### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 1/15

2008.12.01 This document is available on the Internet: www.eurocopter.com/techpub EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE C EDEX F RANCE



# EMERGENCY 

# ALERT SERVICE BULLETIN

ECUREUIL NUMBER VERSIONS

Civil: B-BA-BB-B1-B2-B3-D 

# AS350 05.00.58 Military: L1
Military: A2-C2-C3-U2 

# AS550 05.00.35

SUBJECT: 

## Time Limits – Maintenance Checks

Collective pitch lever locking stud

ATA: 67

REVISION No. DATE OF APPROVAL DATE OF ISSUE

Revision 0 On: 01/12/2008 01/12/2008

### T.F.S. No. 00000486

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2008.12.01 

### CAUTION

THE INFORMATION AND INSTRUCTIONS

CONTAINED IN THIS ALERT SERVICE BULLETIN

ARE INTENDED FOR MAINTENANCE PERSONNEL.



### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/installed equipment

- Helicopters delivered before modification 073175,

or - helicopters on which work has been carried out in se rvice on the locking studs or on the collective

pitch levers or on the locking strips,

or - helicopters having been subject to compliance with Re vision 0 or Revision 1 of Service Bulletins No.

67.00.37 (AS350) or No. 67.00.19 (AS550), corresponding to modification 073237,

or - helicopters with a serial number equal to: 3972-3973-3982-3987-4003-4023-4046-4050-4086-4120-

4122-4132-4143-4152-4172-4194-4259-4314-432 4-4378-4392-4447-4452-4477-4489-4490-4501-

4523-4546-4560-4589-4594-4599-4632-4659-4666-4671.



### NOTE 1

Service Bulletins No. 67.00.37 and No. 67.00.19 correspond to modification 073237 which consists in replacing the collective pitch lever locking stud, which was initially made from light alloy, with a longer locking stud made from steel (see Figure 1).



### NOTE 2

The modification 073175 consists in replacing the original flexible locking strip with a rigid strip with hinged lower end and returned to the forward position by a spring.



### NOTE 3

Refer to the Aircraft Individual Inspection Record (RIC), the Log Cards (FM) or the aircraft logbook to identify the actual configuration of the helicopter.

1.A.2. Non-installed equipment

Not applicable.

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 3/15

2008.12.01 

### 1.B. ASSOCIATED REQUIREMENTS

Not applicable.



### 1.C. REASON

To ensure that there is a minimum clearance between the end of the locking stud and the locking strip to prevent untimely locking of the collective pitch lever.

This ALERT SERVICE BULLETIN will form the subject of an EASA Airwor thiness Directive.



### 1.D. DESCRIPTION

EUROCOPTER has introduced the modification 073237, mentioned in paragraph 1.A.1., which prevents wear of the locking stud and thus preclude s the risk of untimely unlocking of the collective pitch lever during the starting phase. This modification has introduced a new locking stud which is longer than the previous one. For this reason, the clearance between the locking stud and the locking strip is reduced and in some cases it proves to be insufficient when the collecti ve pitch lever is positioned on the "low pitch" stop. In fact, on a helicopter during an autorotation test in flight, it was found that the collective pitch lever rubbed against the locking strip in the "low pitch" position (low position). This rubbing is due to

insufficient clearance and could result in untim ely locking of the collective pitch lever.

To preclude the risk of untimely locking, EUROCO PTER is introducing a mandatory measure to ensure a required minimum clearance and is providing a repair solution in case the clearance is

insufficient.

As a precautionary measure, this measure and repa ir if necessary are also extended to helicopters with locking studs pre-MOD 073237.



### 1.E. COMPLIANCE

EUROCOPTER renders 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.

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 4/15

2008.12.01 1.E.2. Compliance in se rvice: By the operator

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

- Comply with paragraph 2. during the ALF-check (c heck after the last flight of the day) following

receipt of this ALERT SERVICE BULLETIN, iss ued on the date indicated at the bottom of the

page, Then, - Comply with paragraph 2.B.2.a. or 2.B.3.a ., according to the helicopter configuration:

. each time the collective pitch lever, the lo cking stud or the locking strip is replaced, . each time the locking strip setting is readjusted, . at intervals not exceeding 660 hours or 2 y ears, the first limit reached is applicable.

If a flight is necessary to ferry the helicopter to a repair station or a place where the maintenance can be performed in order to comply with paragraphs 2.B.2.b, 2.B.2.c and 2.B.3.b., the flight is permitted with no passenger on board.

1.E.2.b. On non-installed equipment: Not applicable.



### 1.F. APPROVAL

Approval is limited to civil version helicopte rs subject to an Airworthiness Certificate.

The technical information given in this ALERT SERVICE BULLETIN was approved on
December 1, 2008 u nder the authority of EASA Design Or ganisation Approval No. 21J.056.

