Magni M24 - N648CM - South Dakota - prop

One must never assume that a solid object impacting one prop blade at cruise PRPM must necessarily indicate on any other blades. Just tain't so. The wrench that went through my Warp Drive prop described above only indicated on the one blade it nicked.

Next, I just took a USC aero eng. student flying very recently, he turned his head to look behind us, catching the air behind his face shield at 70mph, ripping it off of the helmet and sending it through my brand new NR foam core prop. It too also nicked only one of the three blades.

Again, I had a 2-cycle exhaust spring go through a prop back when I was still flying smokers, nicking only one of the three blades.

Three for three, for me.

So you are telling me that an object big enough that hit the one blade so hard to actually have completely torn it off is going to only hit one prop blade at cruise RPM. I can see a spring do a light face shield flying off do that possibly but they won’t chop off a composite blade completely off of a DUC prop.
 
So you are telling me that an object big enough that hit the one blade so hard to actually have completely torn it off is going to only hit one prop blade at cruise RPM. I can see a spring do a light face shield flying off do that possibly but they won’t chop off a composite blade completely off of a DUC prop.
You seem to be assuming that if something hit the blade that it must have resulted in immediate separation. I see no evidence to support such an assumption. It's more practical to consider that an impact on a single blade would cause damage sufficient enough only to lead to separation somewhat later on.

Another thought: If the gyro is locked in position at a standstill and a 10" wrench is flung through the prop spinning at 1600 PRPM, the chances are greater it will impact additional blades than if the prop is screwing through the air, gyro in fwd motion as in my own case.

The pilot describes removing the cowling panels. Sounds like an excellent opportunity for a hand tool to be left on the engine, especially since nothing was found missing from the aircraft upon landing. Absent that, my next guess is a bird strike.

Would a DUC prop stand up to either event? Don't know, not a DUC expert, but I do know that a long, heavy hand tool can go through a prop and hit only one blade with the PRPM approaching TO speed, for whatever that's worth.

Seeing that this gyro had a rollover or rotor strike is disconcerting, to say the least. But everyone knows if a Warp prop looks OK it will absolutely stay together in flight. I know that this is not the case with foam-core props, many have self-destructed w/o prior impact. As for DUC, again, I cannot speak to them. But it seems really odd that any solid, composite prop blade would ever just sponataneously come apart w/o some external factor at play, regardless who fabricated it.

Stream of consciousness hits again, time to get off the keyboard and get my sorry ass into the shop and do some real work, customers are waiting for product and I'm backed up with current orders for months.

Hasta la vista, baby.
 
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I'm still wondering if a thorough preflight might have caught something.
 
You seem to be assuming that if something hit the blade that it must have resulted in immediate separation. I see no evidence to support such an assumption. It's more practical to consider that an impact on a single blade would cause damage sufficient enough only to lead to separation somewhat later on.

Another thought: If the gyro is locked in position at a standstill and a 10" wrench is flung through the prop spinning at 1600 PRPM, the chances are greater it will impact additional blades than if the prop is screwing through the air, gyro in fwd motion as in my own case.

The pilot describes removing the cowling panels. Sounds like an excellent opportunity for a hand tool to be left on the engine, especially since nothing was found missing from the aircraft upon landing. Absent that, my next guess is a bird strike.

Would a DUC prop stand up to either event? Don't know, not a DUC expert, but I do know that a long, heavy hand tool can go through a prop and hit only one blade with the PRPM approaching TO speed, for whatever that's worth.

Seeing that this gyro had a rollover or rotor strike is disconcerting, to say the least. But everyone knows if a Warp prop looks OK it will absolutely stay together in flight. I know that this is not the case with foam-core props, many have self-destructed w/o prior impact. As for DUC, again, I cannot speak to them. But it seems really odd that any solid, composite prop blade would ever just sponataneously come apart w/o some external factor at play, regardless who fabricated it.

Stream of consciousness hits again, time to get off the keyboard and get my sorry ass into the shop and do some real work, customers are waiting for product and I'm backed up with current orders for months.

Hasta la vista, baby.

Propellers are not designed to handle throwing 10 inch piece of metal tool through them. That is not right to ask a propeller to do.
If there was previous damage to the blade, your assumption is that the pilot simply did not catch it in pre-flight. Well anything is possible but the area where this happened is clearly visible and I do not think the pilot would have easily missed looking at that area.
Warp Drive is a strong prop but its MOI is over 912ULS limits and that creates problems like Sprag Clutches going out prematurely etc. Also, in a hard hit in Warp Drive one has to really check the gears and crank because it passes the shock loads right through. A blade that gives up does not. Something has to give. You decide if you want it to be your blade or your crankshaft. In the right application Warp Drive makes a lot of sense.

Hope you get your orders out soon. I had a customer fly off his AR-1C (enclosed) 915 from Zephyrhills to Texas today, got a gyroplane and an airplane inspected by a DAR yesterday and conducted a first test flight in that airplane today.
 
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