A very successful drone expert, Erik Navarro in Illinois, gave me advice about drone safety. He has an official FAA approved drone license and his advice is that an unmanned drone could fail and fall on a person. I have solved that by designing a fail safe flight assembly.

YOUR FLYING SIGN IS BEST WHEN ABOUT 8 FEET ABOVE YOUR ROOF

I am describing here a method for using a strong cord to pull the drone and its tether over the roof as it rises and descends so that if the drone motors or electronics fail it will fall on the roof.

The first action is to mount a pulley on the side of the house at the highest point available such as the edge of the peak of the roof. That on most homes is about 12 feet above ground. On homes with flat roofs it will be the highest point on one outside wall about 9 feet over the ground. When using this method one needs to add a strong cord that is attached to the other end or side of the roof that will allow the drone to rise up over the pulley but the cord will pull the drone over the roof as it ascends. This will assure that should the drone motors fail the drone will not fall to the ground away from the house.

The drone is tethered to the edge of the roof using an electric cord that carries power to the drone so it does not have a battery that will run out of power. The tether goes through the pulley that is attached to the side of the house. The tether is unrolled from a reel on the ground that is in a container that also contains a heavy battery and a power supply to power the drone. The battery in the container powers the drone in case AC power goes out at the house.

Safety is assured by the fact that the tether will let the drone fly higher than the top of the roof. If the drone fails and falls it will be pulled over the roof by the 2nd cable.