## ASB MBB-BK117 C-2-85A-041

PAGE 1 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub Valid for Version(s): C ‐ 2. 

# EMERGENCY 

# ALERT SERVICE BULLETIN
SUBJECT : OPTIONAL EQUIPMENT ‐ External Mounted Hoist System Unintended detachment of hoist damper unit

Revision No. Date of issue

Revision 0 2013 ‐ 12 ‐ 18 Revision 1 2014 ‐02 ‐ 27 Revision 2 2014 ‐03 ‐05 Revision 3 2015 ‐02 ‐03 Revision 4 2015 ‐02 ‐ 12 Summary: With Revision 4 of this of this Emergency Alert Service Bulletin, Airbus Helicopters Deutschland introduces the measures required to reactivate the Goodrich hoist damper units. Reason for last Revision: Please replace Revision 3 of Emergency Alert Service Bulletin MBB ‐ BK117 C ‐ 2 ‐ 85A‐041 with Revision 4. With Revision 4 of this Emergency Alert Service Bulletin, Airbus Helicopters Deutschland introduces a single ‐ piece retainer and an improved assembly sequence of the hoist damper unit. Compliance: Airbus Helicopters Deutschland considers the c ompliance with this Alert Service Bulletin as mandatory.

## ASB MBB-BK117 C-2-85A-041

PAGE 2 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 

### 1 PLANNING INFORMATION 1.A EFFECTIVITY 1.A.1 Helicopters/installed equipment and parts a) MBB ‐ BK117 C ‐ 2, all S/N, equipped with Goodrich external mounted hoist. b) Goodrich hoist damper unit P/N 44307 ‐480, P/N 44307 ‐480 ‐ 1, P/N 44307 ‐480 ‐ 2 with split retainers 42305 ‐ 286. 1.A.2 Non ‐ installed equipment and parts See Section 1.A.1 b). 1.B ASSOCIATED REQUIREMENTS The accomplishment of EASB MBB ‐ BK117 C ‐ 2 ‐ 85A‐041 Revision 2 (see appendix) is a precondition for the accomplishment of Revision 4 of this EASB. 1.C REASON Airbus Helicopters Deutschland (AHD) had been informed about MBB ‐ BK117 C ‐ 2 ‐ related incidents during which the cable unintentionally detached from the Goodrich rescue hoist damper units while the unloaded unit was being lifted by hand. With Revision 2 of the EASB MBB ‐ BK117 C ‐ 2 ‐ 85A‐041, AHD introduced as a first measure the modification of the bonding strap unit and an improved retaining ring (see Appendix of this Alert Service Bulletin). With Revision 3 of the EASB MBB ‐ BK117 C ‐ 2 ‐ 85A‐041, a deactivation of the Goodrich hoist damper units was prescribed. Revision 4 of the EASB MBB ‐ BK117 C ‐ 2 ‐ 85A‐041 introduces a single ‐ piece retainer, an improved assembly sequence of the damper unit and the reactivation of the Goodrich hoist damper units. 1.D DESCRIPTION Replace the split retainers by the single ‐ piece retainer. 1.E COMPLIANCE 1.E.1 Compliance at H/C manufacturer level Helicopters/installed equipment and parts: The split retainers must be replaced with the single ‐ piece retainer i.a.w. Section 3.B.1 before delivery of a helicopter equipped with a Goodrich external mounted hoist. Non ‐ installed equipment and parts: The split retainers must be replaced with the single ‐ piece retainer i.a.w. Section 3.B.1 before delivery of a Goodrich hoist with Goodrich hoist damper unit or delivery of a Goodrich hoist damper unit.

## ASB MBB-BK117 C-2-85A-041

PAGE 3 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 1.E.2 Compliance in service Helicopters/installed equipment and parts: The split retainers must be replaced with the single ‐ piece retainer i.a.w. Section 3.B.1 before next hoist operation. Non ‐ installed equipment and parts: The split retainers must be replaced with the single ‐ piece retainer i.a.w. Section 3.B.1 before next hoist operation. 1.F APPROVAL Approval of this document: The information or instructions contained in this document refer to change no. 3672. The technical content of this document is approved under the authority of DOA No. EASA.21J.034. 1.G MANPOWER Not applicable. 1.H WEIGHT AND BALANCE Not applicable. 1.I POWER CONSUMPTION Not applicable. 1.J SOFTWARE UPGRADES/UPDATES Not applicable. 1.K REFERENCES Goodrich Component Maintenance Manual (CMM) 25 ‐00 ‐ 21 ‐ 1. 1.L OTHER AFFECTED PUBLICATIONS Publications already updated: Not applicable. Publications to be updated: Not applicable. 1.M INTERCHANGEABILITY OR MIXABILITY OF PARTS Interchangeability: Not applicable. Mixability: Not applicable.

