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 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 Airworthiness Directive applies, except in accordance with the requirements of that Airworthiness Directive 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 : 

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 2007-0018R1, dated 14 August 2007. 

ATA 72 Engine – Gas Generator 2nd 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 decided to implement mandatory check and 

replacement of the turbine in order to reduce the probability of uncommanded 

engine IFSD. 

EASA AD 2007-0018 retained the requirements of previous DGAC AD 

F-2004-047 and included changes with regard to ARRIEL 1B engines only. 

Reduction of the turbine blade life limit from 6 000 hours to 3 000 hours was taken 

as a precautionary measure following 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 Turbine 
EASA AD No: 2009-0236 

EASA Form 110 Page 2/6 

incorporates improvements that are the terminating 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 2007-0018R1 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, lowering the life limits of the 2nd stage turbine blades, and 

lowering replacement thresholds of the 2nd 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 checks 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 2nd 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 2nd Stage Turbine Blades

3. Replacement of the 2nd 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 2009 
EASA 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 substantiated, 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 received during the consultation period. 

3. Enquiries regarding this AD should be referred to the Airworthiness 

Directives, Safety Management & Research Section, Certification Directorate, 

EASA. E-mail ADs@easa.europa.eu. 

4. For any questions concerning the technical 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.com
EASA 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 2nd 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 2nd 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 C 
EASA AD No: 2009-0236 

EASA Form 110 Page 5/6 

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

Configuration 2nd 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 2nd stage 

turbine blades having 

accumulated more than 

3 000 EFH since new, or

2nd 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 2nd 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 2nd stage 

turbine blades have 

accumulated 3 000 

EFH since new, or

Before 2nd stage 

turbine disk has 

accumulated 2 200 

EFH since new or 

inspection, or

No later than 30 June 

2011 

whichever comes first

Engines with 2nd stage 

turbine blades having 

accumulated more than 

900 EFH and less than 

1800 EFH 

Within the next 800 

EFH, or

Before 2nd 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 2nd stage 

turbine blades having 

accumulated less than 900 

EFH since new 

Replace the 2nd

stage turbine 

disk and blades 

with an 

inspected 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 2nd stage 

turbine blades have 

accumulated 1 200 

EFH since new 

For preTU347 

turbine: 

Repeat 

replacement 

before 2nd

stage turbine 

blades have 

accumulated 

1 200 EFH 

since new 

For postTU347 

turbine: 

Not 

applicable 

Note: EFH = Engine Flight Hours 
EASA 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 2nd stage 

turbine blades having 

accumulated more than 

1 500 EFH since new, or

2nd 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 2nd stage 

turbine blades having 

accumulated more than 

900 EFH and less than 

1 500 EFH since new 

Before 2nd stage 

turbine blades have 

accumulated 1 500 

EFH since new, or

Before 2nd 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 2nd stage 

turbine blades having 

accumulated less than 900 

EFH since new 

Replace the 2nd

stage turbine 

disk and blades 

with an 

inspected 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 2nd stage 

turbine blades have 

accumulated 1 200 

EFH since new 

For preTU347 

turbine: 

Repeat 

replacement 

before 2nd

stage turbine 

blades have 

accumulated 

1 200 EFH 

since new 

For postTU347 

turbine: 

Not 

applicable 

Note: EFH = Engine Flight Hours