Hey Andy,

Actually, it depends on the location of the engine in relationship to the CG. If you are behind the cg and push down the nose will rise, if infront of the cg and you push down the nose will drop...Make sense? Now, think about this....Your roo is hanging from a string at the cg, you push forward at the trailing edge of the fuse and the plane moves forward without any change in pitch. If you were to push forward at the turbine the plane would move forward but will also want to drop the nose due to the leverage arm created by the engine being higher. To couteract that moment, we shim the engine with a tad of down thrust to push the nose up slightly. This is a real laymans way of explaining it but you should get the idea.

Todd