## ASB MBB-BK117 C-2-85A-041

PAGE 4 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 

### 2 MATERIAL INFORMATION 2.A MATERIAL: PRICE ‐ AVAILABILITY ‐ PROCUREMENT Information on price and availability of required retrofit kit SB-117C2-85A-041-2C-1 will be provided by Airbus Helicopters Deutschland, Dept. Spares Order Administration on request. 2.B LOGISTIC INFORMATION Not applicable. 2.C MATERIAL REQUIRED PER HELICOPTER/COMPONENT Kits or components to be ordered for one assembly: Retrofit kit SB ‐ 117C2 ‐ 85A‐041 ‐ 2C ‐ 1. No. Keyword Qty New P/N Old P/N Remark

1 Retaining ring 1 M2742630109D or AS3217--109 -- A 2 Single--piece retainer 1 B851M2060201 -- -- Split retainer -- 42305--286 -- Remark: A = The retaining ring is a standard norm part and can be ordered locally. Consumable materials to be ordered separately: Consumable materials have to be ordered from the INTERTURBINE AVIATION LOGISTICS company. The given CM numbers are IAW the AMM list of consumable materials. Website: http://www.interturbine.com Phone: +49.41.91.809.300 AOG: +49.41.91.809.444 No. Keyword Qty. Specification ** CM Remark

1 Laquer, single layer a.n.* -- 421 -- *a.n. = as needed ** Specification IAW AMM, 01-00-00, 2-1. 2.D MATERIAL TO BE RETURNED Not applicable.

## ASB MBB-BK117 C-2-85A-041

PAGE 5 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 

### 3 ACCOMPLISHMENT INSTRUCTIONS 3.A GENERAL Not applicable. 3.B WORK STEPS 3.B.1 Replacement of the split retainers by a single ‐ piece retainer NOTE To get better access to the hoist damper unit, reel out approx. 2 meters of the hoist cable. 1. Remove the hook assembly (2, Figure 1) as follows: NOTE The hook mount and the damper housing (1) are a serialized matched set. a. Remove the lock spring (3, Figure 1) from the hook assembly (2). b. Unscrew the hook assembly (2) together with the hook and the attached bonding strap unit and remove from the damper housing (1). c. Pull the hook assembly (2) out of the damper housing (1). 2. Remove the shock attenuator as follows: NOTE The attenuator housing (5, Figure 1) and the damper housing (1) are a serialized matched set. a. Remove the lock spring (4) from the shock attenuator assembly (10). b. Unscrew the shock attenuator assembly (10) and remove from the damper housing (1). 3. Remove the shock attenuator from the hoist cable as follows: a. Remove and discard the retaining ring (9). b. Remove the bonding probe assembly (8) . c. Remove and discard split retainers (7). d. Remove the seat retainer (6) and attenuator housing (5) from the hoist cable. 4. Remove the hoist cable from the rescue hoist i.a.w. CMM 25 ‐00 ‐ 21 ‐ 1. 5. Install single ‐ piece retainer as follows: NOTE Ensure correct alignment and order of the parts i.a.w. Figure 2. a. First, slip the single ‐ piece retainer (1, Figure 2) over the hoist cable, followed by the seat retainer (2) and the shock attenuator housing (3). b. Install the hoist cable on the rescue hoist i.a.w. CMM 25 ‐00 ‐ 21 ‐ 1.

## ASB MBB-BK117 C-2-85A-041

PAGE 6 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub CAUTION RESPECT THE WARNINGS AND NOTES CONCERNING REELING IN THE HOIST CABLE GIVEN IN THE CMM, 25 ‐00 ‐21 ‐ 1. c. Carefully reel in the hoist cable until approx. 2 meters of extended cable are left. 6. Assemble the shock attenuator as follows: a. Use the hoist cable to pull the single ‐ piece retainer (1, Figure 2) and the seat retainer (2) into the shock attenuator housing (3). b. Insert the bonding probe assembly (8, Figure 1) into the shock attenuator housing (5) and secure with a new retaining ring (9). c. Visually check the retaining ring (9) for proper installation. d. Screw the shock attenuator assembly (10) into the damper housing (1). e. Install the lock spring (4) in the shock attenuator assembly (10). 7. Install the hook as follows: CAUTION CAREFULLY INSERT THE BONDING STRAPS OVER THE BONDING PROBE. MISALIGNMENT BETWEEN BONDING STRAP AND BONDING PROBE MAY LEAD TO DAMAGE ON THE RETAINING RING. a. Screw hook assembly (2, Figure 1) with the attached bonding strap into the bottom of the damper housing (1). Ensure that the tips of the bonding straps (1, Figure 3) are located over the bonding probe (2) inside the damper housing. 8. Identify the damper housing as follows: a. Using a permanent pen, identify the damper housing close to its P/N with “EASB ‐ 85A‐041 Rev 4” (see , Figure 1). b. Protect identification with laquer, single ‐ layer (CM 421). Let laquer, single ‐ layer dry i.a.w. manufacturer’s instruction. 3.B.2 Reactivate the Goodrich hoist (if deactivated with Revision 3 of this EASB): 1. Remove ty ‐ raps and push the following circuit breakers:

