Service Bulletin No: 21-012 Ref No: 165 Modification No: EC-14-0359 ATA Chapter: 21 SERVICE BULLETIN

PILATUS AIRCRAFT LTD. STANS, SWITZERLAND

Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 1 of 10 AIR CONDITIONING - COOLING INSTALL A COVER ASSEMBLY TO THE COMPRESSO R TO PROTECT TO THE ENGINE OIL HOSE 1. Planning Information A. Effectivity MSN 101 thru 607, Pre Service Bulletin 21-006. B. Concurrent Requirements None. C. Reason (1) Problem On PC-7 aircraft that are pre Service Bulletin 21-006, the oil cooler inlet-hose is routed close to the air conditioning compressor clutch plate. If a spring on the compressor clutch plate shears, the oil hose can become damaged and the engine oil can spill into the engine bay. (2) Solution Install a cover assy which will be mounted on the attachment pointsof the compressor. This will provide a barrier between the comp ressor clutch plate and the oil hose. The shield can be mounted on the compressor support bracket with the current bolts. D. Description This Service Bulletin gives the data and instructio ns necessary to insta ll a cover assy (between the compressor clutch plate and the oil hose) to protect the oil hose. E. Compliance Mandatory. Accomplishment required not later than 120 days afte r the effective date of this Service Bulletin. F. Approval The technical content of this Se rvice Bulletin is approved under the authority of Letter of DOA Acceptance ref. FOCA.21J.002. Pilatus advises Oper ators/Owners to check with their designated Airworthiness Authorities for any changes, local regulations or sanctions thatmay affect the embodiment of this Service Bulletin.Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 2 of 10 SERVICE BULLETIN

G. Copyright Information © Pilatus Aircraft Ltd. This document contains proprietary information that is protected by copyright. All rights are reserved. No part of this document may be copied, reproduced or translated to other languages without the prior written consent of Pilatus Aircraft Ltd. H. Manpower

NOTE : Man-hours figures do not include the time required to cure sealants, paints and adhesives. I. Weight and Balance (1) Weight Change Negligible. (2) Moment Change Negligible. J. Electrical Load Data Not changed. K. Software Not changed. L. References Aircraft Maintenance Manual (AMM): 12-00-00, 20-31-00, 21-50-00. M. Publications Affected Aircraft Parts Catalog (IPC): 21-10-01. N. Interchangeability of Parts Not applicable. Total Total Preparation 1.0 1.0 Installation of the Cover Assy 0.5 0.5 Close up 1.5 Close up (including, if necessary, to evacuate and charge the cooling system) 4.5
TOTAL MAN-HOURS 3.0 6.0SERVICE BULLETIN

Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 3 of 10 2. Material Information
Operators who require fu rther information on Price and Av ailability should contact their Customer Liaison Manager at: Pilatus Aircraft Ltd, 6371 Stans, Switzerland. Operators are requested to advise Pilatus AircraftLtd. of the Manufacturer’s Serial Number (MSN), the flying hours and landings of aircraft which are allocated for this Service Bulletin using the Service Bulletin Evaluation Form. A. Material - Price and Availability

B. Material Necessary for Each Aircraft (1) Material to be Procured Modification Kit No. 500.50 .07.045 has these parts:

NOTE: Part Numbers given in this Service Bullet in are correct at the time of approval. Pilatus Aircraft Ltd. reserves the right to change the part numbers as necessary. Part numbers of items delivered with the M odification Kit are correct when the kit is dispatched. This could lead to differ ences between those part numbers quoted in this Service Bulletin and the Modification Kit if parts are superseded. Operators are requested to check the IPC for delivered parts which differ from those listed in the Service Bulletin Materials Kit List. Modification Kit Number Price Availability 500.50.07.045 Contact address above Contact address above

NEW PART NO. DESCRIPTION OLD PART NO. QTY DISP. CODE FIG ITEM
938.75.11.311 WASHER 1 - 1 1 938.77.11.110 WASHER 1 - 1 5 521.50.07.022 COVER ASSY 1 - 1 11 971.32.51.105 CABLE TIE 2 - 1 12Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 4 of 10 SERVICE BULLETIN

(2) Operator Supplied Materials (Ref. AMM, 20-31-00):

C. Material Necessary for Each Spare Not applicable. D. Re-identified Parts None. E. Tooling - Cost and Availability Not applicable. MATERIAL NO. DESCRIPTION QTY REMARKS P01-010 SOLVENT A/R Or equivalent P02-013 ABRASIVE CLOTH A/R Or equivalent P02-014 ABRASIVE CLOTH A/R Or equivalent P02-031 ABSORBENT P APER A/R Or equivalent P07-021 ALODINE 1132 A/R Or equivalent P10-013 DINITROL AV40 A/R Or equivalentSERVICE BULLETIN

Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 5 of 10 3. Accomplishment Instructions WARNING: BEFORE YOU DO WORK ON THE COOLIN G SYSTEM, MAKE SURE YOU OBEY THE SAFETY PRECAUTIONS LISTED IN THE AMM, 21-50-00, PAGE BLOCK 201). WARNING: BE CAREFUL WHEN YOU USE THE CONSUMABLE MATERIALS. OBEY THE MANUFACTURERS HEALTH AND SAFETY INSTRUCTIONS. NOTE: Obey the manufacturer's instructions when you mix and use the consumable materials. A. Preparation (1) Open and install a safety clip to the circuit breaker: COOLING SYSTEM. (2) Open the access panel ENG 3L (Ref. AMM, 12-00-00, Page Block 1). B. Installation of the Cover Assy (Ref. Fig. 1) (1) Remove, and keep, the bolt (3), the spring wa sher (2) and, if installed, the washer (1). (2) Remove, and keep, the nut (9), the washer (10), the ground lead (7) and the screw (6). NOTE: On Pre Service Bulletin installations, the ground lead (7) is installed on the aft face of the plate (4) (opposite to that shown in Figure 1). The washer (5) is not installed. (3) Prepare the plate (4) for the new position of the ground lead (7): (a) Make a circular mark on the forward faceof the plate around the lower attachment hole, approximately 10 mm from the edge of the hole. (b) Use the abrasive cloth (Material No. P02-013 and P02-014) to remove the paint and primer to get bare metal in the area you marked. (c) Clean the bare metal area with the solvent (Material No. P01-010) and absorbent paper (Material No. P02-031). (d) Apply layers of the Alodine 1132 (Material No. P07-021) on the bare metal area and allow to dry. (4) Put the cable ties (12) through the holes in the cover assy (11) (P/N 521.50.07.022). (5) Put the cover assy (11) (P/N 521.50.07.022) in position on the aft face of the plate (4) and around the pulleys (8). (6) Put the spring washer (2) and, if necessary, the new washer (1) (P/N 938.75.11.311) on the bolt (3). (7) Loosely install the bolt (3), complete with the spring washer (2) and the washer (1). (8) Put the ground lead (7) and the washer (5) (P/N 938.77.11.110) on the screw (6). NOTE: On Post Service Bulletin in stallations, the ground lead (7) is installed on the forward face of the plate (4) (as shown in Figure 1).Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 6 of 10 SERVICE BULLETIN

(9) Install the screw (6), complete with the ground lead (7) and the washer (5) (P/N 938.77.11.110), the washer (10) and the nut (9). (10) Tighten the bolt (3). (11) Make sure there is no interference between the pulleys (8) and the new cover assy (11) (P/N 521.50.07.022). (12) Use the cable ties (12) to attach the cables (13) to the cover assy (11) (P/N 521.50.07.022). (13) Apply a layer of Dinitrol AV40 (Material No. P10-013) to completely cover: • The screw (6) • The washer (5) (P/N 938.77.11.110) • The ground lead (7) • The bare metal of the plate (4) • The washer (10) • The nut (9). C. Job Close-Up (1) Remove all equipment, materials and tools from the work area. Make sure that the work area is clean. (2) Close the access panel ENG 3L (Ref. AMM, 12-00-00, Page Block 1). (3) Remove the safety clip and close the circuit breaker: COOLING SYSTEM. (4) If necessary, evacuate and charge the cooling system (Re f. AMM, 21-50-00, Page Block 301). (5) Do a test of the cooling system (Ref. AMM, 21-50-00, Page Block 501 ). During the system test, set the COOL switch to ON and OF F approximately 15 times at three second intervals. D. Documentation (1) Make an entry in the Aircraft Logbook thatthis Service Bulletin has been incorporated. (2) Use the Service Bulletin Evaluation Sheet and report your results and the serial number of the aircraft to Pilatus.SERVICE BULLETIN

Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 7 of 10 Installation of the Cover Assy Figure 1 1 

# A A

2 3 4 5

7

8

9 10 11 6

12 13 12Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 8 of 10 SERVICE BULLETIN

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Service Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 9 of 10



## SERVICE BULLETIN EVALUATION SHEET FOR SB No. 21-012 Title Air Conditioni ng - Cooling Install a Cover Assembly to the Compressor to Protect to the Engine Oil Hose Customer Service Center 

### EMBODIMENT REPORTING This SB has been embodied: On the entire fleet Only partially Provide embodiment details per aircraft (use additional copies of this table, if necessary) 

### MSN Flying Hours MSN Flying Hours

Additional embodiment comments/findings

EDITORIAL COMMENTS (procedure, kit quality, su ggested improvements, etc.)

Name Signature Date Please complete and forward this form to: Pilatus Aircraft LTD, Customer Technical Support (MCC), P.O. BOX 992, 6371 Stans, Switzerland Fax: +41 (0)41 619 6773 Email: Techsupport@ pilatus-aircraft.com 

### SERVICE BULLETIN EVALUATION SHEETService Bulletin No: 21-012 Date: Nov 04/14 Rev. No. Date: Page 10 of 10 SERVICE BULLETIN

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