The top rotor turns because of the passage of air through the rotor and the forward momentum is gained by the engine and propeller.

The Autogyro was invented, it seems, by Juan de la Cierva in 1919 and made its first successful flight in 1923.  However, in the UK our Autogyro hero is a chap called Kenneth Wallis, or to give him his full title Wing Commander Kenneth Wallis MBE, DEng, CEng, FRAeS, FSETP, PhD, RAF (Ret’d)…whew!

You will probably have seen Kenneth Wallis’ most famous Autogyro – the Wallis WA-116 but she is better known as Little Nellie and was used in the James Bond film You Only Live Twice.  Little Nellie was designed and built in the 1960’s and I think she was well ahead of her time