Sloping Off - June 2005
The Autogyro and the Bear
by Brian Wiseman
Many years ago when I was about 7 years old I saw an Autogyro fly at our local Airshow. The plane intrigued me. Now I am of more mature years from time to time I have considered trying to make a model one. About five years ago I saw someone try to get one off the ground and It never left terra firma as it gained speed it tipped over to the left and fell over. Last year I read an article about these planes and it said that unless you can get the blades spinnIng very quickly you have trouble. The trouble is this. If you imagine a rotor spinning at 10 mph and you are going forwards at 10 mph. The forward blade will be generating lift from a combined speed of 20 mph. The blade going backwards will be in dead air and have no lift at all. So it will tip over.
Being a thoughtful sort of chap I wondered what would happen if we had two blades, each going round in different directions. The one going backwards would be countered by the one going forward. If we had contra rotating blades the plane would be so confused that by the time it had worked out the aerodynamics it would have leapt into the air, and started flying. Some of you electric bods may find this too technical.
So I decided to invent one. I am very good at decisions like this. The idea remained between my ears for some time. Then I thought, I bet someone else has had the same idea, and so they had. Mr Alex Weiss had designed, refined and built one which had flown. Eventually I obtained the plans. I looked at them wIth horror. I am much better at thinking about inventing things than I am at actually inventing them. I could see that I could easily make the fuselage from the plan, but the rotors and the shaft had to be so precise that it was beyond my limited skills.
Being a resourceful kind of chap I mentioned this problem to a friend of mine, Dennis Cross, who is a superb builder and he thought the idea was most interesting. A month later I took delivery of the Al’s Autogyro.
The pilot is a Bear. He has just come from piloting a twin Panavia so he is used to flying. His Panavia came down because one of the engines stopped. He and the co pilot were found out of their seats at the back of the cabin. He has no sensible explanation for being there when he should have been flying the plane. I think they had been fighting, so I hope he can control himself in this one.
The big day came. I had put in a 46 four stroke O.S.Engine. Ian Hammond tried it first and it did sort of take off and it did go up. It staggered along towards the cars (this was at Beaulieu). Ian tried to turn it away and it sort of side slipped to a hard landing which dented it somewhat. Dennis was there and he offered to put it right. The next time I tried to get it off the ground but it kept tipping over to the left. The Bear got fed up with this so Ian had a try and after several tips over he managed to get it airborne but it was obvious from the way it staggered along that the engine was not up to it. He managed to put it down into a gorse bush and it was undamaged. Being a determined sort of chap I then put in a 60 A.S.P two stroke. This is a man’s engine not like the little sewing machines you electric bods use. I thought that I ought to try it this time. We got the rotors going and I gave it some wellie.
My theory worked. The plane tilted to the left, some up elevator and more wellie and it leapt into the air with a rather startled Bear hanging on tightly. It kept going to the left and remembering all I had learned from my Biggles books I gave it some right rudder and round she came, going up all the time. I throttled back and started to try to get it flying towards me. IT FLEW IT FLEW IT FLEW.
Then (and I can hardly bring myself to say this), sadly one of the rotors came off in mid air. You do not want to know what happened next because I was right over the concrete runway. When the spectators had dried my tears and given me a cup of tea, I had a look at the wreakage. The front was smashed and the fuselage broken but I could see it was mendable (optimist Ed). However summer will soon be here, this means grandchildren, guests, the dreaded lawn, gardening holidays etc. I guess it will be some time before It gets airborne again. The Bear was unhurt, and wants to have another go, he reckons he will be the first Bear to take off and land an Autogyro. Watch this space.
