Indoor flying can be hazardous, to say the least. Obstacles, debris, and prop-wash are all very dangerous. Here, more than anywhere, is where it's important to go very slowly.

Before you begin your flight, you'll want to check for items that could get blown about. If you can't run a leaf blower in the room you're flying in … you can't fly. Indoors, I've lifted and flung area rugs across the room, seen ancient dust bunnies come out of the woodwork, and had papers shredded in my blades. I learned the hard way to do this check before I fly indoors.

You'll also want to consider possible air currents. Stay away from the walls. You'd think that walls would create a buffer of high pressure and push you away. The opposite is true. The closer you get to a wall, the more it tries to suck you in towards it. The same goes for ceilings too. Any obstacle can create a wind current. Analyze the room, and try to predict any wind currents that could disrupt your flight.

Finally, remember that you don't have a GPS signal. The gyros and accelerometers are doing all of the heavy lifting here. The barometer can't even be fully trusted, and compasses can be thrown off by the EM (electromagnetic fields) generated by appliances or even the structure of the building itself. You're going to drift, so vigilance is crucial. If you're flying from the indoors to the outdoors, remember that your GPS will reconnect as soon as it's able to. For this reason, take your multicopter outside and calibrate the compass; let the GPS lock before you bring it inside. Do this right outside the door/window out of which you'll fly out. If you don't, your guidance system will think that you've drifted far away from where you had your last GPS lock, and it will try to correct this. This will cause a huge bump in your footage, and possibly a crash. Whenever possible, fly in from the outdoors and reverse the footage (in the editing) instead to completely eliminate this risk.