ALERT SERVICE BULLETIN AS350 

Approved under EASA DOA No. 21J.056. 05.00.60 Page 1/9

 2009.12.09

 

This document is available on the internet: www.eurocopter.com/techpub 

 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE CIVIL VERSION(S): B, BA, BB, D, B1, B2, 

B3 

 MILITARY VERSION(S): L1 

 ALERT SERVICE BULLETIN 

No. 05.00.60 

SUBJECT: TIME LIMITS - MAINTENANCE CHECKS

Check for no play in the tail rotor pitch-change links

ATA: 65

REVISION No. DATE OF APPROVAL DATE OF ISSUE 

 

Revision 0 On: December 08, 2009 2009.12.09 

 

 
 ALERT SERVICE BULLETIN AS350 

Approved under EASA DOA No. 21J.056. 05.00.60 Page 2/9

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CAUTION 

THE INFORMATION AND INSTRUCTIONS CONTAINED IN 

THIS ALERT SERVICE BULLETIN ARE INTENDED FOR 

MAINTENANCE PERSONNEL AND FLIGHT CREWS. 

1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters/installed equipment 

Helicopters equipped with tail rotor pitch-change links with part numbers: 

350A33-2100-00, 350A33-2100-01, 350A33-2100-02, 350A33-2100-03, 350A33-2100-04, 350A33-2121-00, 

350A33-2121-01, 350A33-2121-02, 350A33-2143-00, 350A33-2145-00 and 350A33-2145-01. 

1.A.2. Non-installed equipment 

Not applicable. 

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 

1.C. REASON 

To make the periodicity of the check for no play in tail rotor pitch-change links mandatory by introducing it in 

the Airworthiness Limitations Section (ALS) of the Maintenance Program (PRE). 

This ALERT SERVICE BULLETIN will form the subject of an EASA-Airworthiness Directive. 
 ALERT SERVICE BULLETIN AS350 

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1.D. DESCRIPTION 

On an AS350, the pilot felt slight vibrations in the pedal unit in flight. A few minutes later, the vibration level 

increased and the pilot carried out an autorotation. 

After landing, it was discovered that one tail rotor pitch-change link was deteriorated, that the tail-boom cone 

was missing and there was an impact mark on the tail-boom. 

Investigation of the pitch-change link has shown extensive wear on the ball-joint and failure of the web of the 

ball-joint due to fatigue. The deterioration of the pitch-change link concerned could have been discovered 

during the check for no play in the links. Currently, this check is scheduled at the check after the last flight of 

the day (ALF) without exceeding 30 flying hours. 

Any undiscovered deterioration of a pitch-change link can in time lead to the loss of the anti-torque function. 

EUROCOPTER therefore makes the periodicity of the check for no play in tail rotor pitch-change links, 

mandatory, in order to prevent any pitch-change link failure. 

Furthermore, EUROCOPTER provides some detailed information concerning the existing procedure to 

enable easier detection of play, if any. 

1.E. COMPLIANCE 

 EUROCOPTER makes compliance with this ALERT SERVICE BULLETIN mandatory. 

1.E.1. Compliance at the works 

1.E.1.a. On helicopters 

Not applicable. 

1.E.1.b. On non-installed equipment 

Not applicable. 

1.E.2. Compliance in service: By the operator 

1.E.2.a. On helicopters/installed equipment 

Comply with paragraph 2.B.1. within 30 flying hours following receipt of this ALERT SERVICE BULLETIN, 

issued on the date indicated at the foot of the page. 

Then, 

Comply with paragraph 2.B.2. at intervals not exceeding 30 flying hours. 

1.E.2.b. On non-installed equipment 

Not applicable. 
 ALERT SERVICE BULLETIN AS350 

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1.F. APPROVAL 

1.F.1. Approval of the modifications 

Not applicable. 

1.F.2. Approval of the Service Bulletin 

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on December 08, 2009 under the authority of EASA Design Organisation Approval No. 21J.056 for civil 

version helicopters subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on December 08, 2009 by the EUROCOPTER Airworthiness Department for military version helicopters. 

1.G. MANPOWER 

1.G.1. Qualification

EUROCOPTER recommends that compliance with this ALERT SERVICE BULLETIN is ensured by qualified 

personnel as follows: 

Qualification: 1 Mechanical Engineering Technician. 

or, 

1 suitably trained pilot, qualified in accordance with the local regulation. 

