AD 80-04-02

80-04-02 PRATT & WHITNEY AIRCRAFT OF CANADA, LTD.: Amendment 39-3693. Applies to Pratt & Whitney Aircraft of Canada, Ltd. (P&WACL) PT6A-6A, -6B, -6/C20 and -20 turboprop engines. Compliance required within the next 10 hours in service after the effective date of this AD unless already accomplished and every time the propeller reversing interconnect linkage is disconnected. To insure adequate engagement of push-pull control terminal P/N 3010175 into the clevis P/N 3010622 or 3012419, inspect for a maximum of three threads outside the locknut. If more than three threads are visible, re- rig the linkage in accordance with P&WACL Maintenance Manual, P/N 3015422 Part 3, Paragraph 91 and the appropriate aircraft maintenance manual or equivalent inspection or procedure. For clevises incorporating witness holes, a safety wire inserted through one hole should not be able to exit through the opposite hole. Where the safety wire passes through both holes, re-rig in accordance withP&WACL Maintenance Manual, P/N 3015422 Part 3, Paragraph 91 and the appropriate aircraft maintenance manual or equivalent inspection or procedure. Aircraft may be flown to a base for performance of maintenance required by this AD per FAR 21.197 or FAR 21.199. All equivalent inspections and procedures must be approved by the Chief, Engineering & Manufacturing Branch of the Eastern Region of the FAA. (DeHavilland Service Bulletin Nos. A6/387 and ATB/50 pertain to this subject.) This amendment is effective February 8, 1980.