Quadrocopter drones are everywhere, snapping aerial photos for journalists, acting as toys in kids' backyards, even delivering parcels. But watching their amazing aerial acrobatics you, like me, must have pondered how these things would fly if they were damaged. Surely they'd crash instantly. Nope. Research into fail-safe techniques at ETH Zurich have shown they can still fly even if a rotor blade breaks off in mid flight.
The trick, as you can see from the video above, is to give the quadrocopter's flight computer enough smarts so that it can keep itself stable in the air even if a catastrophe, like losing one of its rotors, happens. The damaged aircraft quickly tries to adapt to its new flight regime, which is inherently unstable because of the asymmetry between the three remaining blades. Nevertheless, it merrily copes as best it can and calmly waits at a point in the air so its controller can then land it safely.
You might think this is silly, but the science is already used in aircraft like the Stealth Bomber—a vehicle that would simply fall out of the sky if its computers failed because it's so unstable. And adaptive fail-safes are going to be critical if our skies are soon to be filled with drones zipping your dry cleaning or wedding rings around, because a drone that can still fly if damaged is better than one that zooms uncontrollably to the ground with its skin-chopping rotors at risk of hurting people. You can bet Amazon is watching this video with great interest.