EASA AD No: 2009-0236

EASA Form 110 Page 1/6 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2009-0236

Date: 29 October 2009

Note: This Airworthiness Directive (AD) is i ssued 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 applic able ADs. Consequently, no person may opera te an aircraft to which an Airworthiness Directive applies, except in accordance with the requirements of that Airworthiness Directiv e 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 [E C 216/2008, Article 14(4) exemption].


### Type Approval Holder’s Name :

Turboméca Type/Model designation(s) :

Arriel 1 series turboshaft engines

TCDS Number : EASA.E.073

Foreign AD : Not applicable

Supersedure: This AD supersedes EASA AD 2007-0018R 1, dated 14 August 2007.



### ATA 72 Engine – Gas Generator 2 nd 

### Stage Turbine – Inspection / Replacement

Manufacturer(s): Turboméca

Applicability: All ARRIEL 1B post-mod TU 148, ARRIEL 1D, ARRIEL 1D1 and ARRIEL 1S1 turboshaft engines, not modified with Turboméca modification TU347 [Introduced by Service Bulletin (SB) 292 72 0347 – Installation of turbine Part Number (P/N) 0 292 25 039 0]
These engines are known to be installed on, but not limited to, the following helicopters: Eurocopter AS 350 B/BA/BB/B1/B2 and Sikorsky S-76A+/A++/C.

Reason: Several cases of release of gas generator 2nd stage turbine blade occurred in service, with full containment of debris. These events resulted in an uncommanded In-Flight Shut Down (IFSD) of the engine. While awaiting terminating actions, it was deci ded to implement mandatory check and replacement of the turbine in order to reduce the probab ility of uncommanded engine IFSD. EASA AD 2007-0018 retained the requireme nts of previous DGAC AD F-2004-047 and included changes with r egard to ARRIEL 1B engines only. Reduction of the turbine blade life limit fr om 6 000 hours to 3 000 hours was taken as a precautionary measure fo llowing additional events. EASA AD 2007-0018R1 reduced the original AD applicability following introduction of a new Turbine P/N 0 292 25 039 0 available for all Arriel 1 engine models through Turboméca Modification TU347 or SB 292 72 0347. This new TurbineEASA AD No: 2009-0236

EASA Form 110 Page 2/6 incorporates improvements that are the te rminating action for this AD. Therefore inspections and replacement requirements were deleted for engines equipped with the new Turbine P/N 0 292 25 039 0.

Since the issuance of EASA AD 2007-0018 R1 new cases of release of gas generator 2nd stage turbine blade pre-TU347 have occurred at lower blade service lives compared to previous events.
This AD supersedes AD 2007-0018R1 by lowering some inspection thresholds and repetitive intervals, loweri ng the life limits of the 2 nd stage turbine blades, and lowering replacement thresholds of the 2 nd stage turbine disks and blades preTU347, for single-engine applications. Compared to PAD 09-96, the 2nd stage turbine blade life limit and replacement allowances for turbines that are currently in service have been optimised based on parts availability while keeping the risk level within acceptable limits.

Effective Date: 12 November 2009

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously:

1. Inspections: Once the 2nd stage turbine has accumulated 1 200 Engine Flight Hours (EFH) or 3 500 cycles since new or since inspection in a repair centre:

- Do checks in accordance with the following tables and associated Turboméca Mandatory Service Bulletins (MSBs): Table 1.a: 2nd Stage Turbine Inspection Requirements

and
Table 1.b: Acceptability of che cks performed in accordance with previous and latest MSBs Attention should be paid to engine configurations, conditions, actions, compliance time and repetitive intervals.

2. Life Limits of the 2 nd Stage Turbine Blades: The life limits of the 2nd stage turbine blades must be set to the values provided in:

Table 2: Life Limits of the 2 nd Stage Turbine Blades

3. Replacement of the 2 nd Stage Turbine Disk and Blades: The replacement requirements for the 2nd Stage Turbine Disk and Blades are provided in: Table 3.1: 2nd Stage Turbine Replacement Requirements – Arriel 1B Table 3.2: 2nd Stage Turbine Replacement Requirements – Arriel 1D, 1D1

Notes : - Inspection intervals for Arriel 1S1 engines are unchanged compared to the requirements of AD 2007-0018R1. - Inspection requirements, 2nd stage turbine Blade life limits and turbine replacement requirements do not apply to post TU-347 turbine, which is the terminating action of this AD. - The referenced tables can be found in the Appendix of this AD (page 4 - 6).

Ref. Publications: Turboméca Mandatory Service Bulletins (MSBs)
A292 72 0807 Version E, dated 29 October 2009EASA AD No: 2009-0236

EASA Form 110 Page 3/6 A292 72 0810 Version C, dated 24 July 2009
The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately subs tantiated, EASA can approve Alternative Methods of Compliance for this AD.
2. This AD was posted on 31 July 2009 as PAD 09-096 for consultation until 28 August 2009. No comments were re ceived during the consultation period. 3. Enquiries regarding this AD should be referred to the Airworthiness Directives, Safety Management & Research Section, Certific ation Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any questions concerning the techni cal content of the requirements in this AD, please contact: Turboméca , S.A., ARRIEL 1 Customer Support, 40220 TARNOS, FRANCE. Fax: +33 5 59 74 45 15; or contact your nearest technical representative at www.turbomeca-support.comEASA AD No: 2009-0236

EASA Form 110 Page 4/6

Appendix to AD 2009-0236

Table 1.a: 2nd Stage Turbine Inspection Requirements Once the 2nd stage turbine has accumulated 1 200 EFH or 3 500 cycles since new or since inspection in a repair centre:

