AD/RB211/39 High Pressure Compressor Rotor Discs and Rotor Shafts (Cth)
AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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 - RB211 Series
| AD/RB211/39 | High Pressure Compressor Rotor Discs and Rotor Shafts | 6/2009 |
Applicability: | Rolls-Royce plc RB211-524G2-T-19, RB211-524G3-T-19, RB211-524H-T-36 and RB211-524H2-T-19 engines, if a High Pressure (HP) Compressor Rotor Shaft, P/N FK25502, FK20195 or FW23711 is installed. Note 1: These engines are known to be installed on, but not limited to, Boeing 747 and Boeing 767 series aeroplanes. |
Requirement: | Carry out the inspections defined in Section 3. Accomplishment Instructions of The use of later approved revisions of this document is acceptable for compliance with the requirements of this AD. Note 2: EASA AD 2009-0073R1 dated 8 April 2009 refers. |
Compliance: | If, on the effective date of this AD, the life of the HP Compressor Stage 1 to 4 Rotor Discs or the HP Compressor Rotor Shafts is equal to or greater than 1,000 Cycles Since New (CSN) and the engine is at Refurbishment (Level 3) shop visit; and If, on the effective date of this AD, the life of the HP Compressor Stage 1 to 4 Rotor Discs or the HP Compressor Rotor Shafts is equal to or greater than 1,000 CSN and the engine is at Overhaul (Level 4) shop visit; and If, on the effective date of this AD, the life of the HP Compressor Stage 1 to 4 Rotor Discs or the HP Compressor Rotor Shafts is equal to or greater than 1,000 CSN and the HP Compressor Rotor is at piece part level; and When the life of the HP Compressor Stage 1 to 4 Rotor Discs or the HP Compressor Rotor Shaft is greater than or equal to 1,000 CSN, at every engine Refurbishment (Level 3) shop visit, every engine Overhaul (Level 4) shop visit and each time the HP Compressor is at piece part level. |
| This Airworthiness Directive becomes effective on 4 June 2009. |
Background: | During manufacture of a number of HP Compressor Stage 1 and 2 discs with axial dovetail slots, anomalies at the disc post corners have been found. Fatigue crack initiation and subsequent crack propagation at the disc post may result in release of two blades and the disc post. This may potentially be beyond the containment capabilities of the engine casings. Thus, these anomalies present at the disc posts constitute a potentially unsafe condition. For the reasons described above, this AD requires repetitive inspections of the axial dovetail slots and follow-on corrective action, depending on findings. |
James Coyne
Delegate of the Civil Aviation Safety Authority
17 April 2009
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