modifications of paragraph (d) have been accomplished, perform a one- time rigging check of the C-1, C-2 and C-3 cargo doors and rerig as necessary to conform with rigging data in accordance with Lockheed Service Bulletin 093-52-086, Revision 1, dated March 11, 1976 or later FAA-approved revision or an equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region.
(d) Within the next 5600 hours' time in service after the effective date of this AD, unless already accomplished, replace the existing upper and lower hooks and upper eccentric pins on the C-1 and C-2 cargo doors and the lower hooks and upper pivot eccentric pins of the C-3 cargo door; change corresponding attaching hardware; repeat the visual inspections required by paragraphs (a) and (b) on the hardware retained, the pressure stops and the doors surround structure; repairas necessary; and complete a rig check of all hooks and pressure stops in accordance with Lockheed Service Bulletin 093-52-087, dated March 11, 1976 or later FAA- approved revision or an equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region.
(e) The modifications of paragraph (d) may be accomplished on the C-1 and C-2 cargo door in lieu of accomplishing the modifications required by paragraph (c) of AD 75-08-14, as amended, provided, the modifications of paragraph (d) are accomplished within the same hours' time in service after April 16, 1975 set forth by AD 75-08-14, as amended.
(f) The repetitive inspections required by paragraph (a) of this AD and by paragraph (b) of AD 75-08-14, as amended, may be discontinued after the modifications of paragraph (d) have been accomplished.
(g) For airplanes with C-1 and C-2 cargo doors having upper hooks P/N's 1517205- 107/-109 installed, compliance with paragraph (b) of AD 75-08-14, amended, may be accomplished concurrently with the initial and repetitive inspections required by paragraph (a) of this AD, provided that the upper hooks are inspected by a dye penetrant method in accordance with Lockheed Alert Service Bulletin 093-52-A079, Revision 1, dated March 26, 1975 or later FAA- approved revision or an FAA approved equivalent.
(h) Airplanes may be flown unpressurized to a base where the inspections or modifications required by this AD may be accomplished, in accordance with FARs 21.197 and 21.199.
(i) It is requested that a written report on the results of the C-3 cargo door inspections required by paragraph (b), either positive or negative, be forwarded to: Chief, Aircraft Engineering Division, FAA, Western Region, P.O. Box 92007, Worldway Postal Center, Los Angeles, CA 90009.
(Reporting approved by the Office of Management and Budget under OMB No. 04- R0174).
This amendment becomes effective May 6, 1976.