# AIRWORTHINESS DIRECTIVE 

# United Kingdom Civil Aviation Authority AD No: G-2006-0002

Issue Date: 13 February 2006

This AD is issued by the UK CAA acting for and on behalf of the European Aviation Safety Agency as the Primary Aviation Authori ty (ICA O Annex 8 Authority of State of Design) for the affected product(s).

A pprov ed by the European A v iation Safety A g ency under approv al number 2006-0034 on 25 January 2006.

In accordance w i th Article 10 of the Air Navigation Order 2005 as amended the follow i ng action requi red by this Airw orthiness D irective (AD) i s mandatory for applicable aircraft registered in the United Kingdom. No person may operate an aircraft to w h ich an AD applies except in accordance w i th the requirements of that AD unless otherw i se agreed

w i th the Authority of the State of Registry

. 

### Type Approval Holders Name:

ROLLS-ROYCE PLC 

### Type/Model Designation(s):

RB211-524

Ty pe Certificate Data Sheet No: 1043, 1046, 1048

CORRECTION to G-2006-0002 dated 31 January 2006

ATA 72 – ENGINE TURBINE SECTION – HIGH PRESSURE TURBINE – INSPECTION

Manufacturer(s): Rolls-Royce plc

Applicability : Model RB211-524 series engines, all marks, installed on Boeing 747 & 767 and Lockheed L1011 aeroplanes fitted with the following HP turbine discs only:

This directive is not applicable to HP turbine discs, which are pre-modification SB72-7730, post-modification SB72-C109 or post-modification SB72-C762. Part No F K 24651: Serial No LAQDY6061 (single disc) Part No FK24651: Serial No LDRCZ10453 to Serial No LDRCZ10720 (inclusive) Part No F K 24651: Serial No LQDY9903 (single disc) Part No F K 24651: Serial No LQDY9924 (single disc) Part No FK24790: Serial No CRCZ6 to CRCZ25 (inclusive) Part No FK24790: Serial No LDRCZ10717 to LDRCZ14022 (inclusive) Part No UL23166: Serial No LQDY6516 to LQDY8718 (inclusive) Part No UL24561: Serial No LQDY6389 to LQDY6438 (inclusive) Part No UL24994: Serial No LQDY6405 to LQDY8727 (inclusive) Part No UL29472: Serial No LAQDY6013 to LAQDY6092 (inclusive) Part No UL29472: Serial No LDRCZ10029 to LDRCZ10821 (inclusive) Part No UL29472: Serial No LDRCZ6000 to LDRCZ6060 (inclusive) Part No UL29472: Serial No LQDY6592 to LQDY9993 (inclusive) Part No UL29473: Serial No CRCZ24 to CRCZ25 (inclusive) Part No UL29473: Serial No CZ 12135 to CZ 12333 (inclusive) Part No UL29473: Serial No LAQDY6010 to LAQDY6088 (inclusive) Part No UL29473: Serial No LDRCZ10003 to LDRCZ15372 (inclusive) Part No UL29473: Serial No LDRCZ6001 to LDRCZ9995 (inclusive) Part No UL29473: Serial No LQDY10001 (single disc) Part No UL29473: Serial No LQDY9606 to LQDY9989 (inclusive)



### Effectiv e Date: 15 February 2006 continued on next page

### G-2006-0002 page 2 of 3

Reason: A population of HP turbine discs that were m anufactured between 1989-1999 and which were subject to possible machining anomalies, were believed to hav e an increased chance of suffering from cooling air hole cracking, compared to the general fleet population of HP turbine discs. As a result of this risk, Rolls-Royce issued Non-Modification Service Bulletin (NMSB) 72-C816, recommending in-service inspections of the subject discs.

Recently an RB211 HP turbine disc has been found with a crack which had propagated further than expected from the risk model that was used to establish the orig inal inspection defined in the above NMSB; This has led to the need for a revision of the original inspection requirements.

An HP turbine disc fracture would be uncontained and creat e a potential unsafe condition. Accordingly, this AD introduces revised inspection requirements to reflect t he increased risk of HP turbine disc cracking and potential disc fracture.

