Any air being sucked in
from the front, and I don't believe there is, is not strong enough to
pick up rocks.

This brings up an interesting (to me, anyway) observation I made last
weekend, while parking over 130 aircraft.

Despite the fact that a propellor is putting out enough "wind" to pull
a 3000 pound aircraft across a grass field, I can stand literally
nose-to-nose with the spinner, and NOT get "sucked in" to the prop.

Thank goodness, I might add.

I knew this all along, after being parked a few hundred (thousand?)
times without dicing up the lineman, but I'd never personally observed
it before.

This seems counter-intuitive, though, and a casual observer would think
that the "suction" should equal the "out-flow". (Of course, it *does*
-- the air just isn't all coming in from directly in front of the prop
arc.)

At my airport our taxiway is in sad shape, and it's due to be repaved
this summer. We pick up new prop chips on most flights, despite NEVER
taxiing above 1000 RPM, and being extremely careful about where we
taxi. This seems to show that props DO suck rocks into them,
somehow...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"