# ASB No. AS355-05.00.59

Revision 0 2011-08-30 Approved under EASA DOA No. 21J.056. Page 1/9

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

### Civil version(s): E, F, F1, F2, N, NP



# ALERT SERVICE BULLETIN

SUBJECT : TIME LIMITS - MAINTENANC E CHECKS - Tail rotor control

Checking the locking of the stop scr ews of the yaw flight controls

ATA: 67



### Revision No. Date of issue

Revision 0 2011-08-30



### Summary :

Compliance with this ALERT SERVICE BULLETIN consists in checking the locking of the yaw channel stops.



### Compliance :

Compliance with this ALERT SERVICE BULLETIN is mandatory. For the attention of

# ASB No. AS355-05.00.59

Revision 0 2011-08-30 Approved under EASA DOA No. 21J.056. Page 2/9

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### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/installed equipment

AS355 helicopter versions E, F, F1, F2, N, NP equipped with the Automatic Pilot (AP).

or,

AS355 helicopter versions N and NP not equipped with the AP, embodying modification 071908.



### NOTE

Refer to the aircraft individu al inspection record (MOD

record) and 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

During take-off with sling load on an AS350 B3 helicopter, the pilot noticed that he reached one of the yaw

stops before its usual position. The mechanic found that the locknut of the yaw stop was loose and that the

yaw stop was out of adjustment.

The yaw stop screws of the flight controls of AS355 helicopters are identical to those of AS350 helicopters.

The loss of locking can lead to the loss of adjus tment of the stop concerned and cause a limited yaw

authority.

Consequently, pending a modification, EUROCOPTER renders the periodic check of the locking of the yaw

channel stop screws, mandatory.

Revision 0 of this ALERT SERVICE BULLETIN will form the subject of an EASA Airworthiness Directive.



### 1.D. DESCRIPTION

Compliance with this ALERT SERVICE BULLETIN consists in:

- checking the locking of the stop screws,

- if necessary, adjusting the stops,

- marking a line of paint on the screw/nut assembly,

- checking periodically the alignment of the paint line on the screw/nut assembly.

# ASB No. AS355-05.00.59

Revision 0 2011-08-30 Approved under EASA DOA No. 21J.056. Page 3/9

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### 1.E. COMPLIANCE

1.E.1. Compliance at the works

Helicopters/installed equipment :

Before delivery, comply with paragraph 3.B.2. of this ALERT SERVICE BULLETIN, issued on the date

indicated at the bottom of the page.

Non-installed equipment :

Not applicable.

1.E.2. Compliance in service

The operations on the helicopter are to be performed by the operator.

Helicopters/installed equipment :

Comply with paragraph 3.B.2. within 110 flying hours following receipt of this ALERT SERVICE BULLETIN,

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

then,

comply with paragraph 3.B.3. every 110 flying hours.

Non-installed equipment :

Not applicable.



### 1.F. APPROVAL

Approval of modifications:

Not applicable.

Approval of this document :

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

on August 26, 2011 under t he authority of EASA Design Organization Approval No. 21J.056 for helicopters

of civil versions subject to an Airworthiness Certificate.

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

on August 26, 2011 under the prerogatives of the recognition of design capability FRA21J-002-DGA for

French Government helicopters.

# ASB No. AS355-05.00.59

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### 1.G. MANPOWER

EUROCOPTER recommends that compliance with this ALERT SERVICE BULL ETIN is ensured by

personnel with the following qualifications:

Qualification: - 1 Mechanical Engineering Technician

The time for the operations is given for information purposes, for a standard configuration.

Time for the operations: - approximately 10 mi nutes for compliance with paragraph 3.B.2.

- approximately 10 minutes for compliance with paragraph 3.B.3.



### 1.H. WEIGHT AND BALANCE

Weight and moment negligible.



### 1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD

Not applicable.



### 1.K. REFERENCES

The following documents are required for compliance with this ALERT SERVICE BULLETIN.

MET: 67.10.00.301: MAIN ROTOR CO NTROLS: General instructions

MET: 67.20.00.502: TAIL ROTOR CONTROLS - Riggi ng: Versions E,F,F1,F2 "WITH AUTOMATIC PILOT",

Version N "WITH AND WITHOUT AP"

MTC: 20.04.01.102: CLEANING - Desc ription and use of standard cleani ng products for individual parts

and on aircraft

# ASB No. AS355-05.00.59

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### 1.L. DOCUMENTS AFFECTED

EUROCOPTER will update the Mainten ance Program (PRE) in ac cordance with this ALERT SERVICE BULLETIN.

The document concerned will be updated as part of a future revision.



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

Not applicable.

# ASB No. AS355-05.00.59

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### 2. MATERIAL INFORMATION

2.A. MATERIAL: PRICE - AVAILABILITY - PROCUREMENT

Not applicable.



### 2.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.



### 2.C. MATERIAL REQUIRED FOR EACH HELICOPTER/COMPONENT

Products to be ordered separately :

Refer to the Work Cards specified in this ALERT SERVICE BULLET IN and the list below:

Key Word Qty Product P/N CM Item

No.

red paint A/R Off the shelf / 1

The products can be ordered separately from the INTERTURBINE AVIATION LOGISTICS company.

Website: http://www.interturbine.com

Telephone: +49.41.91.809.300

AOG: +49.41.91.809.444



### 2.D. MATERIAL TO BE RETURNED

Not applicable.

# ASB No. AS355-05.00.59

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### 3. ACCOMPLISHMENT INSTRUCTIONS

3.A. GENERAL

Read and comply with the general instructions conc erning flight controls as per MET Work Card

67.10.00.301.



### 3.B. OPERATIONAL PROCEDURE

3.B.1. Preliminary steps

- Open the baggage compartment.

- Remove all panels or trimmings as required for access to the different work areas.

3.B.2. Initial check of t he locking of the stop screws (Figure 1)

- Check using a screwdriver for recessed head screws t hat the screws (a) (Figure 1) of the yaw stops do not

turn:

. If a stop screw (a) turns:

- adjust the stops as per MET Work Card 67.20.00.502,

- mark a line of red paint (1) on the scre w/nut assembly (Section B-B, Figure 1).

. If no stop screw (a) turns:

- mark a line of red paint (1) on the scre w/nut assembly (Section B-B, Figure 1).

3.B.3. Periodic check of t he locking of the stop screws (Figure 1)

- Check the locking of the stop screw by making sure t hat the red paint lines on the screw (a) and on the nut

(b) are aligned:

. if the red paint lines are aligned:

- leave as is.

. if the red paint lines are not aligned:

- inform the Technical Support Department of EUROCOPTER:

Fax: + 33 (0)4.42.85.99.66.

E-mail : Hydraulics.Technical- Support@eurocopter.com

- clean the marks of red paint on the screw (a) and the nut (b).

- adjust the stops as per MET Work Card 67.20.00.502,

- mark a line of red paint (1) on the scre w/nut assembly (Section B-B, Figure 1)

3.B.4. Final steps

- Install all panels and trimmings removed during preliminary steps (paragraph 3.B.1.).

- Close the baggage compartment.

# ASB No. AS355-05.00.59

Revision 0 2011-08-30 Approved under EASA DOA No. 21J.056. Page 8/9

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### 3.C. IDENTIFICATION

Identification of this document :

Record initial compliance with this document and its revision number in the helicopter documents.



### 3.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.

# ASB No. AS355-05.00.59

Revision 0 2011-08-30 Approved under EASA DOA No. 21J.056. Page 9/9

This document is available on the internet: www.eurocopter.com/techpub Figure 1 

## A

B B B B a

a 

## SECTION

B - B

a 1

b