ALERT SERVICE BULLETIN EC155 

Approved under EASA DOA No. 21J.056. 67A007 Page 1/10

 2009.02.25 This document is available on the internet: www.eurocopter.com/techpub 

 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE CIVIL VERSION(S): B, B1 

 

 ALERT SERVICE BULLETIN 

No. 67A007 

SUBJECT: ROTOR FLIGHT CONTROLS

Check of the Collective Pitch Lever Restraining Tab

REVISION No. DATE OF APPROVAL DATE OF ISSUE 

 

Revision 0 On: January 20, 2006 2006.01.20 

Revision 1 On: February 23, 2009 2009.02.25 

 

 

 
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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 fitted with the collective pitch lever "low pitch" locking system and not modified per MOD 0767B65.

NOTE

MOD 0767B65 is introduced by Service Bulletin No. 67-009. 

Refer to the aircraft individual inspection record (MOD record), 

or the aircraft log book to identify the actual configuration of the 

helicopter. 

1.A.2. Non-installed equipment: Not applicable.

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 

1.C. REASON 

- To prevent the risk of: 

. untimely collective pitch lever locking, when the collective pitch lever is moved to the "low-pitch" position, 

. untimely collective pitch lever unlocking during engine starting. 

- Revision 0 of this ALERT SERVICE BULLETIN formed the subject of Revision 1 of 

Airworthiness Directive No. F-2005-127 issued by the DGAC on behalf of the EASA. 

- Revision 0 of this ALERT SERVICE BULLETIN: 

. superseded ALERT TELEX No. 67A007, dated June 30, 2005, 

. modified paragraphs 2.B.2., 2.B.3. and 3.C.3. and Detail B on Figure 1, with no change to the technical 

content: 

- specifying the various types of spring scales to be used: “pull type” spring scale (1) or “push type" spring 

scale (3), 

- providing additional information concerning the use of the “pull type” spring scale (NOTE in 

paragraph 2.B.2.). 

- Revision 1 of this ALERT SERVICE BULLETIN informs the users that helicopters modified per 

MOD 0767B65 (introduced by Service Bulletin No. 67-009) are not concerned by the instructions of this 

ALERT SERVICE BULLETIN. 

- Revision 1 of this ALERT SERVICE BULLETIN will form the subject of a new EASA Airworthiness 

Directive. 
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1.D. DESCRIPTION 

One of our operators has discovered two problems on the collective pitch lever locking system: 

- One case of untimely locking of the collective pitch lever, which occurred in flight, when moving the 

collective pitch lever to the "low pitch" position: The reason for this occurrence is attributed to an anomaly 

concerning the shape of the restraining tab. 

- One case of untimely unlocking of the collective pitch lever during engine starting. 

When the collective pitch lever is in the locked configuration, it should apply a minimum upward load to 

ensure that the restraining tab remains locked to the collective pitch lever. If this load is too low (in the 

event of incorrect adjustment), there is a risk of unwanted collective pitch lever unlocking. 

In view of the elements outlined above, EUROCOPTER renders compliance with this ALERT SERVICE 

BULLETIN mandatory. 

1.E. COMPLIANCE 

The following measures are mandatory since receipt of ALERT TELEX No. 67A007, issued on June 30, 2005. 

1.E.1. Compliance at the works 

1.E.1.a. On helicopters/installed equipment: Before delivery, comply with paragraph 2. of this ALERT SERVICE 

BULLETIN. 

1.E.1.b. 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. within the 50 flying hours following receipt of 

ALERT TELEX No. 67A007, issued on June 30, 2005 

1.E.2.b. Non-installed equipment: Not applicable. 

1.F. APPROVAL 

Approval is limited to civil version helicopters subject to an Airworthiness Certificate. 

The technical information contained in Revision 0 of this ALERT SERVICE BULLETIN No. 67A007 was 

approved on January 20, 2006 under the authority of EASA Design Organisation Approval No. 21J.056. 

The technical information contained in Revision 1 of this ALERT SERVICE BULLETIN No. 67A007 was 

approved on February 23, 2009 under the authority of EASA Design Organisation Approval No. 21J.056. 

1.G. MANPOWER 

Qualification: 1 mechanic. 

Time: Approximately 1 hour. 
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1.H. WEIGHT AND BALANCE 

Weight: Not applicable. 

Moment: Not applicable. 

1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable. 

1.J. SOFTWARE MODIFICATION EMBODIMENT STATE 

Not applicable. 

1.K. REFERENCES 

- Aircraft Maintenance Manual (AMM): 

Tasks: 24-00-00-481, 

24-00-00-911, 

29-00-00-911, 

29-12-00-481. 

1.L. OTHER DOCUMENTS CONCERNED 

Aircraft Maintenance Manual (AMM). 

Maintenance Program (MSM). 

1.M. INTERCHANGEABILITY OR MIXABILITY OF PARTS 

Not applicable. 
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2. ACCOMPLISHMENT INSTRUCTIONS 

2.A. GENERAL 

- Comply with the electrical power general instructions as per AMM, Task 24-00-00-911. 

