Hi JG, you really don,t need anything fancy and you have already found your answer and proven it. As Chucksolo69 pointed out that handlaunching a light high thrustline glider like airplane at full power will always pitch over untill trim speed is reached and the very simple solution is to simply only use partial power and after launch you can power up to whatever you would like.

I have a number of old timers which are the opposite problem and I hand launch them often, the solution is exactly the same. They will pitch to vertical if hand launched with full power. Hmm launch at partial power and then go vertical if I want. Same solution reduced power at launch.

I also have some seaplanes with a high mounted engine above the wing and although much heavier so do not hand launch. But these also will then to pitch downward every time untill trim speed is reached when throttle is suddenly applied. What these airplanes do as well as some light glider like foamys is to angle the engine mounting to an upward angle (up thrust) an this will tend to minimise this although not completely.


John