Ich wollte die Batterie leer Fliegen. Plötzlich wurde die automatisch Rückkehrfunktion aktiv und der Mavic flog an die Decke und stürzte ab. Warum wird in einem geschlossenen Raum, Raumhöhe 3 Meter, diese Funktion aktiviert?  Es gibt keinen GPS Empfang.

Ich bin vervundet; und kann ich nicht bewegen.  
Seriously, don't ask for help in german.  The language is english; asking in german makes you look like an ass.   
Im Ernst, fragen Sie nicht um Hilfe auf Deutsch. Die Sprache ist Englisch; Fragen Sie in Deutsch macht Sie aussehen wie ein Esel.

R.T.F.M..please

RTH can only be initiated when there is a GPS signal. This GPS signal must have been available when the drone was started, so that a home point could be recorded. The home point can be set manually. In that case the remote control (in particulr the connected smartphone) must have a GPS location.

To see what went wrong during the flight, you can open the flight log, replay the flight. You can also use a screen recorder to record your flight and make it available here.

MacIak Posted at 2017-2-16 09:27
R.T.F.M..please

The manual does not mention a RTH feature without GPS. We should wait for the flight logs to shed some light on this.

The question being asked by the OP is why the RTH function is automatically activated in a closed room.  The poster was trying to fly the battery to a low level inside the room. This is a really bad idea but let's answer the question. The answer is the Mavic has no idea it's inside and will act just as if it's outside.  When the battery gets low enough the RTH is initiated by the firmware.  The problem is if this happens indoors, there's a good chance that at some point the Mavic may have gotten a GPS signal and assigned a home point but possibly a very inaccurate home point.  Indoor GPS positions can be VERY inaccurate.  So what happens when the RTH is activated, the Mavic tries to fly to the RTH altitude and return home.  Clearly not a good situation.  (The Mavic does not have sensors on it's top so it can't sense that it is about to hit the ceiling. )  I hope that's helpful.