Va and turbulent air penetration speed.

"Tony Cox" wrote in message ink.net...
"Dan Thomas" wrote in message
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"Tony Cox" wrote in message
link.net...
"Dan Thomas" wrote in message
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The only times I have heard of engine mounts failing on light
airplanes is when a prop throws part of a blade, or maybe the whole
blade on a constant-speed prop. The imbalance is more than enough to
rip the engine off the airplane. Blades will fail when propeller nicks
are left untreated and cracks develop. The prop is the most highly
stressed bit of metal on the whole airplane, and THAT'S what pilots
should be concerned about, not engine mounts.


Nah. Properly designed engine mounts would never let that happen.

Cessna 185 operated by JAARS Inc, South America, about ten years ago.
Threw a blade and the engine tore off the mount before the pilot could
shut it down. It turned sideways in the cowl, and the cowl was the
only thing keeping it from departing entirely. The O-520 mount is a
bed mount; if it had been the usual rear mounting the engine would
have fallen off.


What's a bed mount, Dan? I've always thought (hoped) that my
182 cowling would contain the engine. And there is always the
fuel line, throttle cable, and battery cable as a last line of defense


I couldn't trust a few wires and cables to keep the weight of the
engine attached to the firewall.
I spoke with a former 747 pilot who was into Formula 1 racing. He
had a single-seat (Cassutt?) racer that used an O-200 turning a tiny
prop at 4400 RPM to get the flat-out speed he wanted. I asked him
about the prop failure/engine departure scenario, and he told me that
he (and his buddies, in their airplanes) had a stout cable wrapped
around the engine and bolted to the firewall to cover this
eventuality. Apparently it had happened more than once before to other
unfortunate racers.

Dan