OPTIONAL SERVICE BULLETIN OSB

DAI OSB 42-131 Page 1 of 4 OPTIONAL SERVICE BULLETIN OSB 42-131 I TECHNICAL DETAILS I.1 Category Optional. I.2 Airplanes affected Type: DA 42, DA 42 M Serial numbers: 42.004 through 42.427 42.AC001 through 42.AC151 42.M001 through 42.M027 Only airplanes with a TAE 125-02-99 or TAE 125-02-114 engine with exhaust pipe DAI P/N D60-9078-06-01_01 / Technify P/N 52-7810-H0014 01 installed are affected. I.3 Date of effectivity I.4 Time of Compliance At owners discretion. Note: Exhaust pipes with DAI P/N D60-9078-06-01_01 / Technify P/N 52-7810-H0014 01 are no longer supplied. Compliance with this OSB may become necessary upon required replacement of such an exhaust pipe installed. I.5 Subject Re-installation of exhaust pipes with directly attached heat shield as a replacement for exhaust pipes without directly attached heat shield. Re-qualification of this exhaust pipes with directly attached heat shield previously removed. Repair of heat shield and heat shield attachment to base pipe. ATA-Code: 78-00 I.6 Reason Exhaust pipes with DAI P/N D60-9078-06-01_01 / Technify P/N 52-7810-H0014 01 provided not the desired durability and will be no longer supplied. This service bulletin describes the work necessary to re-install original design exhaust pipes attached heat shield (DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810-H0001 02, 52-7810- H0001 03 or 52-7810-H0001 04) as a replacement including the installation of an additional exhaust bracket. In addition this service bulletin provides test methods to re-qualify original design exhaust pipes attached heat shield (DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810-H0001 02, 52-

DAI OSB 42-131 Page 2 of 4 7810-H0001 03 or 52-7810-H0001 04), that have been removed because of having more than 1500 flight hours time since new (TSN) or unknown TSN. In addition this service bulletin provides repair methods for original design exhaust pipes attached heat shield Technify P/Ns 52-7810-H0001 03 and 52-7810-H0001 04, that have a failed heat shield attachment. Note: Compliance with this OSB on one engine only is considered acceptable. I.7 Concurrent Documents None. I.8 Approval The technical information or instructions contained in this document relate to the Design Change Advisory No. MÄM 42-943/a, which has been approved under the authority of EASA Design Organization Approval ref. EASA.21J.052. The technical content of this document has been approved under the authority of DOA ref. EASA.21J.052. I.9 Accomplishments / Instructions Comply with WI-MSB 42-131, latest effective issue. I.10 Mass (Weight) and CG The change in mass and CG is negligible. II II.1 PLANNING INFORMATION Material and Availability See WI-MSB 42-131, latest effective issue. Materials including drawings are available from Diamond Aircraft Industries. II.2 Special Tools None. II.3 Labour Effort Re-Installation of Exhaust Pipe: approx. 1 hour II.4 Credit None. II.5 Reference Documents DA 42 Series Airplane Maintenance Manual, Doc. No. 7.02.01, latest effective issue.

DAI OSB 42-131 Page 3 of 4 III REMARKS 1. All work must be done by a certified aircraft service station or a certified aircraft maintenance mechanic. 2. All work, particular that which is not especially described in this Service Bulletin, must be done in accordance with the referenced Maintenance Manual. 3. Completion of all work must be recorded in the log book. 4. In case of doubt contact Diamond Aircraft Industries GmbH.

DAI OSB 42-131 Page 4 of 4 EXECUTION REPORT TO SERVICE BULLETIN OSB 42-131 AIRPLANE INFORMATION Airplane Serial Number Airplane Registration Airplane Operator Hours of operation of airplane No. of landings Hours of operation-engine Typical operation of airplane private, club, training, other Exhaust installation carried out on O LH Engine O RH Engine O both Engines Date, Name, Sign Please fax the completed form to Fax No. +43-2622-26700-1369 or e-mail to executionreports@diamond-air.at

