SERVICE BULLETIN

SERVICE BULLETIN NO: 32-021 REF NO: 220

MODIFICATION NO: EC 08-0766 ATA CHAPTER: 32

DATE: Nov 21/08 SERVICE BULLETIN No. 32-021

REV No. PAGE 1 of 8

PILATUS AIRCRAFT LTD. CH-6371 STANS, SWITZERLAND

LANDING GEAR - NOSE WHEEL STEERING

REPLACEMENT OF THE CRANK BAR ASSY

1. Planning Information

A. Effectivity:

All PC-12 and PC-12/45 aircraft from MSN 101 thru MSN 299.

B. Concurrent Requirements

None.

C. Reason

(1) Problem

Failure of the nose wheel steering system because of fatigue cracking of the torque tube in 

the crank bar assy.

(2) Cause

Some torque tubes were bored off-center during manufacture. This results in a reduced 

wall thickness at one side of the torque tube. The torque tube can also crack at the bolt 

holes for the lever attachment bolt.

(3) Solution

Install a new crank bar assy which is manufactured to a higher standard.

D. Description

This Service Bulletin gives the data and instructions necessary to replace the crank bar assy.

E. Compliance

Mandatory.

At the next scheduled aircraft inspection.

F. Approval

The technical content of this Service Bulletin is approved under the authority of DOA No. EASA. 

21J. 357.

PILATUS advises Operators/Owners to check with their local Airworthiness Authorities for any 

changes, local regulations or sanctions that may affect the embodiment of this Service Bulletin.
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G. Manpower

H. Weight and Balance

(1) Weight Change

Not affected.

(2) Moment Change

Not affected.

I. Electrical Load Data

Not applicable.

J. Software

Not changed.

K. References

Aircraft Maintenance Manual (AMM): 12-A-07-10-00-00A-901A-A, 12-A-06-20-00-00A-040A-A, 

12-A-20-31-00A-070A-A, 12-A-32-50-00-00A-903A-A.

L. Publications Affected

Not applicable.

M. Interchangeability of Parts

A torque tube P/N 532.50.12.047 must not be installed on a Post SB 32-021 aircraft.

Man-hours

Removal 0.75

Installation 1.25

Test 0.50

Close Up 0.25

TOTAL MAN-HOURS 2.75
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2. Material Information

Operators should send orders for Service Bulletin Modification Kits, to their Authorized 

Pilatus Service Center or:

Operators are requested to advise Pilatus Aircraft Ltd, of the Manufacturer’s Serial 

Number (MSN) and the flying hours and landings of aircraft which are affected by this 

Service Bulletin.

PILATUS AIRCRAFT LTD.,

CUSTOMER SUPPORT MANAGER,

CH-6371 STANS,

SWITZERLAND

General Aviation:

Tel: + 41 41 619 6208

Fax: + 41 41 619 7311

eMail: SupportPC12@pilatus-aircaft.com

PILATUS BUSINESS AIRCRAFT LTD.,

PRODUCT SUPPORT DEPARTMENT

11755 AIRPORT WAY

BROOMFIELD, CO 80021.

UNITED STATES OF AMERICA

Tel: 303 465 9099

Fax: 303 465 6040

eMail: Productsupport@PilBal.com

PILATUS AUSTRALIA (PTY.) LTD,

17 JAMES SCHOFIELD DRIVE,

ADELAIDE AIRPORT SA 5950,

AUSTRALIA

Tel: (08) 8234 4433

Fax: (08) 8234 4499

Free Call: 1800 445 007

eMail: info@pilatus.com.au

A. Material - Price and Availability

B. Warranty

Credit will be issued for all affected aircraft on approval of a warranty claim, provided that:

• The work is done by an authorized service center during or before the next scheduled 

aircraft inspection but not later than 12 calendar months after the effective date of this 

Service Bulletin

• The removed parts are sent to Pilatus and receipt is confirmed.

C. Material Necessary for Each Aircraft

(1) Material to be Procured

Modification Kit No. 500.50.12.334 consists of these parts:

Modification Kit Number Price Availability 

500.50.12.334 Contact address above Contact address above

New Part No. Description Old Part No. Qty Disp. 

Code Fig Item

532.50.12.064 Torque Tube 532.50.12.047 1 R 1 20

Disposition Codes: D - Discard / R - Return to Pilatus
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(2) Operator Supplied Parts

(3) Operator Supplied Materials (Ref. AMM 12-A-20-31-00A-070A-A). 

D. Material Necessary for Each Spare

Not applicable.

E. Reidentified Parts

Not Applicable.

F. Tooling - Cost and Availability

Not Applicable.

