Welcome back Troyp: Yes most (not all) planes benefit from some down thrust, usually not more then 2 to 4 degrees. And some require right thrust to compensate for torque, again usually not More then 2 to 4 degrees. the best way to tell is by flying the plane in different attitudes, and observing how the plane flies. There is some real good info. at rcfaq.com on trimming airplanes, that helped me tremendously, a very informative sight, good reading, all of it. But unless the thrust angle is terribly off I would not think it would cause a crash. Always glad to help if I can.