So today was a beautiful day out and I decided to fly the Phantom for the 1st time. Everything was fine and dandy until the Phantom started gaining altitude (without me controlling) and started veered toward my right in a fixed path until it crashed into the ground. This occurred maybe a little after 4-5 minutes of flying and I wouldn't say the Phantom hovered above 100 ft before the crash. I went home and replaced one of the broken propellers and went out again. I crashed hard this time, again. Same situation where it gains altitude before getting on a "fixed path" toward the crash. Everything is up to date...compass was calibrated (unless I should have had re calibrated after my 1st crash few nights ago that did not last more than 1 minute?) Everything seems to be in working order. The range extender was pointed toward the Phantom.... My 1st crash, there was a chopper circling around my area (like literally circling around ME as if they were interested)...could them being in the air affect the transmission between the phantom & the controller? i was at my old middle school which did not really have many power lines...but there were some. I had at least 10 satellites locked in and I waited about a minute or two confirming there was a GPS lock. When I started noticing it flying away from me where I lost connection with my iPhone, I just figured it would go into fail safe mode and fly itself back (i did not adjust S1/S2 switches at this time). As I have stated in other threads, I'm not so savvy with RC technology so I fear that I may have made a rookie mistake or something. My 2nd crash, everything was fine until I increased my phantom's altitude level to about 400 ft in the air and all of sudden it lost connection with my iPhone and started veering toward the right on a fixed path until its crash few moments later. When this occurred, the helicopter was not around at this time thus possibly eliminating the theory of the helicopter blocking communications (waiting for confirmation from you guys) so I am not sure what happened here, again. As for the motors....I can tell there is a definite amount of semi-wet dirt that is stuck inside one of the black propellers' motor thing. Any ideas if I can pop open the shell assuming it doesn't take too much wiring (unplugging and reconnecting after) to clean it out? When I twist the motors using my fingr, i can tell there is dirt underneath one of the motors because of the "bumpiness" like as if you're driving on gravel. I'm not savvy like you all when it comes to putting things together. Especially when wiring is included. I'm going to do more research this evening and hopefully locate the reasoning(s) for my hard crashes today. I really hope I can adjust this issue because the Phantom is really cool. Would be a terrible shame to see $1.2k go down the drain after two flights, haha.Thanks guys, I hope to hear some useful troubleshooting recommendations from some people here! -Anthony P.S. Really wish I didn't disable "stop recording" feature when losing connection with the power. Would have been really interesting and useful to review footage before crashe(s). Oh well!