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### WYTWORNIA



### SPRZ~TU KOMUNIKACYJNEGO ,,PZL-SWIDNIK" SPOLKAAKCYJNA Al. Lotnik6w Polskich 1 21-045 Swidnik, Poland Tel. (+48 81) 468 09 01, 751 20 71 Fax (+48 81) 468 09 19,751 21 73 Authorization/Certificate EASA: EASA. 21J.114

The contents ofthis Bulletin has been approved by Transportation Equipment FactoryPZL Swidnik S.A. under DOANo. EASA. 21J.114.



# TECHNICAL BULLETIN No. BT-37-07-196

NAME-TYPE/MODEL: PZLW-3A Helicopters I 

### PZL W-3A model SERIAL NUMBER: All SUBJECT: 

### 1. INSTALLATION OF CHECK VALVES IN THE GROUND PRESSURE LINE OF HYDRAULIC SYSTEM 

### 1 AND 2 SUBSYSTEMS 2. OPERATION SPECIFICATION UPDATE

The original Bulletin in Polish language was approved on 24.04.2007. The English translation ofthe original was approved by the Manufacturer under delegated authority ofULC. Agnieszka Siedlecka GILC-Authorized InterpreterI This is to inform the PZLW-3A/Model PZLW-3Ausers that PZL-Swidnik S.A. has designed and launched a serial production ofthe check valves 37.59.336.00.00 intended for installation in the ground pressure line ofsubsystems 1 and 2 ofthe hydraulic systemin accordance with the drawing 37.59.330.00.00. The valves are used to prevent the hydraulic fluid leakage from both the subsystems when any ofthe hoses installed between the hydraulic blocks and the ground supplyboard gets damaged. After the installation ofthe valves 37.59.336.00.00 on the helicopter, the provisions ofthe ObligatoryBulletin B0-37-07-192 shall cease to be valid. The said Bulletinrecommended disconnecting the hose 37.59.234.00.00 and thepipe 37.59.233.00.00installed in the ground pressure line ofthe Subsystems 1 and 2 from the hydraulic blockfittings. II In order to install the valves onthe helicopters in operation, remove the pipe 37.59.233.00.00 and the hose 37.59.234.00.00 connecting the hydraulic blocks pressure lines with the elbows onthe upper deck and replace them with the check valves 37.59.336.00.00 and the pipe 37.59.333.00.00 and the hose 37.59.334.00.00. The valves shallbe installed in accordance with Sketch 1 and the following procedure: 1) Drain the fluid from the reservoirs ofbothhydraulic blocks as per the Operation Sheet 29.00-2 ofthe Maintenance Manual. 2) Remove the hoses 37.59.233.00.00 and 37.59.234.00.00. 3) Install check valves 37.59.336.00.00. onthe hydraulic blocks ground pressure line fittings ofthe Subsystems 1 and 2. Set the valves so the axes ofthe sockets where the hoses are connected match the axes ofthe hose fittings. 4) Fit the hose 37.59.334.00.00 (Subsystem 1) and the pipe 37.59.333.00.00 (Subsystem 2) betweenthe fittings ofthe installed check valves and the elbow connectors onthe upper deck. Follow the procedure laid down in Subchapter 29.00.00 ofthe Maintenance Manual and the notes specified below. 5) Use clips to fix the hose to the hydraulic blockbase tubes. 6) Lockwire the screwjoints. 7) Fill the helicopter hydraulic systemwith the working fluid as per Operation Sheet 29.00-2, wash the system as per Operation Sheet 29.00-4 and check the hydraulic system operation as per Operation Sheet 29.00-3. Notes: 1) Keep a proper cleanness while installing the hose and do not perform any activities that may produce dust or chips. Seals and plugs ofthe hoses shallbe removed directlybefore the hoses are connected. 2) The screwjoints shall be screwed together using the hydraulic oilused in the system. 3) Prior to the installation ofthe hose, check the following: a) Properplacement ofthe hose (proper shape), b) Alignment (degree ofthe axis dislocation) ofthehose fitting relative to the cone ofthe component onto which the hose is to be installed. The axis dislocation when the hose is not fitted shall not exceed 0,5d (the hose inner diameter) along 50d from the hose connectionpoint and shall vary in proportion to the change in the distance between the hose fitting and the connectionpoint.

