Hey you aerodynamics enginners:

Building an A-10 with twin .25FX engines that sit about 3 inches high off the trailing edge of the wing. If I were to make the engine platforms longer or were to raise them so that they have, oh about 4 to 6 inches clearance will I significantly change the thrustline or CG?

This is because you can't find props that are pitched enough but short enough to fly the plane.

Any help is appreciated.

Sina

Try a 3 blade prop. Moving the engines too much will seriously affect CG and thrustline.

Dr.1

The thrustline change -will- have a large effect in the nose-down direction, but there shouldn't any problem with the c.g.

sorry but can you elaborate - what do you mean by "The thrustline change -will- have a large effect in the nose-down direction"?

thanks a bunch...

Sina

You'll be moving the motor up. This increases their leverage around the c.g. with the longer moment arm.