64-07-04 LOCKHEED: Amdt. 705 Part 507 Federal Register March 14, 1964. Applies to All Models 49, 149, 649, 649A, 749, 749A, 1049-54, 1049C, 1049D, 1049E, 1049G and 1049H Series Aircraft.
Compliance required as indicated.
(a) To insure that the bolts in the parallelogram linkages of the primary flight control boost systems remain secured and safetied, accomplish the following within 400 hours' time in service after the effective date of this AD, unless previously accomplished.
(1) Replace the five castellated nuts in each of the four parallelogram linkages between the boost valve and boost mechanism of each of the boost systems with self-locking castellated nuts and cotter pins using MS-17825(WEP) in lieu of AN 310 nuts and MS- 17826(WEP) in lieu of AN 320 nuts or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region.
(2) All torque requirements that applied to the AN 310 and 320 castellated nuts also apply to the MS-17825(WEP) and MS-17826(WEP) self-locking castellated nuts, respectively.
(b) Replace the self-locking castellated nuts with new self-locking castellated nuts prior to exceeding the reusability limits specified by the nut manufacturer.
(Lockheed Service Information Letter 514, dated November 27, 1963, covers this same subject.)
This directive effective April 14, 1964.