AD/Tay/15 Amdt 2 High Pressure Turbine Stage 1 Discs (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/TAY/15 Amdt 1 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Rolls Royce Turbine Engines - Tay Series

AD/TAY/15 Amdt 2 High Pressure Turbine Stage 1 Discs 6/2007 DM

Applicability:

All Tay 650-15 and Tay 651-54 engines with High Pressure Turbine Stage 1 Disc Part Number JR 32013 (pre SB TAY-72-1241 standard).

Note 1:  These engines are known to be installed, but not limited to Fokker 100 and Boeing 727 aircraft.

Requirement:

After the 31 August 2005 accomplish the following:

1. For Tay 650-15 engines, with affected High Pressure Turbine Stage 1 Disc, that had been exposed to flight profiles that are different to the currently operated profile, the cyclic life consumption for the High Pressure Turbine Stage 1 Discs must be re-established as defined in Rolls-Royce Deutschland Alert Non-Modification Service Bulletin TAY-72-A1676 R2, dated 23 March 2007.

2. For Tay 650-15 and Tay 651-54 engines replace affected High Pressure Turbine Stage 1 Discs at or before reaching the cyclic life limits as defined in Rolls-Royce Deutschland Alert Non-Modification Service Bulletin TAY-72A-1676 R2.

Note 2:  EASA AD 2007-0086 dated 30 March 2007 refers.  This AD supersedes LBA AD D-2005-252R1.

Compliance:

1.    No later than 30 calendar days after the effective date of this AD.

2.    In accordance with the Rolls-Royce Deutschland Alert Service Bulletin
TAY-72-A1676R2.

This Amendment becomes effective on 30 April 2007.

Background:

This Directive requires replacing certain HPT stage 1 discs at or before reaching a new reduced life cycle limit.  This Directive is prompted by an updated low-cycle-fatigue (LCF) analysis of the HPT stage 1 disc performed by the manufacturer.  This Directive is intended to prevent LCF cracking and failure of the HPT stage 1 disc due to exceeding the life limit, which could result in an uncontained engine failure and damage to the aeroplane.

Amendment 2 reduces the range of the discs affected by this AD.  This AD only applies to High Pressure Turbine Stage 1 Disc Part Number JR 32013 (pre SB
TAY-72-1241 standard).

Amendment 1 of this AD became effective on 27 October 2005.

The original issue of this AD became effective on 29 September 2005.

David Punshon
Delegate of the Civil Aviation Safety Authority

24 April 2007