AD 75-08-12

75-08-12 HUGHES HELICOPTERS: Amendment 39-2162. Applies to Hughes 269 series helicopters certificated in all categories, including military model TH-55A, which are equipped with linear clutch actuators, P/N DL 1020M81C(12V), 269A4564, or DL 1020M82C(28V), including those helicopters on which Hughes Service Information Notice No. N-126, dated February 24, 1975, has been accomplished.

(A) Prior to further flight, unless previously accomplished, remove the actuator and cover at the lug end of the linear clutch actuator in accordance with Hughes 269 series Maintenance Manual of Instructions, issued April 1973, Revision No. 2, January 1, 1974.

(A)(1) Visually identify the markings on the four number 4-40 Allen screw heads which secure the lug to the housing. If any retainer screw has a single band of vertical lines around the outside diameter of the raised head, mutilate and discard the screw. Replace any retainer screw having such vertical lines with new screws having either of the following part numbers, and torque to five to seven inch-pounds: New Ny-Lock P/N P60HS440-12C or new Simmonds P/N S6370CESCS4-12.

(A)(2) Operators who have complied with paragraph "d", per Hughes Service Information Notice No. N-126, dated February 24, 1975, by installing these new screws, are not required to repeat the replacement of the new screws if the procedures of paragraph (A)(1) of this AD have been followed.

(A)(3) If the identifying markings on the outside diameter of the raised head consist of anything other than the single band of vertical lines, such as cross hatched band, double band of vertical lines, etc., the retainer screws need not be replaced.

(B) After complying with paragraphs (A)(1), (A)(2), and (A)(3), as applicable, identify the actuators by hand impression stamping the letter "B" on the bottom line of the actuator data plate.

(C) Reassemble and install the actuator in accordance with the Hughes Maintenance Manual of Instructions.(D) Record inspections and modifications per this AD in aircraft maintenance records in accordance with FAR 43.9.

(E) Helicopters may be flown to a base where maintenance may be performed to comply with this AD per FAR's 21.197 and 21.199.

(F) Equivalent inspection and modification procedures may be approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment is effective April 14, 1975, for all persons except those to whom it was made effective immediately by airmail letter dated March 7, 1975.