Prop installation a potential 'killer' !

[Vern]

In the last few months three friends have had 'bad prop days.' Let's all keep an eye on these potential killers!

1) One friend had just about completed his cowling and spinner install when it was noted that something was just 'not quite right' about the install. After scratching heads for awhile, measuring engine mounts,checking donuts,etc., it was discovered that one of the blades on the big Hartzell was 1.5 inches ahead of the other when in the horizontal position. What could possibly be wrong? Turned out the prop bolts had not yet been torqued even though they felt tight. All the cowl trimming and fitting had to be redone after glassing in the erroneously trimmed areas.

2) Another friend landed from a x-country with his teenage daughter and felt something was not right with his engine. Cruise felt OK,but idle was very rough. While removing the cowl, he happened to pull on his Hartzell blade only to have it move! Turns out that after about 200 hours of flying and angels working overtime protecting him, that in the original prop install the starter ring/prop index collets had been missed.In fact, he did not know there was an index point. The prop bolts had been snugged down and they held until the starter ring wore thru to the index collet size and the prop began to wiggle. He had apparently never checked his prop tracking during the original installation. Truly a close one!

3) Another friend had his prop loosen inflight and break some bolts enough to cause bad vibration. He barely got on the ground.

[osxuser]

I agree, people don't pay enough attention to propellers. Personally I'd stick with metal or wood, no composites until the technology improves on them. Remember the TBO on your CS prop and send it to a repudable shop. A Fix metal prop should be ground and inspected every 10 years or so depending on usage. And always have someone double check your work after installing your prop.

[rv8ch]

Originally Posted by osxuser

Personally I'd stick with metal or wood, no composites until the technology improves on them.

What kinds of problems do you feel composite props have? I was under the impression that they were pretty well-tested.

[Highflight]

Originally Posted by osxuser

I agree, people don't pay enough attention to propellers. Personally I'd stick with metal or wood, no composites until the technology improves on them. Remember the TBO on your CS prop and send it to a repudable shop. A Fix metal prop should be ground and inspected every 10 years or so depending on usage. And always have someone double check your work after installing your prop.

I'm curious to know what, of the three examples of failure given above, prompted you to single out composite props? The subsequent reasons for the 3 different problems had nothing to do with composite props; only builder error (and 2 of the 3 were identified as Hartzell props... the other failure was from loose bolts, not a prop failure).
I'd also be interested to know where you found a statistical failure comparison rate of composite props vs. "production" wood or metal props.