ORIGINAL: Jeff_edge540

When I setup CG I must first prove that the wing incidences and engine thrust angle are correct. Without these being set you cannot test for good CG.

To test for wing incidences; climb to a very high altitude and push the plane over to a vertical nose dive and cut the throttle to idle. If the plane pitches to the top or bottom you must trim it out. Try to trim with elevator until you get a perfect down run without pitch.

Now, fly straight up at full throttle. Does the plane pitch to the top or bottom? If so, your engine thrust angle is not set right. Add down/up thrust until you can get a perfect up run without pitch (do not touch your elevator trims).

Now, fly straight and level. Does the plane pitch up or down? If so, it is probably a CG problem. Try moving the weight forward or aft to cure the pitching problem without touching the elevator trim. Once you can get straight and level without elevator trim AND get a straight down run (with the engine cut) AND get a perfect up run, you are pretty close to a perfect CG.

Now, roll inverted and fly straight and level.. Does it require a bunch of elevator correction? If so, you have a wing incidence problem. Adjust wing incidence and start the process all over again.

Ultimately, you should be able to fly staight up at full throttle without pitch problems, fly straight down with the throttle cut without pitch problems, fly straight and level without pitch problems, fly inverted at a 45 degree up angle without pitch problems and fly inverted straight and level with only a slight down pitch.