There is no indication of who broke the 400ft level: did the drone go over it or did the chopper go below it? As for drone pilots keeping clear of aircraft, th

There is no indication of who broke the 400ft level: did the drone go over it or did the chopper go below it? As for drone pilots keeping clear of aircraft, that is only possible when the aircraft are maintaining visual contact with all drone operators on the ground. Ideally drone pilots would be able to receive smething similar to ADS-B signals and the ground control stations would all direct drones away from nearby aircraft. Sadly the resolution and accuracy of ADS-B in all four dimensions is insufficient to allow automatic avoidance of scenarios like the one posted.