Page 1 of 18 WORK INSTRUCTION I GENERAL INFORMATION I.1 Subject Re-installation of exhaust pipes with directly attached heat shield as a replacement for exhaust pipes without directly attached heat shield. Re-qualification of this exhaust pipes with directly attached heat shield previously removed. Repair of heat shield and heat shield attachment to base pipe. I.2 Reference Documents DA 42 Series Airplane Maintenance Manual, Doc. No. 7.02.01, latest effective issue. Design Change Notice: OÄM 42-315 Alternative Exhaust Clamp Sheet I.3 Remarks a) All work must be done by a certified aircraft service station or a certified aircraft maintenance mechanic. b) All work, in particular if not described in this work instruction, must be done in accordance with the referenced maintenance manual. c) For conversion factors between SI units and US/Imperial units refer to AMM Chapter 02. d) In case of doubt, contact Diamond Aircraft Industries GmbH. II DRAWINGS, SPECIAL TOOLS & MATERIALS II.1 Drawings A01-VR00735-00-0201 II.2 Special Tools No required special tools.

Page 2 of 18 II.3 Material A. Material for Re-Installation of Exhaust Pipe with Directly Attached Heat Shield Note: Material is for installation on one engine only. Quantity Part Number Description 1 DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810-H0001 02, 52-7810-H0001 03 or 52-7810-H0001 04 Exhaust Pipe 1 D60-7806-00-01 Exhaust Clamp 1 (pos. 4) 1 D60-7806-00-02 Exhaust Clamp 2 (pos. 5) 1 D60-7806-00-03 Exhaust Sheet (pos. 6) 2 DIN 912-M5x20-A2 Hexagon Socket Head Screw (pos. 7) 2 LN 9338-M5 K-Nut M5 (pos. 9) 4 DIN 125-A5.3-A2 Washer A2 (pos. 11) 1 LN 9037-06016 Hexagon Screw (pos. 8) 1 LN 9338-M6 K-Nut M6 (pos. 10) 4 BN 806-12x6,2x0,6 Spring Washer (pos. 12) 1 DIN 9021-B10.5-ZP Washer (pos.13) Material is available from Diamond Aircraft Industries.

Page 3 of 18 B. Material for Re-Qualification of Exhaust Pipes Material for Air-Pressure Test: Quantity Part Number Description 1 VR00735-00-02 01*) Adaptor incl. pressure connection and o-ring 1 VR00735-00-01 01**) Pressure Pad 3 NM-0000-02355 01**) Hexagon Screws M8x40 3 NM-0000-01294 01**) Hexagon Nuts M8 6 NM-0000-00040 01**) Washers M8 Material including drawing is available from Technify Motors GmbH. *) Adaptor may also be produced locally by a maintenance shop in accordance with the attached drawing A01-VR00735-00-0201 and standard grade fittings and o-rings **) Standard DIN Hardware available may be used for the test. Material for Hot-Water Test ***): Quantity Part Number Description 1 D60-9078-06-01ST01 Cap 1 D60-9078-06-01ST02 Rubber 3 DIN 933-M8x30-A2 Bolt 3 DIN 934-M8-A2 Nut 3 DIN 125-M8 Washer Material is available from Diamond Aircraft Industries. ***) Cap an Rubber may also be produced locally by a maintenance shop. Standard DIN Hardware available may be used for the test. For the Cap use 3 mm thick stainless steel sheet metal. For the Rubber use 2 mm thick rubber mat of EPDM, FKM, Viton or equivalent. Dimensions:

Page 4 of 18 III INSTRUCTIONS III.1 Re-Installation of Exhaust Pipes with Directly Attached Heat Shield 1 Remove engine cowlings in accordance with (i.a.w.) AMM section 71-10. 2 Remove Exhaust Pipe DAI P/N D60-9078-06-01_01 / Technify P/N 52-7810-H0014 01, previously installed under OSB 42-122, i.a.w. AMM Section 78-00. Make sure that the intermediate flange of the engine is installed correctly to the forward engine shock mount. Align a ruler with the straight part of the bottom side of the intermediate flange as shown in the picture below. The distance between screw (pos. 3) and the ruler must be 13mm. 3 intermediate flange pos. 3 4 Install Exhaust Pipe with directly attached heat shield DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810-H0001 02, 52-7810-H0001 03 or 52-7810-H0001 04 i.a.w. AMM Section 78-00. 5 Remove the screw (pos. 3) from the front shock engine mount.

