79-12-09 PIPER AIRCRAFT CORP: Amendment 39-3494. Applies to Model PA-36-285 serial numbers 36-7360001 through 36-7660135 airplanes certificated in all categories. To detect cracks in the engine mount attachment brackets, accomplish the following:
(a) Within the next 50 hours in service from the effective date of this AD, unless accomplished within the previous 50 hours in service, and at intervals thereafter not to exceed 100 hours in service from the last inspection, inspect welds for cracks on the aft side of the gussets on the fuselage where the engine mount is attached using dye check or fluorescent penetrant inspection procedures or equivalent.
(b) If cracks are found, install Piper Engine Mount Attachment Modification Kit No. 763877, or equivalent, prior to further flight. During the installation of the kit, inspect the welds for cracks on the forward side of the gussets on the fuselage where the engine mount is attached using dye check or fluorescent penetrantinspection procedures or equivalent. If cracks are found, remove weld from cracked area and reweld.
(c) Upon incorporation of Piper Modification Kit No. 763877 or equivalent, compliance with this AD may be cancelled.
(d) Equivalent inspections and repairs must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.
(e) Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region may adjust the inspection intervals specified in this AD.
Piper S/B No. 615 dated 9/21/78, pertains to this subject.
This amendment is effective June 19, 1979.