Document ID: chunk:federal_register_of_legislation:F2006B09268:body:0:p2
Version: federal_register_of_legislation:F2006B09268
Segment Type: other
Provision Reference: 
Character Range: 3058–4237

the issue of Amdt. 4 has indicated the airworthiness of tapered crankshafts in service can be satisfactorily determined by two consecutive, insitu, ultrasonic inspections. In response, this amendment limits the insitu ultrasonic inspection requirement to two consecutive inspections.

           In addition to the amended ultrasonic inspection compliance requirement, this amendment also includes a requirement to carry out an ultrasonic inspection of pre Mod G2495 crankshafts before installing that crankshaft in an engine. A Pre Mod G2495 crankshaft, recently inspected insitu by the ultrasonic inspection technique, was reported to be cracked in the area of the thrust bearing location nut threads. On removal of the crankshaft from the engine, and despite knowledge of the crack location, the crack could not be confirmed by MPI. An independent ultrasonic inspection confirmed the presence of a 6mm long by 3mm deep crack.

           Amendment 4 of this Airworthiness Directive became effective on 22 July 1993. Amendment 3 of this Airworthiness Directive became effective on 30 May 1993. The original issue of this Airworthiness Directive became effective in August 1963.