The information or instructions relate to change: MOD 350A088525 which was approved on November 21, 2008 under the authority of EASA Design Organisation A pproval No. 21J.056.



### 1.G. MANPOWER

Qualification: 1 Mechanic

Time for the operations: 10 minutes to co mply with paragraph 2.B.2.a. or 2.B.3.a. 1 hour to comply with paragraph 2. except paragraph 2.B. 2.a. or 2.B.3.a.



### 1.H. WEIGHT AND BALANCE

Not applicable.



### 1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD

Not applicable.

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 5/15

2008.12.01 

### 1.K. REFERENCES

Maintenance Manual (MET):

- Work Card 67.10.00.501

- Work Card 67.10.00.502

Standard Practices Manual (MTC):

- Work Card 20.02.05.404

- Work Card 20.02.06.402

- Work Card 20.04.04.404

- Work Card 20.04.05.402

- Work Card 20.08.05.103



### 1.L. OTHER DOCUMENTS AFFECTED

EUROCOPTER will modify the following document wi th respect to this AL ERT SERVICE BULLETIN:

MET.



### 1.M. TOOLING AFFECTED

Not applicable.



### 1.N. INTERCHANGEABILITY OR MIXABILITY OF PARTS

Not applicable.

### T.F.S. No. 00000486

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2008.12.01 

### 2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

Not applicable.



### 2.B. OPERATIONAL PROCEDURE

2.B.1. Preliminary steps

Not applicable.

2.B.2. Helicopters modified per modification 073237

2.B.2.a. Measurement of the clearance between t he end of locking stud (c) and strip (a) (Figure 2):

- Move collective pitch lever (b) to the "low pitch" position (low position) without locking it on strip (a).

- Measure clearance "J". - If clearance "J" is equal to or more than 3 mm, return the helicopter to flight configuration. - If clearance "J" is less than 3 mm, comply with paragraph 2.B.2.b.

2.B.2.b. Interpretation of the results:

For helicopters pre-modification 073175 : - verify that the grommet in locking st rip (a) is seated against the console:

. if the grommet in locking strip (a) is seated agai nst the console, comply with paragraph 2.B.2.c. . if the grommet in locking strip (a) is not seated ag ainst the console, restore the original profile of

the locking strip: . mark the position of locking strip (a) on the cons ole so that the locking strip can be re-installed

at the same location, . remove the locking strip (remove the 2 screws and the 2 washers), . on a workbench, clamp the locking strip in a vice fitted with soft jaws, . apply a load progressively to the locking strip in order to restore its original profile, . remove the locking strip from the vice and inst all it on the console (f it the 2 screws and the 2

washers), in the position marked previously , then once again measure clearance “J” as measured previously: . If clearance "J" is equal to or more than 3 mm, return the helicopter to flight configuration in

compliance with paragraph 2.B.4.,

. If clearance "J" is less than 3 mm, comply with paragraph 2.B.2.c.



### CAUTION

Replace locking strip (a) wi thin a time limit of 3 months if its original profile has been restored.

For helicopters post-modification 073175 : - comply with paragraph 2.B.2.c.

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 7/15

2008.12.01 2.B.2.c. Adjusting the length of the collective pitch lever locking stud post-modification 073237 (Figures 3 and 4)

- Remove and discard pin (d). - Cut and remove the lock-wire from the two screws (e). - Remove and retain the two screws (e). - If washers are fitted, remove and retain the two washers (f). - Remove locking stud (g). - File stud (g) to length as per Figure 4. - Break sharp edges with a 1 mm radius (R1).

- Protect the reworked area with MAGICB LUER + P05 + P20 (4) as per MTC Work

Cards 20.04.04.404 and 20.04.05.402. - Apply matt-black top coat paint (2). - Strike out the former part number of the lock ing stud and mark the new part number with white

paint as per paragraph 2.C. and as per MTC Work Card 20.08.05.103. - Attach locking stud (g) to the collective pitch lever with:

. pin (1), . the two screws (e) and two wash ers (f) if removed previously. - Torque tighten screws (e) as per MTC Work Card 20.02.05.404 then safety them with lock-wire (3)

as per MTC Work Card 20.02.06.402. - Verify that clearance "J" is equal to or more t han 3 mm as defined in paragraph 2.B.2.a. and return

the helicopter to flight configuration in accordance with paragraph 2.B.4.

2.B.3. Helicopters not modified per modification 073237

2.B.3.a. Measurement of the clearan ce between the end of locking stud (c) and locking strip (a) (Figure 2):

- Move collective pitch lever (b) to the "low pitch" position (low position) without locking it on strip (a).