Configuration Condition Action Compliance Time Repetitive Interval (Not to Exceed)

If no check has been previously done or if the blades have been in operation for more than 100 EFH since a check according to relevant MSB (1) Within 50 EFH
Arriel 1B, Arriel 1D,
Arriel 1D1 If the blades have been in operation for less than 100 EFH since a check done according to relevant MSB (1) Do a check of the relative position of the 2 nd stage turbine blades, in accordance with MSB A292 72 0807 Version E, Par. 2B(1)(a)&(b) or 2B(2)(a) Within 150 EFH since the last check Every 150 EFH,
until installation of an inspected pre-TU347 turbine fitted with new blades, or a post-TU347 turbine

If no check has been previously done or if the blades have been in operation for more than 100 EFH since a check according to relevant MSB (2) Within 50 EFH

Arriel 1S1

If the blades have been in operation for less than 100 EFH since a check done according to relevant MSB (2) Do a check of the relative position of the 2 nd stage turbine blades, in accordance with MSB A292 72 0810 Version C, Par. 2B(1)(a)&(b) or 2B(2)(a),(b)&(c) Within 150 EFH since the last check Every 150 EFH,
until installation of an inspected pre-TU347 turbine fitted with new blades, or a post-TU347 turbine

Notes:
(1) & (2) : Refer to Table 1.b EFH = Engine Flight Hours

Table 1.b: Acceptability of checks performed in accordance with previous and latest MSBs

Note Variant Previous MSBs Latest MSBs

(1) Arriel 1B MSB A292 72 0263 (Initial Issue to Update 5), or MSB A292 72 0807 (Version A to Version D)

(1) Arriel 1D,
Arriel 1D1 MSB A292 72 0263 (Initial Issue to Update 5), or MSB A292 72 0808 (Initial Issue to Update 1), or MSB A292 72 0809 (Version A to Version D) MSB A292 72 0807 Version E

(2) Arriel 1S1 MSB A292 72 0263 (Initial Issue to Update 5), or MSB A292 72 0810 (Version A to Version B) MSB A292 72 0810 Version CEASA AD No: 2009-0236

EASA Form 110 Page 5/6

Table 2: Life Limits of the 2nd Stage Turbine Blades

Configuration 2 nd Stage Turbine Blade Life Limit
Arriel 1B, Arriel 1D,
Arriel 1D1 1200 hours (except allowances as defined in Table 3)

Table 3.1: 2nd Stage Turbine Replacement Requirements – Arriel 1B

Configuration Condition Action Compliance Time Repetitive Interval (Not to Exceed)
Engines with 2 nd stage turbine blades having accumulated more than 3 000 EFH since new, or 2 nd stage turbine disk having accumulated more than 2 200 EFH since new or inspection
whichever comes first Before next flight Note: Already required by AD 2007-0018R1

Engines with 2 nd stage turbine blades having accumulated more than 1 800 EFH and less than 3 000 EFH since new Within the next 400 EFH, or Before 2 nd stage turbine blades have accumulated 3 000 EFH since new, or Before 2 nd stage turbine disk has accumulated 2 200 EFH since new or inspection, or No later than 30 June 2011
whichever comes first

Engines with 2 nd stage turbine blades having accumulated more than 900 EFH and less than 1800 EFH Within the next 800 EFH, or Before 2 nd stage turbine disk has accumulated 2 200 EFH since new or inspection, or No later than 30 June 2011
whichever comes first Arriel 1B

Engines with 2 nd stage turbine blades having accumulated less than 900 EFH since new Replace the 2 nd stage turbine disk and blades with aninspected preTU347 turbine fitted with new blades or a post-TU347 turbine in accordance with MSB A292 72 0807 Version E, Par. 2B(1)(c)or(d) or 2B(2)(b)or(c)

Before 2 nd stage turbine blades have accumulated 1 200 EFH since new For preTU347 turbine: Repeat replacement before 2 nd stage turbine blades have accumulated 1 200 EFH since new

For postTU347 turbine:
Not applicable

Note: EFH = Engine Flight HoursEASA AD No: 2009-0236

EASA Form 110 Page 6/6

Table 3.2: 2nd Stage Turbine Replacement Requirements – Arriel 1D, 1D1

Configuration Condition Action Compliance Time Repetitive Interval (Not to Exceed)
Engines with 2 nd stage turbine blades having accumulated more than 1 500 EFH since new, or 2 nd stage turbine disk having accumulated more than 1 500 EFH since new or inspection
whichever comes first Before next flight Note: Already required by AD 2007-0018R1

Engines with 2 nd stage turbine blades having accumulated more than 900 EFH and less than 1 500 EFH since new Before 2 nd stage turbine blades have accumulated 1 500 EFH since new, or Before 2 nd stage turbine disk has accumulated 1 500 EFH since new or inspection, or No later than 30 June 2011
whichever comes first Arriel 1D, 1D1

Engines with 2 nd stage turbine blades having accumulated less than 900 EFH since new Replace the 2 nd stage turbine disk and blades with aninspected preTU347 turbine fitted with new blades or a post-TU347 turbine in accordance with MSB A292 72 0807 Version E, Par. 2B(1)(c)or(d) or 2B(2)(b)or(c)

Before 2 nd stage turbine blades have accumulated 1 200 EFH since new For preTU347 turbine: Repeat replacement before 2 nd stage turbine blades have accumulated 1 200 EFH since new

For postTU347 turbine:
Not applicable

Note: EFH = Engine Flight Hours