Service Bulletin No: 57-017

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Service Bulletin No: 57-017 Ref No: 183 Modification No: Inspection ATA Chapter: 57 SERVICE BULLETIN PILATUS AIRCRAFT LTD. STANS, SWITZERLAND Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 1 of 12 WINGS - WING STRUCTURE DO AN INSPECTION FOR CORROSION OF THE ANGLE BRACKETS INSTALLED ON THE LH AND RH WING MIDDLE RIB 23 1. Planning Information A. Effectivity MSN 101 thru MSN 618. B. Concurrent Requirements None. C. Reason (1) Problem An operator has reported that during a scheduled inspection corrosion was found on the angle brackets installed on the LH and RH wing middle rib 23. The angle brackets are made of steel and during manufacture of the wing, anchor nuts are installed on them. The anchor nuts are for the installation of the aileron outboard-bearing supports. Two types of anchor nuts were used, silver-plated or cadmium plated. It is possible that the silver-plated anchor nuts have caused the corrosion after being installed without corrosion preventative during manufacture of the wing. (2) Solution A borescope inspection is done for corrosion on the eight brackets installed on the LH and RH wing middle rib 23 around the area of the anchor nuts. The inspection will also identify what type of anchor nuts are installed, silver-plated or cadmium plated: If silver-plated anchor nuts are identified: • If corrosion is found on the brackets, the details of the corrosion will be reported to Pilatus • If corrosion is not found, mandatory inspections (added to Chapter 5 of the Aircraft Maintenance Manual (AMM)) become applicable. If cadmium-plated anchor nuts are identified: • If corrosion is found on the brackets, the details of the corrosion will be reported to Pilatus • If corrosion is not found, a layer of corrosion preventative will be applied to the brackets. Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 2 of 12 SERVICE BULLETIN D. Description This Service Bulletin gives the data and instructions necessary to: (1) Do the borescope inspection for corrosion on the eight brackets installed on the LH and RH wing middle rib 23 and identify the type of anchor nuts installed. (2) Do the recovery procedures dependent on the results of the borescope inspection. E. Compliance Mandatory. Accomplishment required not later than 12 months after the effective date of this Service Bulletin. F. Approval The technical content of this Service Bulletin is approved under the authority of Letter of DOA Acceptance ref. FOCA.21J.002. Pilatus advises Operators/Owners to check with their designated 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. H. Manpower I. Weight and Balance (1) Weight Change None. (2) Moment Change None. Man-Hours Borescope Inspection Corrosion Preventative Application Preparation 0.50 - Do the corrosion inspection with the borescope 0.50 - If necessary, apply the corrosion preventative - 0.50 Close-Up 0.50 - TOTAL MAN-HOURS 1.50 0.50 SERVICE BULLETIN Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 3 of 12 J. Electrical Load Data Not changed. K. Software Not changed. L. References Aircraft Maintenance Manual (AMM): 12-00-00, 20-31-00, 20-40-01. Tool and Equipment Manual (TEM): 20-40-01, 20-40-02. M. Publications Affected AMM: 05-10-20. N. Interchangeability of Parts Not applicable. Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 4 of 12 SERVICE BULLETIN 2. Material Information No modification kit is required for this Service Bulletin. Operators who require further information on Price and Availability should contact their Customer Liaison Manager at: Pilatus Aircraft Ltd, 6371 Stans, Switzerland. Operators are requested to advise Pilatus Aircraft Ltd. 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 None. (2) Operator Supplied Materials (Ref. AMM, 20-31-00): C. Material Necessary for Each Spare None. D. Re-identified Parts None. E. Tooling - Cost and Availability MATERIAL NO. DESCRIPTION QTY REMARKS P01-010 SOLVENT A/R Or equivalent P02-031 ABSORBENT PAPER A/R Or equivalent P10-015 CPC ARDROX AV 30 A/R Only required when corrosion not found to brackets with cadmium plated anchor nuts PART No. DESCRIPTION QTY REMARKS 904.21.06.622 CORROSION TREATMENT EQUIPMENT, PUMP 1 TEM 20-40-01 904.21.06.623 CORROSION TREATMENT EQUIPMENT, PRESSURE CUP 1 TEM 20-40-02 - BORESCOPE (MINIMUM X 10) 1 Local supply SERVICE BULLETIN Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 5 of 12 - ANGLE TUBE 1 Local supply to dimensions given in Fig. 1, Sheet 2 PART No. DESCRIPTION QTY REMARKS Service Bulletin No: 57-017 Date: Sep 06/19 Rev. No. Date: Page 6 of 12 SERVICE BULLETIN 3. Accomplishment Instructions WARNING: BE CAREFUL WHEN YOU USE THE CONSUMABLE MATERIALS. OBEY THE MANUFACTURERS HEALTH AND SAFETY INSTRUCTIONS BEFORE. A. Preparation (1) Put a warning sign “DO NOT OPERATE THE FLIGHT CONTROLS” in the front and rear cockpits. (2) Remove the LH (L 1) and RH (R 1) wing tip fairings (Ref. AMM, 12-00-00). (a) Remove and keep the 18 screws that attach the wing tip fairing to the wing. (b) Disconnect the position light electrical connector. (c) Disconnect the bonding lead from the wing. (d) Remove the wing tip fairing. B. Inspection (1) Do a borescope inspection to find corrosion and to identify the type of anchor nuts on the brackets on the LH and RH middle ribs 23 (Ref. Fig. 1).