>>If 4 is good, 54 must be great:
>>
>>http://www.theregister.co.uk/2015/09/04/quinquaquadcopter/
>
>Guess there aren't too many ways of getting airborne for £6k (unless you count a hovercraft) :-}
>
>And controlling 54 rotors in a way that provides stability and control must be a bitch.
>Nice to see that he's included the obligatory British umbrella though......

For roll, vary the power to rotors at the left and right sides. For pitch, rotors to the front and rear.

As the article says, yaw is a problem. I don't know how "conventional" small quadcopter drones do it. I imagine they have counter-rotating props so at level, steady altitude and bearing there's no net torque. They're typically small enough to have a small polar moment of inertia. So, it might be possible to yaw by varying the power/torque to the sets of counter-rotating props - more to one set and/or less to the other.

Mr. 54 has a high polar moment of inertia. That might be addressed by mounting more rotors tangentially around the rim. Another option would be to put vanes below the craft, in the downwash of the props. They could be servo operated to deflect the downwash one way or the other.

Of course, it was only a matter of time before someone took advantage of the superior energy density of Jet-A: http://www.quadhangar.com/jetquad-jet-engine-powered-quadcopter/

Thrust/weight ratio better than 3:1!