Page 5 of 18 Install the exhaust clamp i.a.w. the pictures without tightening the bolts. 5 4 12 10 8,12 6 13 3 6 7 11 9

Page 6 of 18 Make sure that exhaust clamp 1 (pos.4) and exhaust sheet (pos. 6) are arranged as shown in the following pictures: pos. 6 pos. 4 correct installation 7 Note: The correct order of arrangement is: hexagon screw (pos. 8) spring washer (pos. 12) exhaust sheet (pos. 6) 2 x spring washer (pos. 12 ) exhaust clamp (pos 4) spring washer (pos 12) K-nut M6 (pos 10) 8 Tighten Hexagon Screw (pos. 8) until the spring washer pre-tension is 1.5 mm between the metal sheets. 9 Tighten Hexagon Socket Head Screws (pos. 7) equally on both sides with 5 NM (3.7 lbf.ft.).

Page 7 of 18 10 Check if the Hexagon Screw (pos. 3) can be installed without applying side force to the exhaust pipe. If the Hexagom Screw (pos. 3) cannot be installed without applying side force to the exhaust pipe: - Loosen the exhaust assembly at the manifold an re-align the exhaust pipe with the lower cowling installed in order to keep the pipe centered in the lower cowling cut-out and with adequate clearance to surrounding components. Re-install the exhaust assembly i.a.w. AMM, section 78-00. - If necessary loosen Hexagon Socket Head Screws (pos. 7), re-align exhaust pipe clamp and tighten Hexagon Socket Head Screws (pos. 7) i.a.w. item 6. Check if the Hexagon Screw (pos. 3) can be installed without applying side force to the exhaust pipe. If the Hexagon Screw (pos. 3) cannot be installed without applying side force to the exhaust pipe: - Modify the exhaust pipe bracket by re-working the hole for Hexagon Screw (pos. 3) as shown in the picture below so that the Hexagon Screw (pos. 3) can be installed without applying a side force to the exhaust pipe. Do not remove more material than is needed for tension free installation. 11 smoothen the edges

Page 8 of 18 12 13 In case it is not possible to install the exhaust clamp without adequate clearance between exhaust pipe and cowling / surrounding components and without applying tension to the exhaust pipe, install an alternative exhaust sheet i.a.w. DAI OÄM 42-315. Note: The alternative exhaust sheet and corresponding installation instruction (OÄM 42-315) may be obtained through Diamond Aircraft Industries Austria (support@diamond-air.at). After verification that the Hexagon Screw (pos. 3) can be installed without applying tension to the exhaust pipe and that there is adequate clearance between exhaust pipe and lower cowling cut-out / surrounding components, secure Hexagon Screw (pos. 3) with Loctite 272 and torque i.a.w. Technify Motors Repair Manual RM-02-02, Section 71-20.01. Examine heat shielding in the engine compartment. Ensure: - Installation is compliant with installation requirements in WI-OSB-42-122, Revision 3 or later - No damage or wear to heat shielding Note: Heat Shield Installation Requirements: - Heat shield at the front shock mount: heat shield 14 - Heat protection patch to upper cowling:

Page 9 of 18 - Heat protection patch to the air inlet duct of the lower cowling 5 mm 5 mm - Small heat protection patch to lower cowling: 5 mm

Page 10 of 18 - All patches view: - Edge sealing of heat protection patches: heat protection patch Dow Corning 732 cowling composite material

Page 11 of 18 heat protection patch Dow Corning 732 cowling composite material - Heat protection shield to the coolant tube: Note: For detailed installation Procedures refer to in WI-OSB-42-122, Revision 3 or later. 15 Clean working areas, check for foreign objects. 16 Install engine cowlings i.a.w. AMM section 71-10. - Make sure sufficient clearance of the exhaust pipe is provided. 17 Do an engine test i.a.w. AMM section 71-00. 18 Do a post engine test inspection: - Remove engine cowlings in accordance with (i.a.w.) AMM section 71-10. - Examine exhaust pipe and cowlings. Ensure no signs of contact and verify sufficient positive clearance of exhaust pipe. In case of contact, re-align exhaust pipe routing. - Install engine cowlings i.a.w. AMM section 71-10. 19 Make all necessary entries in the airplane logs.