1.G.2. Time for the operations 

The operation times are given for information purposes and for a standard configuration. 

Time for the operations: Approximately 5 minutes. 

1.H. WEIGHT AND BALANCE 

 Not applicable. 

1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable. 

1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD 

Not applicable. 
 ALERT SERVICE BULLETIN AS350 

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1.K. REFERENCES 

The documents required for compliance with this ALERT SERVICE BULLETIN are as follows: 

MET: Work Card 65.20.00.601: Tail Gear-Box - Tail rotor pitch-change spider-Hub: 

Condition check. 

MET: Work Card 67.10.00.301: Rotor controls - General instructions. 

1.L. OTHER DOCUMENTS AFFECTED 

EUROCOPTER will modify the documents below in accordance with this ALERT SERVICE BULLETIN: 

- Maintenance Program (PRE), 

- Maintenance Manual (MET). 

These documents will be issued subsequently. 

1.M. TOOLING AFFECTED 

 Not applicable. 

1.N. INTERCHANGEABILITY OR MIXABILITY OF PARTS 

 Not applicable. 
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2. ACCOMPLISHMENT INSTRUCTIONS 

2.A. GENERAL 

- Read and comply with the general instructions as per MET Work Card 67.10.00.301. 

- The operational procedure below is applicable to the two tail rotor pitch-change links. 

2.B. OPERATIONAL PROCEDURE 

2.B.1. Check for no play in the pitch-change links (Figure 1) 

- Take the pitch-change link in your hand and position your thumb on the yoke of the blade control horn (see 

Detail B). 

- Move the pitch-change link parallel to the centerline of the ball-joint in a manner enabling you to detect 

play, if any. 

Whilst moving the pitch-change link: 

- With the other hand, move the blade in flapping direction (A), trying to find the position where axial play (if 

any) in the ball-joint is detectable (stress relieving in the pitch-change link). 

. If you feel any play J comply with paragraph 2.B.3. 

. If you feel no play J, leave as is. 

2.B.2. Check at regular intervals and interpretation of the results 

- If no play was felt during the previous check, comply with paragraph 2.B.1. 

- If play was measured during the previous check, comply with paragraph 2.B.3. 

2.B.3. Check of the ball-joints of the pitch-change links 

- Check the ball-joint of the pitch-change link in accordance with MET Work Card 65.20.00.601 

paragraph 4.2.1 “Pitch-change links”. Record the measured play value. 

2.C. IDENTIFICATION 

Record initial compliance with this ALERT SERVICE BULLETIN on the helicopter documentation. 

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

Not applicable. 
 ALERT SERVICE BULLETIN AS350 

Approved under EASA DOA No. 21J.056. 05.00.60 Page 7/9

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Figure 1: Check for no play in the pitch-change links 
 ALERT SERVICE BULLETIN AS350 

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3. MATERIAL INFORMATION

3.A. MATERIAL: PRICE AND AVAILABILITY 

3.A.1. Cost 

For all information concerning the kits and/or components, contact your usual sales representative. 

3.A.2. Availability 

The kits and/or components will be delivered on the operator’s order. 

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

3.C. MATERIAL REQUIRED FOR EACH HELICOPTER/ENGINE/COMPONENT 

3.C.1. Kits or components to be ordered for one helicopter or one assembly 

Not applicable. 

3.C.2. Products to be ordered separately 

The materials identified by an asterisk "*" or required for compliance with the Tasks and/or Work Cards listed in 

paragraph 1.K., can be ordered from the INTERTURBINE company: 

Website: http://www.itlogistics.de

Phone: +49.41.91.809.300 

AOG: +49.41.91.809.444. 
 ALERT SERVICE BULLETIN AS350 

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3.D. PROCUREMENT CONDITIONS

Order the required quantity (unless otherwise specified) 

from 

EUROCOPTER 

Etablissement de Marignane 

Direction Ventes et Relation Client 

ECR 

13725 MARIGNANE CEDEX 

FRANCE 

NOTE 1

For ALERT SERVICE BULLETINS, order by: 

Telex: HELICOP 410 969F 

Fax: +33 (0)4.42.85.99.96. 

NOTE 2

On the purchase order, please specify the mode of transport, 

the destination and the serial numbers of the helicopters to be 

modified. 

4. APPENDIX 

Not applicable.