I'm new to drones; not new to RC flight. This is my first Phantom. Generally impressed, yet greatly concerned. Plan: Slow approach and fly-over shot of a town clock in a park. (one of those tall old-towne iron post-mounted clocks they put in parks) Very calm day, almost no wind which was what convinced me to go fly.. The P4 was facing the Clock. When it started to get too close (At this point the Obstacle Avoidance was clearly not working) i did a 100% pull-back and away control command that was completely ignored by the aircraft until after the P4 made contact with the clock lens , where it then descended down the post to the concrete, where it decided to shoot-off backwards (full-vertical-tilt), into a concrete/brick wall which it bounced off of and tumbled over until finally tasting dirt and getting stuck. I haven't figured out how to upload a flight log yet, but I did find it and carefully studied the timeline, commands and resulting flight. It clearly shows my CSC to pull-back and away, and shows the UAV completely ignoring the command, then losing control on contact. This was clearly a malfunction. I would be the first one to say it was my fault if I wasn't the one holding the controller, but I know I pulled back and I also know the aircraft didn't. It's not the first time I've made a CSC for the aircraft to move, and it ignored the command - I figured it was something I did, since it didn't happen again, until this incident. No one was harmed; no property (other than the aircraft and my dignity) was damaged. The battery ejected (i presume once it hit the wall) which was found only 3 feet from the LZ. Two props were trashed, the others might make good spares at best. The body sustained permanent damage to one of the arms. The damaged arm I can only presume was bent to the point of creating a "crimp" in the arm and also caused the shell to pop-out and over it's casing guides (I had to use a standard screwdriver to re-open the casing enough for the body to pop over the casing guides and back into place). One of the motors has been damaged enough to produce a light, barely detectable, noise - when compared to the near silent whistle of finger-spinning the motor, this one has an additional noise. The wire-mesh of the under-arm (a vent?) was "mushed" inward. One of the 4 Antenna Connector Covers went MIA and was recovered later - (these things fall off easily BTW). The system now reports that the Forward Sensors need calibration, and are now non-functional (as they seemingly were before) - I don't know how to re-calibrate them. After a detailed inspection and feeling confident that the aircraft would still fly, I ran some tests. First, with the props off, just to make sure the motors weren't going to explode or do something else equally fascinating - they did not show signs of concern, but I'm quite sure the impacted motor should be replaced. Then some low-altitude backyard control tests. The forward sensors won't work at all, there is a constant warning informing me they need re-calibration. Generally, it seemed to fly okay. My trust in the product is greatly challenged by the fact that it completely ignored a critical command that would have prevented the incident, and after making contact, the aircraft shot off in a direction at an uncontrollable speed. It should have shut down or at least tried to regain its level. I would have posted yesterday (the day of), but my computer's OS crashed, then the HDD crashed and is now undergoing a recovery process. I also wanted time to think this over, examine the flight log thoroughly, and "cool-off" before posting (this would have seemed a lot angrier yesterday). I will post some photos of the aircraft and flight log soon. I will consider posting the video after I investigate and can confirm that the clock is still working and completely undamaged. I would like to post the video of the flight recording that shows the CSCs along with the flight , just as it does in the app; any thoughts on how to do this? I would like to hear from DJI Support regarding this, and also from anyone else that has has their aircraft ignore a CSC. Information on how to go about re-calibrating the forward sensors would be swell. EDIT: I will be testing the clock for any frequency emissions (magnetic emissions would affect its directional awareness, not likely its communication with the controller); Frequency emission is the only possible thing i can think of that would cause the UAV to completely ignore the controller. Thanks, and Fly-On Banana Spider One Bravo Delta Niner.