532.50.12.051 Lever 532.50.12.051 1 R 1 12

932.19.60.801 Bolt, Hex, Cl Tol, Cres 

(AN174C13A)

932.19.60.801 1 D 1 1

938.77.11.114 Washer, Flat 

(NAS1149F0432P)

938.77.11.114 1 D 1 5

938.07.68.305 Nut, Hex, Slflkg

(MS21045-4E)

938.07.68.305 1 D 1 6

Part No. Description Qty Remarks

940.17.02.236 Pin, Cotter, Steel 1 MS24665-210

940.17.02.226 Pin, Cotter, Steel 2 MS24665-134

Material No. Description Qty Remarks

P01-008 Solvent A/R

P02-031 Absorbent Paper A/R

P04-012 Corrosion Preventative A/R

- Orcotape

(Pilatus P/N 917.40.61.113)

A/R If installed.

New Part No. Description Old Part No. Qty Disp. 

Code Fig Item

Disposition Codes: D - Discard / R - Return to Pilatus
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3. Accomplishment Instructions

A. Removal (Ref. Fig. 1)

(1) Lift the aircraft on jacks (Ref. AMM 12-A-07-10-00-00A-901A-A).

(2) Open and safety the circuit breaker:

HYDR CTL (NON ESSENTIAL BUS)

(3) Make sure the nose wheel is in the neutral position and there is no load on the spring strut 

(17).

(4) Open the access panel 11AL (Ref AMM.12-A-06-20-00-00A-040A-A).

(5) If necessary, remove the Orcotape and insulation to get access to the nut (4).

(6) Remove the cotter pin (7), the nut (8) and the washer (9).

(7) Remove the bolt (11) and disconnect the rod (10).

(8) Remove and discard the nut (6), the washer (5) and the bolt (1)

(9) Make sure that the lever (12) can turn on the torque tube (20). If you cannot turn the lever 

(12) with your hand:

(a) Lower the aircraft until the nose wheel is on the ground and cannot turn.

(b) Use force to make the lever (12) free to turn.

NOTE: You can use penetrating oil to help to release the lever.

(c) When you can turn the lever (12) on the torque tube (20), lift the nose wheel.

(10) Remove the cotter pin (15), the nut (14) and the washer (13).

(11) Remove the bolt (19) and disconnect the spring strut (17). Collect the washers (16) and 

(18).

(12) Remove the cotter pin (3), the nut (4) and the washer (2). Make a note of the installation 

position of the washer (2).

(13) Hold the lever (12) and remove the torque tube (20) from the lever and bearings.

(14) Keep the lever (12) and the torque tube (20) and send them to Pilatus Aircraft Ltd.

B. Installation (Ref. Fig. 1)

(1) Apply a thin layer of corrosion preventative (Material No. P04-012) to the inside mating 

surface of the lever (12)

(2) Hold the lever (12) (P/N 532.50.12.051) between the bearings and install the torque tube 

(20) (P/N 532.50.12.064). Make sure the lever (12) is installed in the correct position as 

shown in Fig. 1.

(3) Install the bolt (1) (P/N 932.19.60.801), the washer (5) (P/N 938.77.11.114) and the nut (6) 

(P/N 938.07.68.305).
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(4) Use the absorbent paper (Material No. P02-031) and the solvent (Material No. P01-008) to 

remove unwanted corrosion preventative from the torque tube (20).

(5) Install the washer (2) (in the position noted in the removal procedure), the nut (4) and the 

new cotter pin (3).

(6) Connect the spring strut (17) with the two washers (16) and (18) and the bolt (19).

(7) Install the washer (13), the nut (14) and the new cotter pin (15).

(8) Connect the rod (10) with the bolt (11).

(9) Install the washer (9), the nut (8) and the new cotter pin (7).

C. Test

(1) Do the adjustment/test of the nose wheel steering (Ref. AMM. 12-A-32-50-00-00A-903AA)

D. Close Up

(1) If necessary, install the insulation and the Orcotape.

(2) Close the access panel 11AL (Ref AMM. 12-A-06-20-00-00A-040A-A).

E. Documentation

Make an entry in the Aircraft Logbook that this Service Bulletin has been incorporated.
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 Crank Bar Assy - Removal/Installation

Figure 1

10

9

8

7

13

6

5

1

12

2

4

3

11

SB1801

A

B

B

A

14

16

17

18

19

20

15

THE NEW TORQUE TUBE

P/N 532.50.12.064

HAS NO GROOVE
DATE: Nov 21/08 SERVICE BULLETIN No. 32-021

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INTENTIONALLY BLANK