On Fri, 20 Apr 2012 08:43:49 +0000, Peter F
wrote:

At 03:36 18 April 2012, Bob Gibbons wrote:
-- Max gross with or without the engine is 500kg. The issue with the
engine in place is the 255kg non-lifting limit. With the engine in
place, the pilot weight determines whether the max gross of 500kg or
the non-lifting limit of 255kg kicks in first.

You've lost me somewhere.

Why does pilot weight stop you getting to max gross as long as the wing
tanks are big enough?

Assuming tanks *are* big enough to get to max gross without the engine then
it should be a piece of cake to get there *with* the engine.

PF

PF, I agree this was a confusing way to state the impact of the
non-lifting limitation.

What I was trying to convey is the impact of the pilot weight on the
amount of water ballast you can add before hitting the max gross
limit.

As I mentioned, at my weight, I can add 28 gal before reaching max
gross of 500kg. With the engine installed, I am right at the 255kg
non-lifting limit.

On the other hand, if I weighed 20 lbs less, I could add 31 gal of
water before reaching the 500kg limit.

If I took the engine out, I could add 40 gal of water before reaching
the 500kg limit.

Sorry for the confusion.

Bob