EASA AD No : 2012-0057

EASA Form 110 Page 1/4

EASA AIRWORTHINESS DIRECTIVE

AD No.: 2012-0057

Date: 03 April 2012

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European 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, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate 

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].

Type Approval Holder’s Name :

ROLLS-ROYCE PLC

Type/Model designation(s) :

RB211 Trent 900 engines

TCDS Number: EASA.E.012

Foreign AD: Not applicable

Supersedure: This AD supersedes EASA AD 2010-0008R1 dated 04 August 2010.

ATA 72 Engine – Intermediate Pressure Shaft Coupling – Inspection / 

Replacement

Manufacturer(s): Rolls-Royce plc

Applicability: RB211 Trent 970-84, 970B-84, 972-84, 972B-84, 977-84, 977B-84 and

980-84 engines, all serial numbers.

These engines are known to be installed on, but not limited to, Airbus A380

aeroplanes.

Reason: Wear, beyond Engine Manual limits, has been identified on the abutment 

faces of the splines on the Trent 900 Intermediate Pressure (IP) shaft rigid 

coupling on several engines during strip. The shaft to coupling spline interface 

provides the means of controlling the turbine axial setting and wear through of 

the splines would permit the IP turbine to move rearwards.

Rearward movement of the IP turbine would enable contact with static turbine 

components and would result in loss of engine performance with potential for 

in-flight shut down, oil migration and oil fire below the LP turbine discs prior to 

sufficient indication resulting in loss of LP turbine disc integrity. Some of these 

conditions present a potential unsafe condition to the aeroplane.

EASA issued AD 2010-0008R1 to require inspection of the IP shaft coupling 

splines and, depending on the results, further repetitive inspections or 

corrective actions.

Since issuance of that AD, it has been found that when an engine is removed 

from one aeroplane engine position and is re-installed in a different aeroplane

and/or engine position, it may exhibit a change in wear rate. It has therefore 

been found necessary to introduce specific inspection requirements to 

address these cases.
EASA AD No : 2012-0057

EASA Form 110 Page 2/4

Rolls-Royce (RR) have also introduced a modification to the design of the IP 

shaft coupling through Service Bulletin (SB) RB211-72-G585 in order to 

reduce the spline wear rate to an acceptable level. This modification is 

intended to constitute eventually the terminating action for this AD.

However, until service experience has confirmed its efficacy, it has been 

deemed necessary to also require repetitive inspections of engines that have 

been modified in accordance with RR SB 72-G585, but with extended

intervals compared with those for engines not incorporating that modification. 

The inspection technique for engines incorporating the modification differs 

from that for engines not incorporating the modification.

For the reasons described above, this AD retains the requirements of EASA

AD 2010-0008R1, which is superseded, and adds post-SB 72-G585 repetitive 

inspections.

Effective Date: 17 April 2012

Required Action(s) 

and Compliance 

Time(s):

Required as indicated, unless already accomplished:

(1) For engines not incorporating modification SB 72-G585:

 On-wing - Within the applicable compliance times indicated in 

Appendix 1 of this AD, accomplish the actions specified in that 

Appendix, as applicable, in accordance with the instructions of 

sections 1.D(1)(a) and 3.A of RR RB211-Trent 900 Alert Non 

Modification Service Bulletin (NMSB) 72-AG329 Revision 4.

 Each time the engine is inducted into an engine shop (In-shop),

accomplish the actions specified in sections 1.D(1)(b) and 3.B of RR

RB211-Trent 900 NMSB 72-AG329 Revision 4.

(2) For engines incorporating modification SB 72-G585:

 On-wing - Within the applicable compliance times indicated in 

Appendix 1 of this AD, accomplish the actions specified in that 

Appendix, as applicable, in accordance with the instructions of 

sections 1.D(1) and 3.A of RR RB211-Trent 900 Alert NMSB 72-

AG871 Initial Issue.

 Each time the engine is inducted into an engine shop (In-shop),

accomplish the actions specified in sections 1.D(2) and 3.B of RR 

RB211-Trent 900 Alert NMSB 72-AG871 Initial Issue.

(3) For an engine where a new IP shaft coupling (pre- or post-SB 72-G585 

standard) has been installed during an in-shop inspection, or the IP shaft 

coupling has passed the In-shop inspection, as required by paragraph 

(1) or (2) of this AD, except those as specified in paragraph (4) of this 

AD, within 400 flight cycles (FC) after this last In-shop inspection, 

accomplish on-wing inspections as required by paragraph (1) or (2) of 

this AD, as applicable.

