Noticed an interesting phenomenon yesterday flying the Air 2S (I assume it would apply to all drones). I was flying in Normal mode into a clearing on a landing approach, full stick forwards and full stick descending. At about 12 feet above ground I let off the forward stick input and the drone pitched backwards to brake. What surprised me was that the drone fell like a brick for about half a second. It dropped at a MUCH faster rate than Normal mode descent. I let off the descend input, and it recovered about 3 feet above the ground and hovered.
It all makes sense in that the pitch angle on braking was very steep - it looked to be 45 degrees or more - so there was reduced upward thrust. I am pretty sure I didn't put any revers thrust input. I suppose the drone forward collision sensors may have activated (I was several feet from some trees), but I don't think so. It just looked like the drone response to the accelerated descent was delayed.
Perhaps as the drone pitched back so steeply, the downward facing sensors detected an apparent increasing distance to the ground, giving it a signal that it was climbing and it reduced the upward thrust component as I was still commanding it to descend. I assume it then recovered either when the braking finished and it naturally returned to level orientation, or maybe only because I released the descend stick input when it plummeted??
Thinking about this phenomenon, I assume it might happen when flying fast and low over flat ground, and then suddenly stopping the forward input. Potentially the drone could crash if it pitched back and dropped a few feet in the process.
If the downward facing sensors dominate the GPS for determining altitude when flying low, then this drop might occur because of the pitching back and apparent increase in distance to the ground. It wouldn't be seen when braking at higher altitude, but only low altitudes. I don't have the courage to test this theory. Is anyone aware of this phenomenon happening?
It might be particularly relevant to anyone flying low over water, as a crash in that instance would likely prove fatal to the drone.
It all makes sense in that the pitch angle on braking was very steep - it looked to be 45 degrees or more - so there was reduced upward thrust. I am pretty sure I didn't put any revers thrust input. I suppose the drone forward collision sensors may have activated (I was several feet from some trees), but I don't think so. It just looked like the drone response to the accelerated descent was delayed.
Perhaps as the drone pitched back so steeply, the downward facing sensors detected an apparent increasing distance to the ground, giving it a signal that it was climbing and it reduced the upward thrust component as I was still commanding it to descend. I assume it then recovered either when the braking finished and it naturally returned to level orientation, or maybe only because I released the descend stick input when it plummeted??
Thinking about this phenomenon, I assume it might happen when flying fast and low over flat ground, and then suddenly stopping the forward input. Potentially the drone could crash if it pitched back and dropped a few feet in the process.
If the downward facing sensors dominate the GPS for determining altitude when flying low, then this drop might occur because of the pitching back and apparent increase in distance to the ground. It wouldn't be seen when braking at higher altitude, but only low altitudes. I don't have the courage to test this theory. Is anyone aware of this phenomenon happening?
It might be particularly relevant to anyone flying low over water, as a crash in that instance would likely prove fatal to the drone.
