Probably 400 ft....I have both the engine with UP Thrust and the PIPE with max up thrust..... With a level stab you climb out on about a 45 degree angle....Once in the air...trimming down to prevent the climbing and assume level flight.... is not an issue... HOWEVER , if you have to climb back out ( miss approach for example) you MUST hold elevator up until full speed is regained and altitude,,,ANY release of back pressure will result in a violent pitch over ( like a waterfall) ....I'm hoping that reducing the UP thrust shimming of pipe and engine..will reduce the need for down trim in level flight and thus will reduce the violent pitching with power.....Adding a throttle to elevator mix and the gyro on elevator should calm things down a lot as well