2/6 BT-37-07-196c) Alignment ofthe mating cones ofthe hose and connector in the connectionpoints. The alignment ofthe cones shall be checkedbytightening the hose nut. The nuts shouldbe screwed finger-tight easily along 2/3 ofthe thread length. 4) To ensure proper alignment ofthe hose cones with the cones ofthe parts/products fittings to which the hose is connected, it is allowable to fit the hose previouslyremoved from the helicopter by bending the pipe smoothly (causing no folds or excess bends) in the curvature area. Over-bending the pipe and its deformations within 10 mm from the edge ofthe fitting are not acceptable. The hose section cannot be flattened in the overbend area bymore than 15% ofits outer diameter.
III List ofparts required for accomplishment ofthis Bulletin Item Nomenclature Drawing, Specification, Type Quantity I Notes rotor 1. Hose 37.59.333.00.00 1 2. Hose 37.59.334.00.00 1 3. Checkvalve 37.59.336.00.00 2 4. Clip 1666s50-8-R 1 5. Clip 1666s50-16-R 1 6. Clip 1666s50-18-R 1 7. Clip 1672s52-8-I-N 1 8. Screw 3166A-5-10 2 9. Nut 3373A-5 2 10. Washer 5,3x8x0,8- 20ZnC BN-7711118-01 2 11. Lock wire pb- 

### II- Na <!> = 0,8 1= 1m

-- IV The check valves shallbe installed onthe helicopters in operation bythe User's authorized maintenance facility personnel. The installation may also be performed byPZL-Swidnik S.A. as part of a separate order ofthe User and at the User's expense. The parts required for the accomplishment ofthis Bulletin shall be suppliedby PZL-Swidnik S.A. at the User's request and expense. 

## v 1) Chapter 29 ofthe W-3A Helicopter Maintenance Manual, Doc. No. AE 30.04.20.1 lOT (in Polish) and AE 30.04.20.1 MM (in English) shallbe revised to include the provisions ofRevision 5 (March 2007). In order to revise the Chapter, the following pages ofthe Manual shall be replaced:

- Page 1 in the List ofEffective Pages;

- Pages 2,4 and 5 in Subchapter 29.00.00;

- Pages 2 and 4 in Subchapter 29.02.00;

- Pages 6,7,8,9 in Subchapter 29.10.00;

- Pages 8, 9 in Subchapter 29.12.00.

BT-37-07-196 3/62) After installing the valves in the helicopter, enter the following statement in the Log Book: Checkvalves 37.59.336.00.00 have beeninstalled in the ground pressurelines ofthehydraulic system. As evidence that the valves installation has been completed, enter the Bulletin reference number and the installation date in the Log Book. The record shall be finally confirmed with a stamp and signature ofthepersonperforming the installation.

4/6 BT-37-07-196

### Sketch 

### 1. Installation ofcheck valves 

## ,..KL

Upper deck plane



# --·---J-~. **=+=~~~~~~~~~~** Frame 14 plane

**~** 

### Hose 37.59.233.00.00 valve installation) Hose 37.59.333.00.00 (afire valve installation) Hose 37.59.234.00.00 valve· Hose 37.59.334.00.00 (after valve installation) 

## A 

## B 1666s50-8-R

1666s50-16-R

Washer 5 3x8x0

BT-37-07-196 

## ·I 5/6

### Sketch 1. continued 

# c

valve 37.59.336.00.00 Hose 37.59.334.00.00 Hose 37.59.333.00.00

6/6 BT-37-07-196