Summary
This document proposes the supersedure of two existing airworthiness directives (ADs), applicable to International Aero Engines AG (IAE) V2500-A1 series turofan engines, one of which, AD 98- 20-18, currently requires removal from service of affected high pressure turbine (HPT) disks, identified by part number and serial number in the applicability paragraph of that AD, and replacement with a serviceable part. The other current AD, 99-05-05, requires initial and repetitive inspections of certain HPT stage 1 and stage 2 disks utilizing an improved ultrasonic method when the disks are exposed during a normal shop visit, and is a subsurface anomaly is found, removal from service and replacement with a serviceable part. This action would require the initial inspection required by AD 99-05-05 to be completed at the next shop visit regardless of the planned maintenance or the reason for shop removal. The repetitive inspection interval would also be redefined to eliminate the cyclic limit and thus be less restrictive. This proposal is prompted by results from further investigation subsequent to the publication of AD 98-20-18 that have revealed that the HPT disks affected by that AD are part of the population addressed by AD 99-05-05. These HPT disks can be safely reintroduced into service after completing the initial inspection requirements mandated by this proposed AD. This proposal is also prompted by further analysis which indicates a reduction in risk if the initial inspection required by AD 99-05-05 is completed sooner and that the subsequent required inspections can be redefined to eliminate the cyclic limit creating less burden on operators. The actions specified by the proposed AD are intended to prevent HPT disk fracture, which could result in an uncontained engine failure and damage to the airplane.