(4) For an engine where the pre-SB 72-G585 standard IP shaft coupling has 

passed the borescope inspection in accordance with the instructions of 

NMSB 72-AG329 Rev 4, accomplish the next on-wing inspection, as 

required by paragraph (1) of this AD, within the time specified in 

NMSB72-AG329 Rev 4 Fig 10, and thereafter as specified in Appendix 1 

of this AD.

(5) If, during any inspection as required by this AD, discrepancies are found,

exceeding the criteria, as specified in RR RB211-Trent 900 NMSB 72-

AG329 Revision 4 or RR RB211-Trent 900 Alert NMSB 72-AG871 Initial 

Issue, as applicable, that would allow an IP shaft coupling to remain in 

service or return to service, before next flight (on wing inspection), or 

before release to service of the engine (in-shop inspection), as 

applicable, replace the affected IP shaft coupling with a serviceable part.
EASA AD No : 2012-0057

EASA Form 110 Page 3/4

(6) Inspections and corrective actions, accomplished prior to the effective 

date of this AD, in accordance with the instructions of RR NMSB 72-

AG329 original issue, Revision 1, Revision 2 or Revision 3, are 

acceptable to comply with the requirements of paragraph (1) of this AD. 

After the effective date of this AD, repetitive inspections and corrective 

actions must be accomplished in accordance with the instructions of RR 

NMSB 72-AG329 Revision 4 and RR NMSB 72-AG871 Initial Issue.

(7) Replacement of an IP shaft coupling as required by paragraph (4) of this 

AD, or replacement of an engine with a serviceable engine, does not 

constitute terminating action for the repetitive inspections required by this 

AD.

Ref. Publications: RR RB211-Trent 900 NMSB 72-AG329 Revision 4, dated 23 March 2012.

RR RB211-Trent 900 NMSB 72-AG871 Initial Issue, dated 23 March 2012.

The use of later approved revisions of these documents is acceptable for 

compliance with the requirement of this AD.

Remarks : 1. If requested and appropriately substantiated, EASA can approve

Alternative Methods of Compliance for this AD.

2. The required actions and the risk allowance have granted the issuance 

of a Final AD with Request for Comments, postponing the public 

consultation process after publication.

3. Enquiries regarding this AD 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 your designated Rolls-Royce representative, or 

download the publication from your Aeromanager account at 

www.aeromanager.com.

If you do not have a designated representative or Aeromanager account, 

please contact Corporate Communications at Rolls-Royce plc,

P.O. Box 31, Derby, DE24 8BJ, The United Kingdom.

Telephone: +44 (0) 1332 242424, or e-mail from http://www.rollsroyce.com/contact/civil_team.jsp identifying the correspondence as 

being related to Airworthiness Directives.
EASA AD No : 2012-0057

EASA Form 110 Page 4/4

Appendix 1 - On-wing Borescope Inspection – Initial and Repetitive Inspection

Configuration Condition Action

Compliance Time 

for Initial 

Inspection

Compliance Time 

for Repetitive

Inspections

Engines not

incorporating 

modification

per SB 72-

G585

Engines where the 

coupling life is 250 

FC or less

(see Note 1)

Inspect the IP shaft 

coupling splines –

measurement of 

spline crest – in 

accordance with 

section 3.A of RollsRoyce NMSB 72-

AG329 revision 4

Before the engine 

has accumulated 

400 FC since new

As specified in 

section 1.D(1)(a) 

and 3.A and 

Figure 9 and 10 of

Rolls-Royce 

NMSB 72-AG329 

Revision 4

Engines where the 

coupling life is 

more than 250 FC

(see Note 1)

Within 150 flight 

cycles after 18 

August 2010 [the 

effective date of 

AD 2010-0008R1]

Engines

incorporating 

modification 

per SB 72-

G585

All

Inspect the IP shaft 

coupling spline wear 

(see Note 2) in 

accordance with 

section 3.A of RollsRoyce NMSB 72-

AG871 Initial Issue

Before the engine 

has accumulated 

400 FC since new

As specified in 

section 1.D(1)(b) 

and 3.A of RollsRoyce NMSB 72-

AG871 Initial 

Issue

Note 1: Coupling life is the time since new, or since last inspection of the coupling in accordance with 

the Cleaning, Inspection and Repair Manual. If the coupling life cannot be determined, the life since last 

shop visit should be used to establish the inspection threshold.

Note 2: Due to the differences in design of IP shaft coupling, the inspection of coupling spline wear for 

engines modified with SB 72-G585 consists in measuring distance from the end face of the IP turbine 

seal segment to the front seal fin of the IP turbine blades.