178 – Propeller Mystery Solved!

Airplane Owner Maintenance - By Dean Showalter

We’ll talk about these photos in this week’s podcast episode, and how they explain the problem Aram was having with his propeller. (Photos courtesy of Dave Pasquale of Pasquale Aviation LLC.) Dave is removing the prop to be sent out for repair, and will reinstall it when the repair is finished.

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But first, I want to introduce a podcast listener in Germany.

Dmitry is the owner of a 1965 Bolkow 208C Junior. He sent me an email last week along with some photos. He’s the kind of airplane owner we love around here at Airplane Owner Maintenance! He’s very involved in the maintenance of his airplane. Thanks Dmitri, for sharing a bit of your story with us!

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Now back to Aram’s Beech 278 prop on his P35 Bonanza… here’s the bottom line answer to the mystery:

Due to a leaking o-ring seal around the piston inside the prop hub, oil was pushed into the forward end of the prop hub which caused a hydraulic lock and prevented the prop blades from rotating. This condition would not allow the governing system to function.

Dave Pasquale got a great video of turning the prop blades after removing the snap ring, which pushed the plug forward and let the unwanted oil out of the air cavity in the prop hub.

The bright side of all this is that Aram’s engine does not need to be disassembled, (which would have been the case if there was a problem with the engine transfer collar near the prop governor.)

The propeller will go to H&H Propeller Service in Burlington, North Carolina for an IRAN (Inspect and Repair As Necessary,) and then be reinstalled on the airplane.

Thanks to all of you who contacted me about this issue with email and voice messages. I appreciate all the ideas and feedback!

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Also mentioned in the podcast this week:

Episode 164 – Airplanes, Motorcycles, and Bob’s Grass Runway.

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