- Measure clearance "J". - If clearance "J" is equal to or more than 3 mm, return the helicopter to flight configuration. - If clearance "J" is less than 3 mm, comply with paragraph 2.B.3.b.

2.B.3.b. Interpretation of the results:

For helicopters pre-modification 073175 : - verify that the grommet in locking st rip (a) is seated against the console:

. if the grommet in locking strip (a) is seated against the console, suspend flights and inform the

Customer Service Technical Support Departmen t (Département Support Technique du Service à la clientèle) in order to define the me thod to make the helicopter compliant: Fax: +33(0)4.42.85.99.66

E-mail: Hydraulics.technical-support@eurocopter.com

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 8/15

2008.12.01 . if the grommet in locking strip (a) is not seated ag ainst the console, restore the original profile of

the locking strip: . mark the position of locking strip (a) on the cons ole so that the locking strip can be re-installed

at the same location, . remove the locking strip (remove the 2 screws and the 2 washers), . on a workbench, clamp the locking strip in a vice fitted with soft jaws, . apply a load progressively to the locking strip in order to restore its original profile, . remove the locking strip from the vice and inst all it on the console (f it the 2 screws and the 2

washers), in the position marked previously , then once again measure clearance “J” as measured previously: . if clearance "J" is equal to or more than 3 mm, return the helicopter to flight configuration in

compliance with paragraph 2.B.4., . if clearance "J" is less than 3 mm, suspend f lights and inform the Customer Service Technical

Support Department (Département Support Techni que du Service à la clientèle) in order to define the method to make the helicopter compliant: Fax: +33(0)4.42.85.99.66

E-mail: Hydraulics.technical-support@eurocopter.com



### CAUTION

Replace locking strip (a) within a time limit of 3 months if its original profile has been restored.

For helicopters post-modification 073175 : . suspend flights and inform the Customer Servic e Technical Support Department (Département

Support Technique du Service à la clientèle) in order to define the method to make the helicopter compliant:

Fax: +33(0)4.42.85.99.66

E-mail: Hydraulics.technical-support@eurocopter.com

2.B.4. Final steps

- Check the adjustment of the locking strip as per the "Checking the adjustment" paragraph of:

. MET Work Card 67.10.00.501 for helicopters without autopilot, . MET Work Card 67.10.00.502 for helicopters with autopilot.

- If necessary, readjust the strip as per the "Adjus tment of the LOW PITCH locking strip" paragraph

of: . MET Work Card 67.10.00.501 for helicopters without autopilot, . MET Work Card 67.10.00.502 for helicopters with autopilot.

### T.F.S. No. 00000486

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2008.12.01 

### 2.C. IDENTIFICATION

Record first compliance with this ALERT SER VICE BULLETIN in the helicopter documents. Identify the new locking studs as per the Table below if compliance was ensured with paragraph

2.B.2.c.:

Key Word Former Part Number New Part Number Version Locking stud 350A27-3155-21 350A08-8525-25 B3-C3 Locking stud 350A08-2363-20 350A08-8525-25 B3-C3 Locking stud 350A27-3155-22 350A08-8525-26 B1-B2-BA-BB-B-D Locking stud 350A27-3155-23 350A08-8525-27 L1-A2-C2-U2



### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 10/15

2008.12.01 Figure 1: Modification 073237

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 11/15

2008.12.01 Figure 2: Measuring clearance "J" 

## J c a

J

a b

c 

## b

### T.F.S. No. 00000486

Approved under EASA DOA No. 21J.056 Page 12/15

2008.12.01 Figure 3: Removing/Installing the locking stud

### T.F.S. No. 00000486

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2008.12.01 

### Versions B3-C3 Versions B1-B2-BA-BB-D-B

Versions L1-A2-C2-U2

Figure 4: Adjusting the length of the locking stud

### T.F.S. No. 00000486

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2008.12.01 

### 3. MATERIAL INFORMATION

3.A. MATERIAL: PRICE AND AVAILABILITY

Not applicable.



### 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

Material P/N Qty Item Key Word Instructions

NSA5319-05-012 1 1 Pin Replace 350A27-3107-26 AR a Locking strip

3.C.2. Material to be ordered separately

Material P/N Qty Item Key Word Instructions

GM2-99NOIR AR 2 Paint
EN3628-0,5 AR 3 Lock-wire

MAGICBLUER+P05+P20 AR 4 Protection

The products necessary for complia nce with the Work Cards listed in paragraph 1.K. can be ordered from the INTERTURBINE company:

Website: http://www.itlogistics.de Telephone: +49.41.91.809.300

AOG : +49.41.91.809.444

3.C.3. Tools

Not applicable.

### T.F.S. No. 00000486

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2008.12.01 

### 3.D. 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 helicopters to be modified.



### 4. APPENDIX

Not applicable.