EASA AD No.: 20 12

- 0 120

CAP.0011 0

- 001 © Europe an Aviation Safety Agency. All rights reserved. 1 / 2 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No

. : 20 12

- 0 120

Date: 04 Ju ly 2012

Note: This Airworthiness Directive ( AD) is issued by EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the Europe an Community, its Member States and of the European third countries that participate in the activities of EASA under Article 66 of that Regulation.
This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, th e continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may ope rate an aircraft to which an AD applies, except in accordance with the requirements of that AD, unless otherwise specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption]

. 

### Design Approval Holder’s Name :

Rolls

- Royce plc Type/Model designation(s) :

RB211 Trent 800 Engines

TCDS Number : U nited K ingdom No. 10 51

F oreign AD: N ot applicable

Supersedure: N one



### ATA 73 Engine

– Interme diate Pressure (IP) Turbine Disc

– Identification / Inspection / Re placement

Manufacturer(s): Rolls

- Royce plc

Applicability: RB211 Trent 875

- 17, 877

- 17, 884

- 17, 884B

- 17, 892

- 17, 892B

- 17 and 895

- 17 engines, all serial numbers. These engines are known to be installed on, but not limited to, Boeing 777 series aeroplanes.

Reason: The inspection of several IP t urbine d iscs at past en gine overhauls identified the presence of steel inclusions in these parts. Further investigation concluded that all affected p arts were manufactured from Waspalloy billets produced before 1997 at a certain supplier who also melted steel in the same furnaces. Initial engineering evaluation concluded that the lives of the parts would not be affected by the presence of the said stee l inclusions. This evaluation has been recently repeated

, utilising improved structural analysis

, and it is now concluded that the currently published lives of the components cannot be supported for some discs with a steel inclusion. This condition, if not corrected, could l e ad to an uncontained IP t urbine d isc failure , possibly resulting in damage to, and reduced control of, the aeroplane

. For the reasons described above

, this AD requ ires replacement of certain IP t urbine d iscs

. This AD also prohibits ( re ) installation of certain IP turbine discs on an engine.

Effective Date: 1 8 July 2012EASA AD No.: 20 12

- 0 120

CAP.0011 0

- 001 © Europe an Aviation Safety Agency. All rights reserved. 2 / 2 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. Required A ction(s) and Compliance Time(s) : Required as indicated, unless accomplished previously: (1) D uring the next engine shop visit aft er the effective date of this AD where the Module 05 i s removed from the engine or, i n case that, on the effective date of this AD, an engine happens to be in such a shop visit, inspect the IP turbine disc installed on the engine to identify the serial num ber (s/n)

. (2) I f , during the inspe ction as required by paragraph (1) of this AD, it is identified that a turbine disc is installed with a s / n as listed in Table 1 of this AD

, accomplish one of the following a ction s , as applicable, in accordance with the instructions of Rolls

- Royce RB211 Trent 800 Series Propulsion Systems Non

- Modification Service Bulletin (NMSB) RB211

- 72

- AG 795 ( h e r e a f t e r r e f e r r e d t o a s t h e N M S B ) : (2. 1) If the IP turbine disc accumulated life e xceeds 9 700 engine cycles

, before returning the engine to service, r e place the IP t urbine d isc with a serviceable part

, in accordance with the instructions of the NMS B

. (2.2) If the accumulated life of the IP turbine disc is below the 9 700 engine cycles t hreshold

, before the IP turbine disc exceeds tha t threshold,

re place the IP turbine disc with a serviceable part

, in accordance with the instructions of the NMS B

.

Table 1

– Affected IP Turbine Discs

IP turbine disc s / n
ADREB 73 ADREB 85 ADREB 92
ADREB 79 ADREB 86 ADREB 94

ADREB 80 ADREB 87 ADREB 96
ADREB 81 ADREB 88 ADREB 102
ADREB 82 ADREB 89 ADREB 103

ADREB 83 ADREB 90 ADREB 104
ADREB 84 ADREB 91

( 3 ) From the effective date of this AD, do not install on any engine an IP turbine disc with a s / n as listed in Table 1 of this AD

, except in accordance with the requir ements of this AD.

Ref. Public ations: Rolls

- Royce RB211 Trent 800 Series Propulsion Systems NMSB RB211

- 72

- AG 795

, dated 28 October 2011. The use of later approved revisions of th i s document is acceptable for compliance with the requirements of this AD.

Re marks : 1. If requested and appropriately substantiated, EASA can approve Alternative Methods of Compliance for this AD.

2. This AD was posted on 0 4 June 2012 as PAD 1 2

- 0 58 for consultation until 0 2 Jul y 201 2

. No comments were received during the consultation period

. 3. Enquiries regarding this A D should be referred to the Safety Information Section

, Executive Directorate, EASA. E

- mail ADs@easa.europa.eu

4. For any question concerning the technical content of the requirements in this AD, please contact y our designated Rolls

- Royce representative, or download the publication from your Aeromanager account at www.aeromanager.com , or contact at Rolls

- Royce plc. Corporate Communications, P.O. Box 31, Derby, DE24 8BJ, United Kingdom, telephone: +44 (0) 1332 242424, or send an e

- mail through http://www.rolls

royce.com/contact/civil_team.jsp identifying the correspondence as being related to Airworthiness Directives

.