Document ID: chunk:federal_register_of_legislation:F2008L00388:body:0:p2
Version: federal_register_of_legislation:F2008L00388
Segment Type: other
Provision Reference: 
Character Range: 3181–3993

Before installing the engine on an aircraft.
             This Airworthiness Directive becomes effective on 13 March 2008.
Background:  Several low pressure turbine (LPT) shafts have been found with cracks originating from the rear cooling air holes.  The cracks were found at normal component overhaul, by the standard Magnetic Particle Inspection (MPI) technique defined in the associated engine manual.  The cracks have been found to initiate from corrosion pits. Propagation of a crack from the rear cooling air holes may result in shaft failure and subsequently in an uncontained Low Pressure Turbine failure.  This AD requires the inspection of the affected engines' LPT shafts and replacement of the shaft, as necessary.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

21 January 2008