The Amphibious Benson Gyrocopter
The Benson Gyrocopter from the 1970's was one of the first mass production gyrocopters and came with an amphibious version. It came as a kit or a set of plans. Using a second small motor at the masthead to turn the rotor, it could be snatched off the water when the blades were revolving fast enough but woe betide you if you did not have enough forward speed on by that time to keep them turning and stalled out!
Our gyrocopter was built in the UK. When we got it, much was missing but it did come with a huge box of spare parts, wheels, aluminium tubing and engine bits. Our thanks to Guy for this one. He and some other RAF chaps were going to complete it but time and overseas postings got in the way. That was probably just as well because when we tried the new pistons in the engine, the heads were too deep and the engine could not turn!
He had got it in 2001 as a partly completed machine. As far as we know, it was never flown under engine power but things we have seen indicate that it might have taken to the air towed behind a car at some time before it was upgraded by having an engine fitted.
gyrocopter engineThe motor looks like an old air-cooled VW Beetle1600cc, that was rebored to 1800cc. The work having stopped at that point and hence the box of spares.
The kits and plans for these Benson gyrocopters came in several stages to permit owners to upgrade as time and money became available. The plans even showing someone apparently casually driving one along the road!
Our model has the special second motor masthead attachment but no floats yet - but it will soon have!
Due to the difficulties of getting airworthiness certificates for such an old machine, this will not fly but remain as a superb heart stopping exhibit. Adam Soloman has made a great restoration of this gyrocopter for us including a brilliant paint job.
Gyrocopters fly by the propeller at the back pushing the machine forward at speed. Before starting, the pilot reaches up and starts the twin blade rotor turning and as the speed builds up, it spins faster and faster, each blade having a lifting aerofoil profile. When turning fast enough, they are tilted to give lift and up she goes.
They can land almost vertically and have an amazing short field take off - especially if they have the small masthead motor fitted. On some models (including this one) there is a pulley from the engine that could be used with a crude clutch and rubber belt to turn the rotors for starting instead of the pilot spinning them.
Gyrocopters cannot hover like a helicopter as they need the forward speed to fly. Unlike a helicopter however, they can fly slow and low to the ground without stirring up a huge cloud of dust. Some claim this should make them an ideal covert insertion craft. James Bond used a gyrocopter code named 'Little Nellie' in the film 'You Only Live Twice'.