I have built it ages ago, in elementary school. It was a Russian transport or passenger helicopter, with two propellers, one forward and one aft, similar to Chinook but I think it was longer and nerower. Any ideas?
Thanks…
Yak-24 ‘Horse’?
Andrew
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Did it look like this beast?
Thank you gentlemen, Yak-24 it was.
Cheers…
I’m not 100% sure about these facts but some years ago I was reading one of my Aircraft/Helicopter books and it mentioned that during the development and testing of the Yak-24 tandem rotor helicopter , during each test flight the fuselage would vibrate so violently that some test flights would only last a few minutes .
Every time they strengthened the airframe it would vibrate just as bad in another section .
This issue went on during each test flight that eventually out of frustration one of the helicopter technicians said “why dont we cut 12 inches of the end of each rotor blade” . Nobody thought this would make any difference , however on the next test flight the helicopter fuselage did not vibrate at all and everyone suddenly realized that the problem was the rotor blades were just too long to start with .
I’ll try and find the time and see if I can find the article amoungst my books .
John .
I found the book the article on the Yak -24
It seems that the vibration problems were a major issue for all of the early tandem helicopters , they actually cut half a meter from the tips of the rotor blades .