Service Bulletin No: 53-008 Ref No: 148 Modification No: Inspection ATA Chapter: 53 SERVICE BULLETIN

PILATUS AIRCRAFT LTD. STANS, SWITZERLAND

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 1 of 18 FUSELAGE - GENERAL DO A CHECK OF THE MATERIAL SPECIFICATION USED IN THE MANUFACTURE OF THE ENGINE MOUNT FITTINGS AND, IF NECESSARY, DO A CHECK FOR CRACKS WITH A BOROSCOPE 1. Planning Information A. Effectivity PC-7 aircraft MSN 101 thru MSN 618. All engine mount fittings (P/N 112.35. 07.152) held as spare or in stock. B. Concurrent Requirements None. C. Reason (1) Problem An operator reported Stress Corrosion Cracking (SCC) on the engine mount fittings. (2) Cause Initially the material specification of the pa rts was AA2024-T351. The material specification was subsequently changed to AA2124-T851 to decrease the risk of stress corrosion. NOTE: Some customers Structural Repair Manual (SRM) can identify the engine mounting-frame attachment-fittings as made from SNV-L748.5. This is an equivalent to AA2024-T351. (3) Solution Do a one time inspection of the four engine mount fittings to: (a) Check the material specification of the fittings. (b) If the fittings are made from AA2124-T851, make an entry in the aircraft logbook as required in paragraph 3.F.(3). (c) If the fittings are made from AA2024-T351, do a one time inspection with a boroscope for cracks. (d) If cracks are fou nd, contact Pilatus. NOTE: Mandatory inspections will be added to Chapter 5 of the Aircraft Maintenance Manual (AMM). The inspections will gi ve instructions on how to examine the four engi ne mount fittings for cr acks. The inspections will only be applicable to parts made from AA2024-T351.Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 2 of 18 SERVICE BULLETIN

NOTE: A Service Bulletin will be issued to give instructions and data on how to replace the parts made from AA2024-T351. The new parts are made from AA2124-T851. Parts that are replaced with those made from AA2124- T851 will cancel the requ irement for the mandator y repetitive inspections. D. Description This Service Bulletin gives the data and instructions necessary to: (1) Check the material specification of the fittings. (2) If the fittings are made from AA2124-T851, make an entry in the aircraft logbook of the new part number. (3) If the fittings are made from AA2024-T351, do a one time inspection with a boroscope for cracks. These instructions are applicable to the left and right, upper and lower, engine mount fittings, P/N 112.35.07.152. E. Compliance Mandatory. Accomplishment required not later than 90 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 Operators/Owners to check with th eir delegated Airworthiness Authorities for any changes, local regulations or sanctions that may affect the embodiment of this 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.SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 3 of 18 H. Manpower

I. Weight and Balance (1) Weight Change Not changed. (2) Moment Change Not changed. J. Electrical Load Data Not changed. K. Software Not changed. L. References Aircraft Maintenance Manual (AMM ): 12-00-00, 20-31-00, 25-10-00. M. Publications Affected AMM, Chapter 05. Structural Repair Manual (SRM): 53-10-00. N. Interchangeability of Parts Not applicable. Total Preparation 2.0 Eddy-current conductivi ty measurement-test 0.5 Boroscope inspection (If Necessary) 2.0 Close up 2.5 TOTAL MAN-HOURS 7.0Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 4 of 18 SERVICE BULLETIN

2. Material Information

Operators who require more information should contact: PILATUS AIRCRAFT LTD, INTEGRATED LOGISTIC SUPPORT MANAGER, CH 6371 STANS, Tel: +41 41 619 66 30 SWITZERLAND Fax: +41 41 610 33 51 A. Material - Price and Availability

NOTE: Kit No. 500.60.09.146 is the kit for the re ference pieces used to help identify the material specification of the suspect parts. O ne kit is required for each fleet of aircraft. B. Material Necessary for Each Aircraft (1) Material to be Procured Kit No. 500.60.09.146 has these parts:

NOTE: One kit is required for each fleet of aircraft. (2) Operator Supplied Materials (Ref. AMM 20-31-00)

