AD 69-25-04

69-25-04 FAIRCHILD-HILLER: Amdt. 39-886. Applies to Fairchild Hiller F-27 and FH-227 type Airplanes, except FH-227D and FH-227E, certificated in all categories.

To prevent the hazards associated with the flaps driving off the ends of the screw jacks due to a single failure of the drive system which actuates the normal flap control limit switches and the emergency power cutoff switches, accomplish the following:

(a) Within the next 100 hours' in service after the effective date of this airworthiness directive, unless already accomplished within the last 25 hours in service, and thereafter at intervals not to exceed 125 hours' in service, until incorporation of the modification noted in (b).

(1) Inspect the universal joint at each end of the wing flap connecting shaft assembly P/N 27-727994-11 located between the flap motor gearbox at wing station 141 left (installed in the wheel well of the left nacelle) and the gearbox at wing station 121 left, to assure some freedom of movement in all axes.

(2) Inspect the universal joint of the actuator shaft P/N 27-727920-7, -9, or -13, as applicable, also located on the gearbox at wing station 121 left, noted in (a)(1) above, to assure some freedom of movement in all axes.

(3) If freedom of movement is not determinable, remove and replace deficient universal joint pin or bolt before further flight.

(4) Lubricate the three universal joints, noted in (a)(1) and (a)(2) above, in accordance with applicable maintenance manual instructions.

(b) Within the next 1000 hours' in service after the effective date of this airworthiness directive, unless already accomplished, separate the existing flap "up and down" limit switches from the emergency flap power cutoff switches by complying with Fairchild Hiller Service Bulletin F-27-27-64, Revision 3, dated 1 October 1969, for F-27 type airplanes with pre-select flap control, and Fairchild Hiller Service Bulletin FH-227-27-22, Revision 1, dated 2April 1969 for FH-227 type airplanes, or later revisions thereto, or equivalent modification both approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

(c) Upon request with substantiation data submitted through an FAA maintenance inspector, compliance time may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

This amendment is effective December 6, 1969.