identification of non-conforming propeller pitch drive axle a00.pdf · identification of...

Service Bulletin Document-No.: SB-100-007

Service Bulletin No.: SB-100-007 Issue: A.00

SLO.DOA.002 Identification of non-conforming

propeller pitch drive axle Page: 1 of 6

All rights reserved.

Identification of non-conforming propeller pitch drive axle Category: MANDATORY Subject: Identification of propeller pitch drive axles with non-conforming

thread and corrective action Affected Aircraft s.n.: All Sinus, Virus, Virus SW and ALPHA trainer aircraft equipped

with an 80 HP Rotax 912 engine that have a Pipistrel VARIO variable pitch propeller installed

Time of Compliance: Compliance to part 1 required at the next scheduled inspection

according to applicable AMM or no later than 25 hours of operation after the issue date of this SB, whichever comes first. Compliance to part 2 required immediately, but subject to the outcome of part 1

Reason: To prevent the occurrence of in-flight propeller pitch control

system failure, which could cause sudden and potentially dangerous propeller pitch changes.

Actions: 1) Identify non-conforming propeller pitch drive axle 2) Perform applicable corrective action Documents: [1] Latest revision of applicable IPC [2] VARIO propeller operator’s manual REV3 Required Material: N/A Mass and Balance: Neglible Required Records: Compliance with this Service Bulletin must be recorded in the

aircraft’s documentation and confirmed by submitting the provided and completed Service Bulletin Compliance Sheet (Attachment) to Pipistrel.





Prepared: Verified: Approved: Replaces issue:

A. B. Horvat T. Tomazic

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Revision history:

Issue Alteration Affected Pages Date

A.00 Initial Issue All 24.08.2017

Verified and approved under the authority of DOA-No.: SLO.DOA.002 Date: 24.08.2017

Head of Airworthiness Design Organisation SLO.DOA.002







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Reason: Some pitch drive axles (P/N 1153056, see [1]), which are installed in all Pipistrel’s VARIO variable pitch propellers, have been found to be non-conforming, because they were manufactured with incorrect thread. Although they don’t pose an immediate safety threat, eventual thread wear could cause sudden and potentially dangerous pitch changes towards higher RPM during aircraft operation. They need to be identified and corrective action is required. Accomplishment instructions: Part 1: Identify non-conforming pitch drive axle The thread in question can be found at the end of the pitch drive axle and is supposed to be M10 x 1.0. Perform the following to determine whether the thread on your pitch drive axle is conforming or non-conforming:

a) Remove screws securing spinner to spinner backplate b) Feather the propeller c) Remove spinner d) Locate pitch drive axle thread protruding out of propeller hub, rest Vernier

caliper jaws up against nut and measure major diameter as seen in Figure 1. Thread major diameter ≤ 9.65 mm = non-conforming

Figure 1: Axle thread major diameter measurement







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NOTE: The contents of this SB apply to ALL VARIO propeller pitch drive axles, regardless of whether they’re installed on aircraft or not. All pitch drive axles that have been removed from aircraft or are being kept in stock as spare parts must be inspected as per part 1 of this SB. NOTE: When reinstalling the spinner make sure to align the notch in its edge with the notch in the edge of the spinner backplate (see Figure 2).

Figure 2: Spinner and spinner backplate alignment

Part 2: Perform applicable corrective action Destroy and dispose of all non-conforming pitch drive axles that aren’t installed in aircraft. A photo of the destroyed axle has to be sent to Leon Brecelj ([email protected]) along with any relevant information (i.e. aircraft serial number, invoice number). Do not remove any/all non-conforming pitch drive axles that are installed in aircraft. In this case the complete Pipistrel VARIO variable pitch propeller must be removed from the aircraft and overhauled by PIPISTREL AUTHORIZED SERVICE PERSONNEL. Contact your Pipistrel distributer to have this arranged/performed. Perform the following to remove the Pipistrel VARIO variable pitch propeller (see [1]):

a) Loosen/remove M6 bolt (P/N 1153062, circled in Figure 3) securing pitch regulation lever (P/N 1153004) to propeller axis (P/N 1153064)

b) Loosen/remove four M8 bolts (P/N 1153063) securing the propeller to the engine (highlighted in Figure 1)

c) Remove propeller







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Figure 3: Bolt securing pitch regulation lever to propeller axis

Once propeller overhaul is complete, perform the following to reinstall the Pipistrel VARIO variable pitch propeller (see [1]):

a) Fasten propeller to engine according to [1] and torque according to [2]. Replace locknuts with new ones and mark with paint marker.

b) Fasten regulation lever (P/N 1153004) to propeller axis (P/N 1153064) using M6 bolt (P/N 1153062, circled in Figure 3)

c) Fasten spinner to spinner backplate. Align notches. Testing on the ground should be performed to make sure propeller pitch control system functions properly and normal pre-flight RPMs are observed. Notify your local Pipistrel dealer of all and any issues.

Personnel and site requirements: Personnel: No special requirements. Part 1 of this SB can be accomplished by owner. Propeller removal/installation should be carried out by appropriately qualified personnel. Other publications: N/A Manhour estimation: 30 minutes Additional Questions? All questions relating to this SB can be forwarded to Pipistrel Maintenence department via telephone: +386 5 364 38 83 or email: [email protected]

END OF SERVICE BULLETIN.







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Service Bulletin Compliance Sheet

Please complete this page and send it to Pipistrel The Service Bulletin mentioned above was incorporated: Date: Aircraft S/N: Registration: Owner: Comments (Difficulties encountered, deviations, recommendations, etc.):