Page 12 of 18 III.2 Re-Qualification of Exhaust Pipes DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810-H0001 02, 52-7810-H0001 03 or 52-7810-H0001 04 Note: Either Procedure 1 or 2 may be used for re-qualification of an exhaust pipe. Note: Re-qualified exhaust pipes are considered having a TSN of 1500 FH. Procedure 1: Air-Pressure Test Examine Exhaust Pipe visually. - Clean exhaust pipe. - Ensure no visible cracks on inner pipe where visually accessible. - Ensure no visible cracks on heat shield. - Ensure heat shield is firmly attached to the inner pipe. 1 Note: On Exhaust pipes Technify P/Ns 52-7810-H0001 03 or 52-7810-H0001 04 the heat shield is welded to the exhaust pipe at the marked points. If a single welding point is cracked the heat shield is considered to be loose. This defects may be weld-repaired. Refer to Section III.3. Mount the adapter (VR00735-00-02 01 incl. pressure connection and o-ring) with the exhaust pipe, therefore use 3x M8x40 hexagon screws (NM-0000-02355 01), 3x M8 hexagon nuts (NM-0000-01294 01) and 6x washers (NM-0000-00040 01). 2

Page 13 of 18 Position the pressure pad (VR00735-00-01 01) in the internal exhaust pipe and connect the hand compressed air pump to the adapter and fill pressure pad with app. 1 bar. 3 Apply 0.5 to 0.7 bar to the exhaust system with a compressed air pump. 4 5 If no immediate pressure loss is detected the test is passed and the exhaust pipe is serviceable.

Page 14 of 18 Procedure 2: Hot Water Test CAUTION: When handling with hot water, use adequate safety equipment and precautions to protect yourself and co-workers from any harm when getting in contact with hot water or heated materials. Examine Exhaust Pipe visually. - Clean exhaust pipe. - Ensure no visible cracks on inner pipe where visually accessible. - Ensure no visible cracks on heat shield. - Ensure heat shield is firmly attached to the inner pipe. 1 Note: On Exhaust pipes Technify P/Ns 52-7810-H0001 03 or 52-7810-H0001 04 the heat shield is welded to the exhaust pipe at the marked points. If a single welding point is cracked the heat shield is considered to be loose. This defects may be weld-repaired. Refer to Section III.3. Install the cap with rubber on the exhaust flange and support installation in a vice i.a.w. picture below. 2 Cap, Rubber Washer, Nut, Bolt

Page 15 of 18 Use a funnel to fill the center pipe of the exhaust with exactly 1 liter of hot water (approx. 70 C). Be very careful to not spill any water. In case of spillage, remove water thoroughly and immediately. 3 center pipe

Page 16 of 18 Leave the water in the exhaust for a period of ten minutes. Then check for leakages. - Check for signs of water in the area of the manifold. 4 - Discard water and remove the cap and rubber. Use caution, the water may still be hot. - Let the exhaust dry. Compressed air may be used to accelerate drying. 5 If there are no visible leaks or water coming out underneath the heat shield were detected, the exhaust is serviceable.

Page 17 of 18 III.3 Repair of Heat Shields of DAI P/N D60-9078-06-01 / Technify P/Ns 52-7810- H0001 03 and 52-7810-H0001 04 Note: If the heat shield is loose a one time repair as follows is permitted. 1 Prepare exhaust pipe for welding: - Drill the cracked welding point of the heat shield with a diameter of approximately 6 mm. Do not thrill thru the inner exhaust pipe. Ref. picture below. If the welding point at the elbow is cracked do also drill this welding point and centre the heat shield as shown in the picture below.

Page 18 of 18 2 Welding: - Weld the heat shield at the drill holes to fix the heat shield to the exhaust pipe using MAG welding/gas metal arc welding (reference number 135 according to DIN EN ISO 4063). Use 1.4316/AISI 308L filler material. Note: The staff must be qualified according to ISO 24394, AWS D17.1, HB5299.1 or an equivalent national aircraft/aerospace welding approval accepted by the responsible authority. Note: No re-welding of the manifold joint is allowed.