Flying robots?

[Tristan Lall]

Originally Posted by EricH

There's a difference between flying and having the ground repel you.

Helicopters (rotary-wing aircraft) are generally more maneuverable than airplanes (fixed-wing aircraft). This allows them to fly into tighter spaces than almost any airplane. There is no comparison between the maneuverability of a 45 kg helo that is designed to fly at 45 kg (little/no payload) and that of a 10-20 lb plane that's carrying up to 4x its own weight, and is rather underpowered. The helo will win a maneuverability contest every time given that both pilots know what they're doing.

Actually, ours was a 45 kg fixed-wing aircraft (something like 35 kg empty, plus 10 kg tested payload¹). Some of the other competitors used helicopters; ours was the largest plane.

The one that crashed was on the small side—probably around 5 kg. The heaviest aircraft at the event was a Yamaha RMAX helicopter UAV, at 64 kg empty, with probably 20 kg of payload.

The smallest helicopters were intended to actually try to enter buildings (insanity, given their level of sophistication). The medium-sized ones flew right up to windows, and launched remote vehicles in. The big one (the RMAX) hovered and dropped a boom on a cable down to window level, then stuck it through the window. Ours dropped a rover by parachute, which launched a smaller remote vehicle through the window. None of these systems worked very well, and most could not be successfully demonstrated.

¹ I suspect maximum takeoff weight would have been considerably higher, given a long enough runway. We only tested to around 10 kg payload, because that's all we really needed, and because the straight portion of our testing runway was 260 m long (and uphill), and we needed to be able to reject a takeoff with moderate ease, as well as land there with payload onboard (in case of a release failure). Given time to accelerate down the 1 100 m runway at the competition, we likely would have been able to lift much more. The problem would have been maximum landing weight—taking off at 80 kg gross weight might have been feasible, but landing would have required jettisoning a large portion of that.