Compliance/Action: Carry out the eddy current inspection as detailed in Section 3 - Accomplishment Instructions of Rolls-Royce NMSB 72-AE718 original i ssue or later EASA approved revision in accordance with the following schedule:

1. The HP disc serial numbers listed in Table 1 are to be inspected as follows:

continued on next page Table 1 Part No Serial No Part No Serial No UL29473 LAQDY6043 UL29472 LQDY9125 UL29473 LAQDY6048 UL29472 LQDY9554 UL29473 LAQDY6079 UL29472 LQDY9582 UL29473 LDRCZ10057 UL29472 LQDY9895 UL29473 LDRCZ10264 UL29472 LQDY9910 UL29473 LDRCZ10415 UL29472 LQDY9947 UL29473 LDRCZ11402 UL29472 LQDY9960 UL29473 LDRCZ11425 UL24994 LQDY6777 UL29473 LDRCZ11497 UL24994 LQDY6792 UL29473 LDRCZ11663 UL24994 LQDY6859 UL29473 LDRCZ11679 UL24994 LQDY6860 UL29473 LDRCZ12301 UL24994 LQDY6866 UL29473 LDRCZ12308 UL24994 LQDY6869 UL29473 LDRCZ12316 UL24994 LQDY6934 UL29473 LDRCZ12319 UL24994 LQDY6946 UL29473 LQDY6957 UL24994 LQDY6963 UL29473 LQDY9075 UL23166 LQDY6745 UL29473 LQDY9084 UL23166 LQDY6846 UL29473 LQDY9557 UL23166 LQDY6848 UL29473 LQDY9906 UL23166 LQDY6954 UL29473 LQDY9956 FK24790 LDRCZ12492 UL29473 LQDY9970 FK24790 LDRCZ12694 UL29473 LQDY9985

### G-2006-0002 page 3 of 3

A. For all RB211-524 engine marks except RB211-524D4 variants

(a) If the HP turbine disc cycles were greater than 6150 cycles since new on 24 November 2005, inspect the HP turbine disc within 500 cycles from 24 November 2005.

(b) If the HP turbine disc cycles were less than 6150 cycles since new on 24 November 2005, inspect the disc by whichever is the soonest of the conditions below:

i. Prior to reaching 6650 cycles since new. The HP turbine disc life at inspection must be greater than 700 cycles since new.

ii. At next shop visit where the HP turbine roto r is removed from the Combustor Outer Case and the HP turbine disc life is great er than 700 cycles since new. If a HP turbine disc that meets these cyclic life criteria is curr ently at shop visit, and if, at the e ffective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the r equirements of this Airw orthiness Directive at the current shop visit.

B. For all RB211-524D4 engine mark variants

(a) If the HP turbine disc cycles were greater than 5000 cycles since new on 24 November 2005, inspect the HP turbine disc within 500 cycles from 24 November 2005.

(b) If the HP turbine disc cycles were less than 5000 cycles since new on 24 November 2005, inspect the HP turbine disc by whichever is the soonest of the conditions below:

i. Prior to reaching 5500 cycles since new. The HP turbine disc life at inspection must be greater than 700 cycles since new.

At the next shop visit where the HP turbine rotor is removed from the Combustor Outer Case and the HP turbine disc life is greater than 700 cycles since new. If a HP turbine disc that meets thes e cyclic life criteria is currently at shop visit, and if, at the effective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the requirements of this Airworthine ss Directive at the current shop visit.

2. For all other HP turbine discs specified in the Applicab ility of this Directive but not listed in Table 1 on page 2.

Inspect the HP turbine disc at next shop visit where t he HP turbine rotor is removed from the Combustor Outer Case and the HP turbine disc life is greater than 700 cycles since new. If a HP turbine disc that meets these cyclic life criteria is currently at shop visit, and if, at the effective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the requirements of this Airw orthiness Directive at the current shop visit.

3. If a HP turbine disc has previously passed the in spection to Rolls-Royce NMSB 72-C816 or the focussed inspection carried out in accordance with Rolls-Royce TS594-J Overhaul Process Manual Task 70-00-00- 200-223 at greater than 700 cycles since new, then either of these inspections meets the requirements of this Airworthiness Directive.

Reference Publications: Rolls-Royce Service Bulletins may be obt ained from Rolls-Royce plc, Technical Publications, PO Box 31, Derby, DE24 8BJ, United Kingdom. Phone +44 (0) 1332 242424 Fax +44 (0) 1332 249936.

Remarks: Enquiries regarding this Airworthiness Directive ma y be directed to Civil Aviation Authority, Safety Regulation Group, Propulsion Department, Aviation House, Gatwick Airport South, West Sussex, RH6 0YR, United Kingdom. Phone: +44 (0) 1293 573641 Fax: +44 (0) 1293 573979 E-mail: propulsion.dept@srg.caa.co.uk.