On Wednesday, December 18, 2013 8:33:51 PM UTC-7, Morgans wrote:
"Dave Nadler" wrote in message

...

A prospect was checking out the nifty Antares 18T

sustainer system somewhere over the forest west of ZWB,

when to his great surprise, the propeller departed.

Hell of a way to impress a prospect.



The problem is with the Solo propeller shaft with the

belt reduction system as used on, IIRC:

- Ventus CM (not V2)

- Duo T

- DG-100T

I'll bet any money the problem will turn out to be torsional harmonics.



Remember the problem with the BD-5? Some excellent research was developed

out of the problems of using a 2 cycle engine in that aircraft.



Seems I remember that one fix involved a sprag clutch (one was slipping) to

get over the torque reversal at some rpms.

--

Jim in NC


Russia AC-5m's have had some prop departures due to broken shafts. I believe one resulted in a fatal at North Las Vegas about two years ago. Inspections have uncovered cracks in others. IIRC, there was a fix worked.

Frank Whiteley