C. Material Necessary for Each Spare None. D. Re-identified Parts If the engine mount fittings, either installed on th e aircraft or held as spare, are made from AA2124-T851, their part nu mbers will change as follows: KIT NUMBER PRICE AVAILABILITY 500.60.09.146 Contact address above Contact address above

PART No. DESCRIPTION QTY REMARKS 513.57.09.149 AA2024-T351 REFERENCE PLATE 1 513.57.09.150 AA2124-T851 REFERENCE PLATE 1

MATERIAL NO. DESCRIPTION QTY REMARKS P01-010 SOLVENT A/R Or equivalent P02-031 ABSORBENT PAPER A/R Or equivalent

DESCRIPTION OLD PART NUMBER RE-IDENTIFIED PART NUMBER ENGINE MOUNT FITTING 112. 35.07.152 553.10.07.033SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 5 of 18 E. Tooling - Cost and Availability

NOTE: Because of the difficult access, Pilatus recommends that the maximum diameter of the measurement probe is 6,25 mm (0.25 in.). PART No. DESCRIPTION QTY REMARKS - EDDY-CURRENT EQUIPMENT WITH CONDUCTIVITY MEASUREMENT PROBE 1 Local supply

OR - CONDUCTIVITY MEASUREMENT EQUIPMENT 1 Local supply - BOROSCOPE 1 Local supply - ALUMINIUM OR STEEL TUBE OF APPROXIMATELY 800 MM LENGTH X 10 MM DIAMETER 1 Local supplyService Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 6 of 18 SERVICE BULLETIN

3. Accomplishment Instructions - On Aircraft WARNING: READ AND OBEY THE MANUFACTURERS H EALTH INSTRUCTIONS BEFORE YOU USE THE CONSUMABLE MATERIALS. A. Preparation (1) Remove the access panel F5 (Ref. AMM, 12-00-00, Page Block 1). (2) Remove the seat from the front cockpit (Ref. AMM, 25-10-00, Page Block 201). (3) Obey the manufacturer’s operating inst ructions and calibrate the conductivity measurement equipment. (4) Put the eddy current probe in position on the reference plates (P/N 513.57.09.149 and P/N 513.57.09.150). (5) Record the value shown on the test equipment. NOTE: The temperature of the left and right, upp er and lower, engine mount fittings (P/N 112.35.07.152) and the reference plates (P/N 513.57.09.149 and P/N 513.57.09.150) must be approximately the same. B. Do the Test to Find the Mate rial Specification (Ref. Fig. 1) NOTE: Only personnel that are qua lified and authorized by their delegated Airworthiness Authorities are allow ed to do this test. NOTE: Because of the access, Pilatus recommends that the conductivity probe has a maximum diameter of approximately 6.25 mm (0.25 in.). (1) For the left upper engine-mount atta chment-fitting (1) (P/N 112.35.07.152): WARNING: BE CAREFUL WHEN YOU USE THE CONSUMABLE MATERIALS. OBEY THE MANUFACTURER‘S HEALTH AND SAFETY INSTRUCTIONS. (a) Remove the dirt and grease from the test area with the absorbent paper (Material No. P02-031) made moist with the solvent (Material No. P01-010). NOTE: It is not necessary to remove the layers of surface protection (including paint) to do the test. NOTE: The temperature of the engine mount fi ttings (P/N 112.35.07.152) and the reference plates (P/N 513.57.09. 149 and P/N 513.57.09.150) must be approximately the same. (b) Put the eddy current probe in position on the left upper engine-mount attachmentfitting (1) (P/N 112.35.07.152). (c) Record the value shown on the test equipment. (d) Compare the value recorded above with the values recorded in Section 3.A.(5) and determine if the attachment fitting is manufactured from AA2024-T351 or AA2124- T851. (e) Do Steps 3.B(1)(b) thru (d) again to make sure the result is the same.SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 7 of 18 (f) Write the type of material that the le ft upper engine-mount attachment-fitting (1) (P/N 112.35.07.152) is made from on the Status of Parts Form (Ref. Fig 5). (2) Do Step 3.B.(1) of this Service Bulletin again on the right upper and left and right lower, engine mount fittings (P/N 112.35.07.152). (3) If you find an engine mount fitting made fr om AA2024-T351, continue this Service Bulletin from Step 3.C. (4) If all the engine mount fittings are made from AA2124-T851, continue this Service Bulletin from Step 3.D. C. Do the Boroscope Inspection to Find Cracks (Ref. Fig. 2) NOTE: Step 3.C. is only applicable to engine mount fittings made from AA2024-T351. NOTE: Only personnel that are qualified and authorized by their delegated Airworthiness Authorities are allowed to do this test. (1) Obey the manufacturer’s instructions and use a boroscope to examine the areas shown in Fig. 2: (a) Use the aluminium or steel tube as a guide for the boroscope to access the inspection areas. (b) If you find cracks: 1 You must contact Pilatus Customer Support before next flight. The address is: PILATUS AIRCRAFT LTD., Customer Technical Support (MCC), P.O. Box 992 6371 Stans, Switzerland Fax: + 41 (0)41 619 67 73 Email: Techsupport@pilatus-aircraft.com 2 Make a report of the inspection results, refer Step 3.D. (c) If you do not find cracks, make a report of the inspection results, refer Step 3.D.Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 8 of 18 SERVICE BULLETIN

