Landing on snow-covered grass

That is my experience. Think about the relative velocity of air through
the prop at full RPM. Now think about the relative velocity of the air
through the prop when moving at the 5-10 MPH most recommend before using
full throttle. The difference is virtually nil. If you are going to
pick up gravel, you will pick it up at 10 MPH about as readily as at 0 MPH.

Gotcha.

Rather than peg it to a specific ground speed, I think the procedure
is more along the lines of this:

"Gradually increase throttle and RPM at a rate commensurate with the
increase in ground speed." Using this rule of thumb you might not
hit full throttle till you're 25% of the way down the runway.
(Everything depends on runway *length*, of course...)

Personally, on a loose surface I would not go to full throttle until
I'm rolling a LOT faster than 5 to 10 mph.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article ,
Matt Whiting wrote:


It isn't belief. It is experience.

Matt


Just not enough experience or perhaps not the right kind. G

I've seen C-130s pick up debris from the ground and the props on a C-130
are one heck of a lot farther from the ground than a Cessna prop.

The next time your sitting out there on the gravel doing a runup or
using the brakes/power short field technique have your window open.
Those little pops and clicks you're hearing are pieces of
dirt/sand/gravel/rock hitting the prop. Every single one of them is
pitting the leading edge of backside of the prop.

What I'm passing on to you I didn't make up, I learned this from people
around me, guys that make a living flying off-airport. Of my 3400 hours
about 2500 is in Alaska with the majority of that operating from other
than paved runways.

I had a great learning experience flying jumpers. We had two airplanes,
I flew the red one, Mr Roughstick flew the white one. The white one had
a ****ty looking prop and got cylinder changes each year. The red one
had a clean prop and never got a cylinder. Mr Roughstick taught me a
lot about how NOT to operate an airplane. He would use a big burst of
power to start rolling (hear that tink tink tink?), I would not use more
than 1200RPM (seems to be a magic number, don't know why) to start
rolling. There was a distinct, visible difference in the condition of
the props on the tow airplanes.