I calibrate aircraft performance for X-Plane simulator aircraft.
The way I understand it, the purpose of takeoff trim is basicly to have the correct trim on initial climb (V2+15 or whatever). So, that if you handfly
the acf it will climb out straight as a missile at the
calculated pitch without additional elevator input. To much up trim will cause a
"rollercoaster" climb and in worst case a stall.
But hey, this is simulator theory
Cheers,
M