'Heelicopter' - Pioneering with Igor Sikorsky
'...efforts were being made to better understand the behaviour of a helicopter main rotor blade during a normal complete flight sequence...
'...it ended up with a movie camera being mounted on the hub of an R-4. I shall never forget the first time the results were shown to a small gathering of those of us directly associated with rotor problems. There was the usual amount of chatter as the room was darkened and the camera started, but it soon died out, for the gyrations that the rotor blade was going through were almost unbelievable. Especially when sudden applications of control inputs occurred, when the blade would act like a flexing fishing rod with a lively 40lb fish on the end of the line. There was also the concertina effect on the rear two-thirds of the fabric covering of the blade as it passed through its advancing and retreating cycles. However, when steady forward flight was being maintained the blade acted as thoug it was performing to the rhythm of a beautiful waltz, only to be wrenched aside without mercy when made to perform like a 'whirling Dervish' as it suddenly changed course. When the film came to its abrupt ending, there as total silence; then unmistakably, there burst forth from Michael Gluhareff: 'MUH-MUH-MUH-My-i-iiii!'
Fascinating book by William E Hunt, an engineer on the advanced design staff of the Sikorsky Engineering Dept from 1939. [That's not a misprint in the title - it's how Igor sounded.]
[Edited for typos]
Last edited by Hilico; 19th March 2006 at 20:34.