I agree there is no way that you can accurately simulate the behaviour of an
airplane without the use of derivatives. All the "real" simulators work this
way. Even a model based on simple linear derivatives will have many
limitations associated with it.


"Dave Hyde" wrote in message
...
Jay wrote...

the forces beyond that will be calculated for you...
**********

Change "calculated" to "estimated" and you'll be
close to correct. If you're doing a non-derivative
design and want some hope at all of being close
in your estimate you better understand the limitations
and assumptions that went into XPlane specifically
and blade element theory in general.

Dave 'carpe datum' Hyde