- Comply with the hydraulic power general instructions as per AMM, Task 29-00-00-911. 

2.B. OPERATIONAL PROCEDURE 

2.B.1. Preliminary steps 

- Pressurize the hydraulic power system as per AMM Task 29-12-00-481. 

- Energize the aircraft electrical power system as per AMM Task 24-00-00-481. 

2.B.2. Check focused on the risk of collective pitch lever (C) unlocking (Figure 1 - Detail B) 

- Lock the collective pitch lever (C). 

- Using a “pull type” spring scale (1) or a “push type” spring scale (3), measure the load "G" required to 

unlock the pilot's collective pitch lever (C). 

NOTE

If you use a “pull type” spring scale (1), it shall be kept slightly 

away from the console to be able to measure the load “G”. 

- If the collective pitch lever (C) unlocks at: 

. a load 11 < G < 14 daN, the adjustment is correct: 

- comply with paragraph 2.B.4., 

. a load "G" outside the range above, the adjustment is incorrect: 

- comply with paragraph 2.B.3. 

2.B.3. Adjustment of collective pitch lever (C) unlocking (Figure 1 - Detail B) 

- Adjust the restraining tab (F) using the oblong holes, in such a way that the collective pitch lever (C) 

unlocks at a load 11 < G < 14 daN, measured using a “pull type” spring scale (1) or a “push type” spring 

scale (3). 

- Comply with paragraph 2.B.4. 
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2.B.4. Check focused on the risk of unwanted locking (Figure 1 - Detail A) 

- Set the collective pitch lever to the "low pitch" position and hold it in this position, without forcing 

downwards. 

- Tighten the friction lock. 

- Check the clearance "J1" between the locking pin of the collective pitch lever (C) and the L-section of the 

restraining tab (F). 

. If J1 > 3 mm, the adjustment is correct: 

- loosen the friction lock, 

- return the helicopter to its original configuration in compliance with paragraph 2.B.6. 

. If J1 < 3 mm, the adjustment is incorrect: 

- loosen the friction lock, 

- modify the shape of the restraining tab (F) in compliance with paragraph 2.B.5. 

2.B.5. Modifying the shape of the restraining tab (F) (Figure 1) 

CAUTION 

DO NOT UNBEND THE RESTRAINING TAB (F) AFTER 

HAVING BENT IT. 

- Identify the position of the restraining tab (F) on the console so that it can be re-installed at the same 

location after removal. 

- Remove the restraining tab (F): screws (D), washers (E), Detail A. 

- On a workbench: 

. Clamp the restraining tab (F) in a vice (2) fitted with soft jaws, as shown on Detail K. 

. Gradually apply a load "H" to the restraining tab (F) (Detail K), until it is lightly distorted, in order to ensure 

a clearance J1 > 3 mm, on the helicopter. 

- Install the restraining tab (F) at the position previously identified: screws (D), washers (E), Detail A. 

. If J1 > 3 mm, the adjustment is correct: 

- comply with paragraph 2.B.2., to ensure that the load "G" is still within the 11 to 14 daN range. 

. If J1 < 3 mm, further distort the restraining tab (F) in the vice (2). 

2.B.6. Final steps 

- De-energize the aircraft electrical power system as per AMM Task 24-00-00-481. 

- Cut the hydraulic power supply of the helicopter as per Task 29-12-00-481. 
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2.C. IDENTIFICATION 

Record compliance with this ALERT SERVICE BULLETIN in the aircraft documents. 

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

2.D.1. Operating instructions: Not applicable. 

2.D.2. Maintenance instructions: 

A routine check to be carried out in addition to the current maintenance will be incorporated in the 

Aircraft Maintenance Manual (AMM) and in the Maintenance Program (MSM) through a Revision. 
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Figure 1: Collective pitch lever and restraining tab 
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3. MATERIAL INFORMATION

3.A. MATERIAL: COST - AVAILABILITY 

For any information concerning kits and/or components, contact the Sales and Customer Relations 

Department of the EUROCOPTER Network. 

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

3.C. MATERIAL REQUIRED FOR EACH AIRCRAFT, ENGINE/COMPONENTS 

3.C.1. Component(s) 

Not applicable. 

3.C.2. Items to be ordered separately 

Not applicable. 

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 

3.C.3. Tooling 

Part Number Qty Item Key Word 

 

/ 

/ 

A/R 

A/R 

1 

3 

“Pull type” spring scale 

or 

“Push type” spring scale 

 
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3.D. MATERIAL REQUIRED FOR EACH SPARE PART 

Not applicable. 

3.E. RE-IDENTIFIED PARTS 

Not applicable. 

3.F. TOOLING: COST – AVAILABILITY 

Not applicable. 

3.G. PROCUREMENT CONDITIONS

Order the required quantity (unless otherwise specified) 

from 

EUROCOPTER 

Etablissement de Marignane 

Direction Ventes et Relations 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 aircraft to be 

modified. 

4. APPENDIX 

Not applicable.