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## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2007-0202 [Corrected: 08 August 2007]

Date: 01 August 2007

No person may operate an aircraft to which an Airworthi ness Directive applies, except in accordance with the requirements of that Airworthiness Directive unless otherwi se agreed with the Authority of the State of Registry. 

### Type Approval Holder’s Name: ROLLS-ROYCE plc 

### Type/Model designation(s):
RB211 Trent 768-60, 772- 60, 772B-60 and 772C-60

TCDS No: EASA E.042

Foreign AD number: Not applicable

Supersedure: Not applicable



### ATA 72 Engine – HP/IP Turbine Bearing Oil Vent Tube Restrictor – Inspection / Cleaning / Replacement

Manufacturer(s): Rolls-Royce plc

Applicability: Models RB211 Trent 768-60 , 772-60, 772B-60 and 772C-60 engines inspected or modified prior to issue of this AD in accordance with: (a) IOR 72-E965 and not subsequently inspected in accordance with NMSB 72-AE302 rev 4 or 5; (b) NMSB 72-AE792 rev 2 or earlier issue and not subsequently inspected in accordance with NMSB 72-AE302 rev 4 or 5; (c) NMSB 72-AE302 rev 3 or earlier issue and not subsequently inspected in accordance with NMSB 72-AE792 rev 3. These engines are known to be installed on Airbus A330 series aeroplanes.

Reason: In October 2003 an uncontained multiple Intermediate Pressure (IP) turbine blade release occurred on an RB211 Trent 700 series engine. The blade release was the result of an overspeed of the IP turbine rotor that was initiated by an internal fire in the HP/IP bearing chamber. Post incident analysis established that blockage of the HP/IP tu rbine bearing oil vent tube, due to oil coking, is a significant factor in the failure sequence. Further analysis has now identified t hat intervention actions that were introduced to address this problem may have increased the rate of carbon formation in the vent pipe. These inte rvention actions are believed to loosen carbon fragments which are subsequently released. This AD has been re-published to indicate that accomplishment of the actions in accordance with the original issue of Rolls-Royce Alert Non Modification Service Bulletin RB211-72-AF424 is an acceptable method of compliance.

Effective Date: 15 August 2007

### 2/2 Compliance/Action: VENT FLOW RESTRICTOR INSPECTION

A. 05 modules of engines in group (a) of the Applicability section (above), carry out the Action (part C. below) within 2 months of the Effective Date of this Airworthiness Directive.

B. 05 modules of engines in group (b) and (c) of the Applicability section (above), carry out the Action (part C. belo w) within 6 months of the Effective Date of this Airworthiness Directive.

C. Action:

Inspect and clean or reject (as necessary) the HP/IP turbine bearing external (IPC ref 79-22-49-10-500) oil vent tube in accordance with Section 3 Accomplishment Instructions of Rolls- Royce Alert Non Modification Service Bulletin RB211-72-AF424 at original issue, or Revision 1 or later approved revisions.

Note: Vent flow restrictor inspection inst ructions, equivalent to those of NMSB 72-AF424 rev 1, were added to NMSB 72-AE302 and NMSB 72-AE792 at rev 4 and rev 3 respectively. Compliance with these NMSBs therefore constitutes satisfactory compliance to this Airworthi ness Directive (this is reflected in the Applicability section of this Airworthiness Directive).

Ref. Publications: Rolls-Royce Alert Non Mod Serv ice Bulletin RB211-72-AF424 original issue or Revision 1; Rolls-Royce Alert Non Mod Service Bulletin RB211-72-AE302 Revision 4; Rolls-Royce Alert Non Mod Service Bulletin RB211-72-AE792 Revision 3; or later approved revisions of these documents.

Remarks: 1. If requested a nd appropriately substant iated the responsible EASA manager for the related product has the authority to accept Alternative Method of Compliance (AMOC) for this AD. 2. This AD was posted on 15 June 2007 as PAD 07-100 for consultation until 28 June 2007. The Comment Response Document can be found at http://ad.easa.europa.eu 3. Enquiries regarding this AD should be referred to the AD Focal Point - Certification Directorate, EASA. E-mail: ADs@easa.europa.eu 4. For any questions concerning the tech nical content of the requirements in this AD, please contact Rolls-Royce plc. PO Box 31, Derby, DE24 8BJ, United Kingdom. Phone: +44 (0) 1332 242424, Fax: +44 (0) 1332 249936.