ALERT 

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BOLLETTINO TECNICO 

The technical content of this document is approved 

under the authority of DOA nr. EASA.21J.005. 

N° 412-133 

DATE May 17, 2012 

REV.

Compliance with 

this bulletin is: 

SUBJECT: HOIST HOOK ASSEMBLY P/N BL-5740-8, INSPECTION OF. 

REASON: To avoid loss of hoist hook assembly P/N BL-5740-8 installed on hoist P/N BL20200-75 (Breeze Eastern) and/or hoist P/N BL-20200-95 (Breeze Eastern). 

HELICOPTERS AFFECTED:

Agusta AB412 and AB412EP helicopters. 

 

COMPLIANCE:

Before next flight after receipt of this Bollettino, and subsequently every time the hook 

assembly is disassembled/reassembled. 

DESCRIPTION:

It is reported to Agusta a case of separation of Hook P/N HK-118-2. The investigation 

performed revealed that the nut P/N BL-10892 and housing hook P/N BL-9197 were not 

properly screwed (ref. Figure 1). In this condition the two locking screws were not inserted 

into the slot located on the housing. Due to the similarity between the locking systems used on 

Hook P/N HK-118-2 and Hook P/N BL-5740-8, installed on hoist P/N BL-20200-75 and/or 

hoist P/N BL-20200-95, this Bollettino provide the instructions to verify that the nut and body 

are properly screwed. 

MANDATORY

An appropriate entry should be made in the aircraft log book upon accomplishment.

If owner ship of air c raft has changed, please, forward to new owner.

AgustaWestland S.p.A

Via Giovanni Agusta, 520

21017 Cascina Costa di Samarate (VA) Italy

Tel.: +39 0331 229111 - Fax: +39 0331 229605/222595

ALERT

ALERT
B.T. 412-133

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MANPOWER REQUIRED: 

Approximately 0,5 man-hour is required to carry out the visual inspection. 

WARRANTY: N.A. 

MATERIAL REQUIRED: 

P/N DENOMINATION Q.TY

MS-24665-88 (*) Cotter pin 2 

Note: (*) Required only if it is necessary disassembly/reassembly the hook assembly 

SPECIAL TOOLS: N.A. 

WEIGHT AND BALANCE CHANGE: N.A. 

REFERENCES: 

AB412-IPC Illustrated Parts Catalogue 

AB412EP-IPC Illustrated Parts Catalogue 

AB412-MM Maintenance Manual 

TD-96-012 Breeze Eastern Operation and Maintenance Manual 

PUBBLICATIONS AFFECTED: 

AB412-MPM Maintenance Planning Manual 

ACCOMPLISHMENT INSTRUCTIONS:

1. Prepare helicopter for safe ground maintenance. 

2. Reel out cable from hoist as required to allow the maintenance of the hook. 

3. Disconnect battery and all the electric power source and/or the external power supply. 

4. Pull down the rubber bumper (10) to get the visual of the set screw in the slot as illustrated in 

Figure 2. 

a. If two screws (15) are inserted in the slots (ref. Figure 2), this indicates that nut and 

body are properly screwed. Check that rubber bumper (10) return in proper position. 

No other action is required, proceed in accordance with step 19. 

b. If two screws (15) are not inserted in the slots (ref. Figure 3), this indicates that nut and 

the body are not screwed. In this case proceed in accordance with following steps 5÷18. 

5. With reference Figure 4 separate the bumper assembly from the hook assembly. Pull bumper 

assembly from top of sleeve (13) then slide it up wire rope cable toward the hoist assembly. 

6. Remove cotter pins (16) and locking screws (15) from nut (14). 
B.T. 412-133

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7. While holding body (3), unthread nut (14), remove bottom half of hook assembly and rubber 

bumper (10). Slide nut (14) and sleeve (13) up wire rope cable away from the ball end to 

expose terminal clamp (11). 

8. Remove ring (18) from terminal clamp (11) and then remove terminal clamp (11), sleeve (13) 

and nut (14). 

9. With reference Figure 4 and 5 reinstall nut (14), sleeve (13) with terminal clamp (11), onto 

ball end of hoist cable, and secure terminal clamp with ring (18). 

10. Slide sleeve (13) and nut (14) down until terminal clamp (11) seats in sleeve (13). In 

accordance with Figure 5 verify that terminal clamp (11) and ring (18) are correctly seats in 

sleeve (13). 

11. Install rubber bumper onto body (3). Thread body (3) with bottom half of hook assembly onto 

nut (14), until bottomed. 

