Sheared Propeller Bolts

Re: Sheared Propeller Bolts

by Roger Lee » 11 years ago

Roger Lee

131 5.38k 5.44k

Interesting. I would think shear lugs would be better over just a bolt.

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Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: Sheared Propeller Bolts

by Dan Marotta » 11 years ago

Dan Marotta

2 11 4

UPDATE

Yesterday I installed to prop using factory bolts in anticipation of performing a dynamic balance. When I attempted to rotate the prop for better access to the lower bolts, I was unable to turn the engine. It's locked up solidly.

I went to the shop of the local Pipistrel distributor and he had one in the shop and we carefully moved the prop to feel the gearbox backlash. The engine was easy to turn a small distance before feeling compression building. Mine has no backlash that I can feel.

Following a prop strike a couple of months ago (a whole different story) I removed the gearbox and sent it to Florida for inspection/overhaul. I also measured crank runout and twist per the heavy maintenance manual. Both were well within spec. When the gearbox was returned, I installed it and flew perhaps 10 hours over several flights before this latest problem.

I will be removing the gearbox today to have a look and will report what I find.

Re: Sheared Propeller Bolts

by Dan Marotta » 11 years ago

Dan Marotta

2 11 4

Yesterday I loosened the starter and pulled it back as far as the firewall would allow. Could not turn the engine. Today I removed the propeller gearbox and... Could not turn the engine. Tomorrow I'll take the front cover off the oil pump to see if there's anything there and, with no luck there, will investigate the back of the engine to see if something got into the generator, starter, or water pump.

I'm open to suggestions...

Re: Sheared Propeller Bolts

by Dan Marotta » 11 years ago

Dan Marotta

2 11 4

Inspected the oil pump and back of the engine. Nothing out of the ordinary. Gonna start looking for a borescope.