D. Report the Inspection Results (1) Make a copy of the Inspection Repo rt Form(s) (Ref. Fig. 3 and Fig. 4). (2) Complete the Inspection Report Form(s): • Give the date of the inspection. • Give the aircraft details. • Show the location(s) and dimensions of the crack(s) found (if applicable). • Add any comments. NOTE: If there are no crack indications, use t he Inspection Report Form(s) to tell Pilatus Aircraft Ltd the aircraft details. (3) Add the part number of the engine mount fittings to the final column of the Status of Parts Form (Ref. Fig. 5). NOTE: If the engine mount fittings are made from AA2024-T351, t he part number will be the same as that entered in column 3. If the engine mount fittings are made from AA2124-T851, the part number will change as shown in Para. 2.D. (4) Send or fax the completed form(s) and a copy of the Status of Parts Form (Ref. Fig. 5) to Pilatus Customer Support. E. Job Close-Up (1) Remove all equipment, materials and tools from the work area. Make sure that the work area is clean. (2) Install the seat in the front cockpit (Ref. AMM, 25-10-00, Page Block 201). (3) Install the access panel F5 (Ref. AMM, 12-00-00, Page Block 1). F. Documentation (1) Make an entry in the Aircraft Logbook that this 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. (3) Put the Status of Parts Form (Ref. Fig 5) in the Aircraft Logbook. NOTE: If the engine mount fittings are made from AA2024-T351 but have no cracks, you will need to do repetitive inspections (R ef. AMM, Chapter 05 ). You will need this Form (Ref. Fig. 5) to tell you which engine mount fittings require the inspection.SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 9 of 18 4. Accomplishment Instructions - Engine Mount Fittings Held as Spare or in Stock NOTE: This procedure is applicable to all engine mount fittings (P/N 112.35.07. 152) held as spare or in stock. A. Preparation (1) Obey the manufacturer’s operating inst ructions and calibra te the conductivity measurement equipment. (2) Put the eddy current probe in position on the reference plates (P/N 513.57.09.149 and P/N 513.57.09.150). (3) Record the value shown on the test equipment. NOTE: The temperature of the engine mount fi ttings (P/N 112.35.07.152) and the reference plates (P/N 513.57.09. 149 and P/N 513.57.09.150) must be approximately the same. B. Do the Test to Find the Material Specification NOTE: Only personnel that are qualified and authorized by their delegated Airworthiness Authorities are allowed to do this test. (1) For each engine mount fitting (P/N 112.35.07.152): WARNING: BE CAREFUL WHEN YOU USE THE CONSUMABLE MATERIALS. OBEY THE MANUFACTURER‘S HEALTH AND SAFETY INSTRUCTIONS. (a) Remove the grease from the test area with the absorbent paper (Material No. P02-031) made moist with the solvent (Material No. P01-010). NOTE: It is not necessary to remove the laye rs of surface protection (including paint) to do the test. (b) Put the eddy current probe in position on the engine mount fitting (P/N 112.35.07.152). (c) Record the value shown on the test equipment. (d) Compare the value recorded above with the values recorded in Section 4.A.(3) and determine if the engine mount fitting (P/N 112.35.07.152) is made from AA2024- T351 or AA2124-T851. (e) Do Steps 4.B(1)(b) thru (d) again to make sure the result is the same. (f) If the engine mount fitting (P/N 112.35. 07.152) is made from AA2024-T351, send it to Pilatus Customer Suppor t. Pilatus will send a replac ement engine mount fitting (P/N 553.10.07.032) made from AA2124-T851.(g) If the engine mount fitting (P/N 112.35.07.152) is made from AA2124-T851, reidentify the fitting (Ref. Para. 2.D.) wit h a permanent marker pen (or equivalent).Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 10 of 18 SERVICE BULLETIN

