# eurocopter an EADS Company EUROCOPTER DIRECTION TECHNIQUE SUPPORT 13725 MARIGNANE CEDEX FRAN CE 

# EMERGENCY T.F.S. No. 00000301 

# ALERT SERVICE BULLETIN DAUPHIN 

### ! NUMBER I 

### VERSIONS 

# 365 65.44 Civil: 

### C, C1, C2, C3 

# 365 62.00.22 1 Civil: 

### N , N 1, N2, N 3 : Military: F, Fs , Fi, 

### K 

# 565 62.00.08 ; Military : AA, MA, M B, SA, SB , UB 

### SUBJECT: MAIN ROTOR Check of the Main Rotor Hub-to-Mast Bolted Attachment 

### ATA: 

## 62 or 

## 65 REVISION No . Revision 0

Approved under EASA DOA No. 21J.056 

### DATE OF APPROVAL On: April10, 2006 

### DATE OF ISSUE 2006.04 . 10

Page 1/10 2006.04.10

# eurocopter an EADS Company T .F .S . No . 00000301 

### 2. ACCOMPLISHMENT INSTRUCTIONS 2.A. GENERAL Not applicable. 

### 2.8. OPERATIONAL PROCEDURE 2.B.1. Preliminary steps

- Remove the MGB cowlings, as per MET Work Card 53.50.00.401 or 53.50.401.

- Remove fairing (a). 2.B.2. Check of the tightening torque of the main rotor hub/mast assembly attachment bolts As per Figure 1:

- Remove the lockwire from bolt heads (b) .
- Measure the tightening torque of bolts (b), in accordance with the procedure described in MTC Work

Card 20.02.05.404.

- Put a mark on the head of any bolt (b) that has a tightening torque of less than 3.2 m.daN. Interpretation of the results: a) If the tightening torque of all the bolts (b) is equal to or more than 3.2 m.daN: 

### NOTE1 The 3. 2 m. daN tightening torque is indicative ofa loss of approximately 30% ofthe recommended minimum tightening torque for these attachment bolts.

- Carry out the following operation on each of the 16 bolts (b). one after the other:

. Loosen one bolt (b).
. Retain nut (c) and washer (d).
. Lubricate the thread of nut (c) and re-install washer (d) and nut (c).
. Torque tighten bolt (b) to the tightening torque specified on the Figure shown in MET Work Card

62.20.00.401 or 65.14.401.

- Lock the bolts (b) with lockwire , as per MET Work Card 62.20 .00.401 or 65.14.401.

- Comply with paragraph 2.B.3 .

Approved under EASA DOA No . 21J.056 Page 6/10 2006 .04.10

# eurocopter an EADS Company T.F.S . No. 00000301 b) Ifthe tightening torque of at least one of the bolts (b) is less than 3 .2 m.daN : 1) Attachment on which the tightening torque of less than 4 adjacent bolts (b) is less than 3.2 m.daN:

- One after the other, replace the bolts (b) that have a tightening torque of less than 3.2 m.daN,

as per MET Work Card 62.20.00.401 or 65.14.401.

- Apply the procedure described in paragraph 2.B.2.a. to the remaining bolts (b). 2) Attachment on which the tightening torque of more than 3 adjacent bolts (b) is less than 3.2 m.daN:

- Remove the main rotor, as per MET Work Card 62.20.00.401 or 65.14.401.

- Check the condition of the components, as per MET Work Card 62.30.00.601 or 65.13.601.

- Replace any bolts (b) that have a tightening torque of less than 3.2 m.daN.

- Re-install the main rotor, as per MET Work Card 62.20.00.401 or 65.14.401. 2.B .3. Final steps -Install fairing (a), as per MET Work Card 62.20.00.401 or 65.14.401. -Install the MGB cowlings, as per MET Work Card 53.50.00.401 or 53.50.401.

- If the main rotor was removed, carry out the operations defined in MET Work

Card 62.20.00.605 or 65.14.603. 

### 2.C. IDENTIFICATION Record compliance with this ALERT SERVICE BULLETIN in the aircraft documents. 

### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS Not applicable.

Approved under EASA DOA No 21J 056 Page 7/10 2006.04 10

# eurocopter an EADS Company

b ,

Figure 1

Approved under EASA DOA No 

### 21J 056 

### a 

### T.F .S. No. 00000301

Page 

### 8i10 2006 04 10