‐ WINCH BOOM

‐ WINCH CONT

‐ CC PIL WINCH

‐ CC PED WINCH 2. Remove the placard with printed inscription “External Mounted Hoist deactivated” previously affixed to a location within the pilot’s field of view. 3.C COMPLIANCE CONFIRMATION Compliance with this document: Confirm accomplishment of this Alert Service Bulletin by an entry in the historical record of the helicopter and in the log card of the external mounted hoist.

## ASB MBB-BK117 C-2-85A-041

PAGE 7 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 3.D OPERATING AND MAINTENANCE INSTRUCTIONS Additional information for the use of the load check tool after compliance with this Alert Service Bulletin: NOTE The load check is described in Goodrich Alert Service Bulletin 44301 ‐ 10 ‐ 18 and Goodrich Service Information Letter SIL‐ 2014 ‐01 CAUTION FOLLOW THE INSTRUCTIONS OF ALERT S ERVICE BULLETIN SECTION 3.B.1 WHEN REMOVE THE SHOCK ATTENUATOR ASSEMBLY (10, FIGURE 1): REMOVE HOOK ASSEMBLY (2, FIGURE 1) BEFORE INSTALLING SHOCK ATTENUATOR ASSEMBLY (10). THIS WILL MINIMIZE THE RISK OF MISALIGNMENT BETWEEN BONDING STRAP AND BONDING PROBE. 1. Load check using the load check tool with the shock attenuator adapter 49900 ‐ 893 (Goodrich SIL‐ 2014 ‐01, Page 8): a. There is no change in the procedure for the load check using the load check tool. 2. Load check using the load check tool without the shock attenuator adapter 49900 ‐ 893 (see Figure 4): a. Reel out approx. 2 meters of the hoist cable. b. Remove the lock spring (4, Figure 1) from the shock attenuator assembly (10). c. Unscrew the shock attenuator assembly (10) from the damper housing (1). d. Remove retaining ring (9) and discard. e. Remove bonding probe assembly (8). f. Insert the ball end of the hoist cable into the load check tool i.a.w. Goodrich SIL‐ 2014 ‐01. g. Position the attenuator housing (3, Figure 4), the seat retainer (2) and the single ‐ piece retainer (1) inside the Hook Adapter 49900 ‐ 891 (4). h. Accomplish the load check. i. Assemble the attenuator i.a.w. Section 3. B.1, task 6 of this Alert Service Bulletin. j. Install hook i.a.w. Section 3.B.1, task 7 of this Alert Service Bulletin. 

### 4 APPENDIX Modification of the bonding straps in accordance with ASB MBB ‐ BK117 C ‐ 2 ‐ 85A‐041 Revision 2.

## ASB MBB-BK117 C-2-85A-041

PAGE 8 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub Goodrich Hoist Damper Unit Figure 1 1 Damper housing 2 Hook assembly 3 Lock spring 4 Lock spring 5 Attenuator housing 6 Seat retainer 7 Single ‐ piece retainer B851M2060201 Split retainer 42305 ‐286 8 Bonding probe assembly 9 Retaining ring M2742630109D or AS3217 ‐ 109 10 Shock attenuator assembly 1

2 3 4
5 6 7 8

9 10 Identify with “EASB-85A-041 Rev 4” After modification. Before modification.

## ASB MBB-BK117 C-2-85A-041

PAGE 9 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub Installation of the Single ‐ Piece retainer Figure 2 1 Single ‐ piece retainer 2 Seat retainer 3 Attenuator housing

1 2 3 Marked with a serial number on the bottom side.

Upper end of the hoist cable.

## ASB MBB-BK117 C-2-85A-041

PAGE 10 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 1

3

1 Bonding strap 2 Bonding probe 3 Damper housing

Correct Assembly of Bonding Straps over Bonding Probe Figure 3 2

## ASB MBB-BK117 C-2-85A-041

PAGE 11 of 11 Revision 4, 2015-02-12 This document is available on the internet: www.airbushelicopters.com/techpub 1 2

