Altitude

This only comes into play only on the sUAS. The propellers and the wings are severely affected by altitude. There is not a problem of being up to 400’ AGL (above ground level). The problem is the altitude above MSL (mean sea level). The thin air is very detrimental to the performance. A fixed wing drone can lose about half of its flying time when flown at 10,000 feet versus flying at sea level. There is a bit of a double whammy on the fixed wing because it has 2 problem areas, the propeller and the wing. For multi-rotors and fixed wing, it is helpful to put on a propeller which is bigger in diameter or larger in pitch or both in order to grab more of the less dense air.