John Bishop’s Whirlgig Autogyro Thing

John has sent over an update on his Whirlygig autogyro project which some of us will recall from its erratic if not entertaining take off procedure, but which is nonetheless an awesome if not slightly puzzling (ie how does that work?) flying machine.

John reports that:

After a rather hairy test flight performance is much better now since I replaced the earlier 3-bladed rotors with a 4-bladed set.  Stability and general handling are much improved.

Which is a good thing!