Three times now, I've had uncontrolled descents where it's like the motors are idling but I cannot regain control. Each time this has happened, I've been in close range (less than 100' away) and at modest altitude (50' or lower). The Phantom just starts coming down fast and I cannot control it. This has happened in both GPS and Atti modes (the third time I switched to Atti during the descent to see if I could regain control). Moreover, I'm not rapidly descending when this has occurred... in fact one time was during slow forward flight/hovering. This does not appear to be a flyaway issue. The motors simply run at idle speed until impact. Luckily so far, my only damage is a single broken prop. However, I'm very concerned as to what the heck is going on. I have flown plenty of times with no issues outside of what is operator error. Basic configuration: Phantom 2 Vision running firmware 3.04 Battery has been over 50% both times when this has happened; no warnings etc. WiFi is not interrupted; video can record normally even during crash! I have a RotorPixel gimbal installed but have no reason to think this is the problem (however I have removed it and will test without it on). I've opened the shell and all solder joints look fine and intact. Again, I'm not losing power, it just goes into idle. Your thoughts?