Promark P-70 post crash flight issues.

[Scott99205]

So I was shooting some video over a local river one afternoon. I had my son spotting from an adjacent bridge while I flew FPV. The flight was fine aside from some relatively heavy gusts, but this was my first time flying this stretch, so I was more interested in just scouting rather than footage quality. I took off from a flat area along side the river rather than on the bridge because the pedestrian area of the bridge is fairly narrow, and I didn't want to chance dropping my drone in the river ( the traffic area of the bridge is plenty wide, but with unpredictable traffic ). From where I was standing, I had to pop over top of a big maple tree on the river bank ( No problem ). The flight was bumpy and relatively unimpressive, but fighting the wind took it's toll on my battery and it executed a Return to Home ....which would have been all good.....if I had thought to set my RTH altitude a little higher.....it hit the canopy of the maple tree at full throttle, with enough velocity to carry it through the other side, where it tumbled and fell about 50 feet. The damage was pretty impressive. It knocked the camera loolo from the mount ( thankfully one of the cable stayed plugged in ) I flat out lost a blade guard, and broke a previously damaged one, put a couple interesting looking curves in two of my rotors, and cracked the housing on one of the arms. The cracked arm *feels* solid, like it's just a skin, not structural . I replaced the damaged/lost blade guards, and all four rotors . Took it out, recalibrated the GPS and Compass, and tried a test flight. It will take off, and hover at about 5 feet, looking slightly drunk, then it will slowly loose altitude till it reaches about 6" off the ground and will start air bouncing . If I throttle it up, it will go up to about 30' and stop. If I give it just a slight counter clock-wise rotation, while trying to go up, it will slowly corkscrew it's way higher, coming back down when I stop . Flying forward, from any altitude, will cause it to slowly loose altitude. This behavior is the same regardless of whether I use the controller, or my phone to fly it, so I don't think it's a controller issue ( besides, I didn't throw my controller into the trees at 20+ mph....lol ) .The motor shafts all look straight and undamaged. I suspect I'm going to be opening it up. Anyone else experience similar issues after a hard crash ? Any tips on what to look for ? ( Besides big trees ? )

Thanks in advance !!

Scott in Spokane