Document ID: chunk:federal_register_of_legislation:F2008L00881:body:0:p2
Version: federal_register_of_legislation:F2008L00881
Segment Type: other
Provision Reference: 
Character Range: 3044–4256

later.
                This Airworthiness Directive becomes effective on 10 April 2008.
Background:     PW206 and PW207 Compressor Turbine (CT) Disk bore areas may experience impact damage resulting from bending or fracture of the CT Disk Retaining Nut castellations.  Damage of the CT disk bore area can reduce LCF capabilities of the CT disk, resulting in disk fracture.

                To preclude any potentially hazardous situation precipitated by a damaged CT disc, P&WC issued Alert Service bulletin PW200-72-A28280, requiring inspection of the CT disc bore area for damage and replacement of the existing Disk Retaining Nut with an improved design nut.

                The most recent compliance data indicates that the majority of the affected engines, particularly those with high in-service time, still have not been inspected to SB PW200-72-A28280 requirements and as such, are potentially susceptible to CT disc damage.  This AD is issued to mandate the inspection of the CT disc bore area and replacement of the existing Disk Retaining Nut, in accordance with SB
                PW200-72-A28280 R4 instructions.

David Punshon
Delegate of the Civil Aviation Safety Authority

26 February 2008