Perhaps we should be looking into advancing the propulsion systems of MAVs, small UAVs by using magnetic propulsion to spin the propellers. When testing a UAV by trying to fly it under the canopy of trees or around sparsely populated tree areas or in cities with streets and housing we may find we have difficult issues. If the aircraft as proper angle of attack you might be able to slow it down, reverse the propeller spin, do a level flight tail slide, reverse the propeller again and fly right ou.