The maiden flight of my V-Tail plane was quite scaring .
After take off in FBWA the plane begun to porpoise with 40 - 45° pitch angle , I was very surprised because with all the other planes with standard Pids the plane was always perfectly level , so I panic a bit leaving the throttle high for 20 seconds while I was trying to turn .
Only decreasing the throttle to minimum the plane reduces heavily the porpoising and start to better respond to radio commands .
Then I only thought to bring it back and land, it flew well with no throttle .
Here is the log , I edited it to reduce the size Dataflash Log
I’m not an expert but looking at the log I saw some weird things, looking for some help to understand the reasons for this odd behavior.
1- The V-Tail outputs , CH_Out 2 & 4 (ailerons is CH_Out 1) , had a very small range
2- The PID PI , was negative , went to -10, does that means that the plane was Tail heavy ?
3- Mixing value was 0,7 , is that too much low for a V-Tail and that the explanation for small V-Tail output ?
4- The purpoising was much more with high throttle, is it because of low PID P , for Pitch and roll ?
If the plane was tail heavy it would explain why with full motor it goes nose up.
Do not understand what make it went nose down since the throttle was still high and the plane kept a lot of speed far from stall condition.
Thanks for your suggestions
