Ad/AE 3007/6 - High Pressure Turbine Stage 2 Wheels (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 (Allison) Turbine Engines - AE 3007 Series

AD/AE 3007/6 High Pressure Turbine Stage 2 Wheels 11/2008 TX

Applicability:

Rolls-Royce Corporation (RRC) (Formerly Allison Engine Company): AE 3007A series turbofan engines.

Note 1:  These engines are installed on, but not limited to Empresa Brasileira de Aeronautica S. A. (EMBRAER) EMB-135 and EMB-145 aeroplanes.

Requirement:

1.    Do not install any RRC AE 3007A series engine that has an high pressure turbine (HPT) stage 2 wheel with 6,500 or more cycles-since-new (CSN) on any aeroplane unless the HPT stage 2 wheel was inspected as specified in RRC Alert Service Bulletin (ASB) AE 3007A-A-72-367, dated 5 September 2008.

2.    Perform an eddy current inspection (ECI) on the HPT stage 2 wheel using paragraphs 2.A. through 2.C.(4) of RRC ASB AE 3007A-A-72-367.

Later revisions of the above ASB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-19-51 are considered acceptable for compliance with the equivalent Requirements of this Directive.

Note 2:  FAA Emergency AD 2008-19-51 dated 8 September 2008 refers.

Compliance:

For Requirement 1 - From the effective date of this AD.

For Requirement 2 - As detailed in Table 1 of this AD for the initial inspection and thereafter at intervals not to exceed 2,500 cycles since-last inspection.

Table 1 - Compliance Times for ECI of the HPT Stage 2 Wheels

For HPT stage 2 wheels with	Perform ECI within
(1)   19,000 or more CSN on the effective date of this AD.	120 cycles-in-service (CIS) or the next time the engine is at any maintenance facility for a type of maintenance after the effective date of this AD, whichever occurs first.
(2)   18,000 to 18,999 CSN on the effective date of this AD.	400 CIS or the next time the engine is at a maintenance facility for any type of maintenance after the effective date of this AD, whichever occurs first.
(3)   16,000 to 17,999 CSN on the effective date of this AD.	600 CIS or the next time the engine is at a maintenance facility for any type of maintenance after the effective date of this AD, whichever occurs first.
(4)   12,000 to 15,999 CSN on the effective date of this AD.	1,000 CIS or the next time the engine is at a maintenance facility for any type of maintenance after the effective date of this AD, whichever occurs first.
(5)   6,500 to 11,999 CSN on the effective date of this AD.	2,000 CIS or the next time the engine is at a maintenance facility for any type of maintenance after the effective date of this AD, whichever occurs first.
(6)   Fewer than 6,500 CSN on the effective date of this AD.	The next time the engine is at a maintenance facility for any type of maintenance after accumulating 6,500 CSN, but not to exceed 11,999 CSN.

For the purposes of this AD “maintenance facility” means when an engine is removed and sent to an engine maintenance facility that can perform the inspection detailed in this AD.

This Airworthiness Directive becomes effective on 12 September 2008.

Background: This AD results from reports of cracked high-pressure turbine stage 2 wheels.  This condition, if not corrected, could result in a possible uncontained failure of the high pressure turbine stage 2 wheel, which could cause damage to the aeroplane.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

10 September 2008