3 ms·

I imagine a three pound hailstone (Phantom 3 specs say 1280 gram weight) would cause some problems for a chopper.

• ryan_j_naughton 11y ago
  I think his point was that the drone is unlikely to carry much more force than hail. F = MA Thus, even though the drone is heavier than hail, it won't likely be going as fast as hail (such that its deceleration when hitting the helicopter would be less significant). Thus, the comparison is apt. If we had 3 lb hail, it would have much more force than most 3 lb drones bc of its speed.
  • mikeash 11y ago
    Hail was mentioned in the context of, "I'm assuming 'copter windscreens can handle hail?" I can guarantee you that a helicopter windscreen cannot handle 3lb hail. If such a hailstorm were ever encountered (unlikely, the record in the US is 1lb 15oz) then the helicopter would be completely destroyed. If we consider a somewhat more sane hailstone size of 8cm, that has a terminal velocity of about 170km/h and weighs about 1.5lbs. And a helicopter is not going to survive flying through a storm like that either. This drone, by comparison, weighs twice as much. The helicopter's cruising speed is about 245km/h, so that would be about the impact speed. I don't understand why anyone would think that a 3lb chunk of machinery moving at 150MPH relative to a helicopter wouldn't go through the windscreen. I also don't understand why everyone in this thread is apparently so eager to minimize the risks presented here. There are some good arguments to be made about not over-regulating and about the low probability of an actual impact, but the attempts to downplay the potential effects of an impact should one occur are getting pretty crazy.