1 Single piece retainer 2 Seat retainer 3 Attenuator housing 4 Hook Adapter 49900 ‐ 891

Using of the Load Check Tool without Shock Attenuator Adapter Figure 4 3

4 Step 1

Step 2

Step 3ASB MBB-BK117 C-2-85A-041

Revision 2 3.B. OPERATIONAL PROCEDURE 3.B.1. Modification of the hoist damper unit (a) Disassemble the hook assembly as follows: NOTE The hook mount (4, Figure 1) and the damper housing (1) are a serialized matched set. 1 Remove the lock spring (3, Figure 1) from the hook mount (4). 2 Unscrew the hook (5) together with the hook mount (4) and the attached bonding strap unit (2) from the damper housing (1). 3 Pull the bonding strap unit (2) together with the hook (5) and the hook mount (4) out of the damper housing (1). (b) Modify the bonding strap unit as follows: NOTE If a radius gauge with radius 3.2 mm is not available, manufacture a gauge out of sheet metal and a 6.4 mm drill (see Figure 2 and 3). NOTE Be careful to only round off the corners without shortening the total length of the bonding strap legs. 1 By using a radius gauge with 3.2 mm radius, round off the corners at the end of each bonding strap leg using a suitable tool i.e. a file, a grinder, etc. IAW Figure 4 and Figure 5. 2 Deburr and round all edges at the bonding strap ends IAW Figure 5 and Figure 6. 3 Remove all metal chips with a vaccum cleaner. 4 Using a permanent pen, cross out the old P/N on the bonding strap unit but leave it still legible and write part number “B851M2061101” close to the old P/N (see Figure 1). Protect identification with laquer, single-layer (CM 421). Let laquer, single-layer dry IAW manufacturer’s instruction. (c) Reassemble the hook assembly as follows: NOTE The hook mount (4, Figure 1) and the damper housing (1) are a serialized matched set. 1 Push the bonding strap unit (2) together with the hook (5) and the hook mount (4) inside the damper housing (1). 2 Ensure that the tips of the bonding straps (1, Figure 7) are placed over the bonding probe (2) inside the damper housing (3). 3 Screw the hook (5, Figure 1) together with the hook mount (4) and the attached bonding strap unit (2) into the damper housing (1). 4 Install the lock spring (3) at the hook mount (4). 

## APPENDIX

PAGE 1 of 7ASB MBB-BK117 C-2-85A-041

Revision 2 (d) Replace the retaining ring in the shock attenuator as follows: NOTE To get better access reel out the hoist cable approx. 2 meters. 1 Remove the lock spring (3, Figure 8) from the shock attenuator (2). 2 Unscrew the shock attenuator (2) from the damper housing (1). NOTE The shock attenuator (2, Figure 8) and the damper housing (1) are a serialized matched set. 3 Remove the retaining ring (3, Figure 9) and discard. 4 Install the new retaining ring (4) in the groove (2) of the shock attenuator (1). 5 Push the shock attenuator (2, Figure 8) inside the damper housing (1). 6 Ensure that the tips of the bonding straps (3, Figure 10) are placed over the bonding probe (1) inside the damper housing (2). 7 Screw the shock attenuator (2, Figure 8) into the damper housing (1). 8 Install the lock spring (3) in the shock attenuator (2). 

## APPENDIX

PAGE 2 of 7ASB MBB-BK117 C-2-85A-041

Revision 2 Removal -- Bonding strap Figure 1 1 Damper housing 2 Bonding strap unit 3 Lock spring 4 Hook mount 5 Hook 1

2 3

Round off corners at the end of each bonding strap leg. 4

5 Identify with “B851M2061101”. 

## APPENDIX

PAGE 3 of 7ASB MBB-BK117 C-2-85A-041

Revision 2 Self--made -- radius gauge Figure 2 Sheet metal

6.4 mm diameter Cut after drilling

Self--made radius gauge Figure 3 

## APPENDIX

PAGE 4 of 7ASB MBB-BK117 C-2-85A-041

Revision 2 Bonding strap before modification Figure 4

Bonding strap after modification Figure 5 Round off the corners at the end of each bonding strap leg. Be careful to only round off the corners without shortening the total length of the bonding strap legs. 

## APPENDIX

PAGE 5 of 7ASB MBB-BK117 C-2-85A-041

Revision 2

1 Bonding strap 2 Bonding probe 3 Damper housing Reworked bonding strap Figure 6 Deburr and round off all edges of the reworked bonding strap ends.

Reassembly -- Hook assembly Figure 7 1

3 2 

## APPENDIX

PAGE 6 of 7ASB MBB-BK117 C-2-85A-041

Revision 2 Installation -- Retaining ring Figure 9 2 1

1 3

1 2 3 Removal -- Shock attenuator Figure 8 Identify with “EASB-85A-041 Rev 2”. 1 Damper housing 2 Shock attenuator 3 Lock spring

1 Shock attenuator 2 Groove 3 Old retaining ring VH--75--S02 4 New retaining ring M2742630109D or AS3217--109 2 3

1 4 2 

## APPENDIX

PAGE 7 of 7