12. Back off nut (14) to line holes with next nearest slots in body (3). Insert locking screws (15) 

and screw home to bottom of slot in body (3), and then secure locking screw in place with 

new cotter pins (16) P/N MS-24665-88. 

13. Slide bumper assembly down and seats in sleeve (13). 

14. Restore the power to the hoist, and proceed in accordance with following steps. 

15. Run hoist to slowly pay out cable until the hook can be connected to a weight of 272 Kg. 

16. Connect load to hook and slowly reel cable in until the weight is lifted off the ground 

17. Once weight is off the ground, lower weight back to the ground and remove the weight. 

18. Pull down the rubber bumper (10) to get visual of the set screw in the slot as illustrated in 

Figure 2. 

a. If two screws (15) are inserted in the slots (ref. Figure 2), this indicates that nut and 

body are properly screwed. Check that rubber bumper (10) return in proper position. 

No other action is required, proceed in accordance with step 20. 

b. If two screws (15) are not inserted in the slots (ref. Figure 3), this indicates that nut and 

the body are not screwed, in this case disconnect the power to the hoist, and repeat steps 

5÷18. 

19. Reconnect battery and all the electric power source and/or the external power supply. 

20. Run hoist to the full in position to secure to hook and bumper assembly on hoist. 

21. Return the helicopter to flight status and annotate records to indicate compliance with this 

Bollettino. 
B.T. 412-133

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Figure 1 – HK-118-2 Hook assembly (For reference only) 

NUT P/N BL-10892 

HOUSING HOOK 

P/N BL-9197 
B.T. 412-133

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Figure 2 – Detail of Hook assembly P/N BL-5740-8 

This condition indicated that nut and body are screwed. 

The locking screws P/N BL-9920 are properly inserted in the slot. 

SCREW INSERTED 

IN THE SLOT 

NUT (14) 

BODY (3) 

RUBBER BUMPER (10) 
B.T. 412-133

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Figure 3 – Detail of hook assembly P/N BL-5740-8 (Cotter pin omitted) 

This condition indicated that nut and body are not screwed 

Locking screws P/N BL-9920 not inserted in the slot. 

SCREW NOT INSERTED 

IN THE SLOT 

NUT (14) 

BODY (3) 
B.T. 412-133

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NOTE: Bumper assembly not illustrated 

Figure 4 – BL-5740-8 Hook assembly 

WIRE ROPE ASSEMBLY

SWIVEL HOOK (1)

SPACER (17)

BODY (3)

WASHER (4)

BEARING (5)

WASHER (19)

RUBBER BUMPER (10)

SCREW (15)

COTTER PIN (16)

TERMINAL CLAMP (11)

RETAINING RING (18) 

LABEL (12)

NUT (14) 

PIN-SPRING (9)

NUT (8)

PACKING (6) 

RETAINER BEARING (7)

SLEEVE (13)

BEARING (2)
B.T. 412-133

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Figure 5 – Detail of terminal clamp installation 

HOIST CABLE 

SLEEVE (13) 

RING (18) 

TERMINAL CLAMP (11) 
Note: 

Remarks:

Informazioni: 

Information:

Al fine di gestire le varianti alla configurazione base, in relazione all’emissione del Bollettino Tecnico, preghiamo di voler compilare il presente modulo in tutte le sue parti e spedirlo all’indirizzo sopra indicato. Si ringrazia per la gentile collaborazione data. 

We request your cooperation in filling this form, in order to keep out statistical data relevant to aircraft configuration up-to-date. The form should be filled in all 

its parts and sent to the above address. We thank you beforehand for the information given.

MODULO APPLICAZIONE BOLLETTINO TECNICO

TECHNICAL BULLETIN COMPLIANCE FORM

Data: 

Date:

Numero: 

Number:

Revisione: 

Revision:

Prego spedire a questo indirizzo: 

Please send to the following address: 

AGUSTAWESTLAND S.p.A. 

CUSTOMER SUPPORT & SERVICES - ITALY

PRODUCT SUPPORT ENGINEERING DPT.

Via del Gregge, 100

21015 Lonate Pozzolo (VA) - ITALY 

Tel.: +39 0331 664905

Fax: +39 0331 664684

Telefono: 

Telephone:

Fax:

Data Applicazione B.T.: 

B.T. Compliance Date:

Denominazione Cliente ed Indirizzo: 

Customer Name and Address:

Modello Elicottero 

Helicopter Model S/N Matricola Tail Number

Ore Totali 

Total Hours

Ore D.U.R. 

T.S.O.