I'm going to make some offhand assumptions:

1. This is Wisconsin dirt covered with either green or brown grass quite
evenly.

2. The plywood will be 90% in contact with a supporting surface of
grass/ground

3. The airplane will weigh something on the order of 3000 pounds spread
evenly over all three wheels.

If this is true, then the plywood will have a supporting role 10% of 1000
pounds, or 100 pounds over a square foot, or a little less than 1 psi. My
best guess is that 3/8 would do, but beltandsuspenders would be half-inch.
That's what I'm bringing along.

Jim



"john smith" wrote in message
...
Okay, I admit I don't know how much weight a one-square-foot piece of 3/8,
1/2, or 3/4 inch plywood will bear before breaking. I err on the
conservative side. :-))
What would be the appropriate size for 210 or Cherokee Six six aircraft?

RST Engineering wrote:
1" ply? Jeez, are you flying a DC-3 in?
Jim

"john smith" wrote in message
For your airplane:
three pieces of 1" thick plywood (one for each wheel)