C. Job Close-Up (1) Return the engine mount fittings to stores. (2) Make sure the part number is correct and ei ther P/N 553.10.07.033 (Re-identified) or P/N 553.10.07.032 (New). D. Documentation (1) Make an entry on the serviceable label (att ached to the engine mount fitting) that this Service Bulletin has been incorporated. (2) Use the Service Bulletin Evaluation Shee t and report your results to Pilatus.SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 11 of 18 Check of the Material Specification Figure 1 

# A

FRAME 1



# A FRAME 1 

# B

C C



# C B
LH SHOWN RH SIMILAR
1

LH SHOWN RH SIMILAR 

# B

2SB 2198Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 12 of 18 SERVICE BULLETIN

Fittings - Crack Insp ection (If Necessary) Figure 2 

# A

FRAME 1



# A FRAME 1 

# B

C C



# C B
LH SHOWN RH SIMILAR

LH SHOWN RH SIMILAR 

# BSB 2199 CRACK INSPECTION AREA (INSPECT BOTH FLANGES) CRACK INSPECTION AREA (INSPECT BOTH FLANGES)SERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 13 of 18 Upper Fittings - Inspection Form Figure 3SB 2200 RH UPPER FITTING DATE: AIRCRAFT MSN: FLYING HOURS: LANDINGS:
ADDITIONAL COMMENTS CRACK 1 LENGTH mm CRACK 2 LENGTH CRACK 3 LENGTH CRACK 4 LENGTH mm

mm
mm LH UPPER FITTING DATE: AIRCRAFT MSN: FLYING HOURS: LANDINGS:
ADDITIONAL COMMENTS CRACK 1 LENGTH mm CRACK 2 LENGTH CRACK 3 LENGTH CRACK 4 LENGTH mm

mm
mmService Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 14 of 18 SERVICE BULLETIN

Lower Fittings - Inspection Form Figure 4SB 2201 RH LOWER FITTING DATE: AIRCRAFT MSN: FLYING HOURS: LANDINGS:
ADDITIONAL COMMENTS CRACK 1 LENGTH mm CRACK 2 LENGTH CRACK 3 LENGTH CRACK 4 LENGTH mm

mm
mm LH LOWER FITTING DATE: AIRCRAFT MSN: FLYING HOURS: LANDINGS:
ADDITIONAL COMMENTS CRACK 1 LENGTH mm CRACK 2 LENGTH CRACK 3 LENGTH CRACK 4 LENGTH mm

mm
mmSERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 15 of 18 Status of Parts Form Figure 5Line No.ComponentPart NumberMaterial Specification, afteraccomplishment of this Service BulletinPart Number, after accomplishmentof this Service Bulletin1The engine upper-mount fitting, LH112.35.07.1522The engine upper-mount fitting,RH112.35.07.1523The engine lower-mount fitting, LH112.35.07.1524The engine lower-mount fitting, RH112.35.07.152Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 16 of 18 SERVICE BULLETIN

INTENTIONALLY BLANKSERVICE BULLETIN

Service Bulletin No: 53-008 Date: Nov 30/12 Rev. No. Date: Page 17 of 18



## SERVICE BULLETIN EVALUATION SHEET FOR SB No. 53-008 Title Fuselage - General - Do a Check of the Material Specification Used in the Manufacture of the E ngine Mount Fitt ings and, If Necessary, Do a Check for Cracks with a Boroscope 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: 53-008 Date: Nov 30/12 Rev. No. Date: Page 18 of 18 SERVICE BULLETIN

INTENTIONALLY BLANK