how much does a blade flex?
 

we've all seen this video

http://www.griffin-helicopters.co.uk/videos/ROTOR.avi

does an R22 blade flex to the same amount?

Don't know about the R22. However, I saw a TV program that showed flexing in the prototype blades for the first Bell 47 model. It was scary to say the least. Perhaps someone can find the video on the web and give a link.

Slightly off topic, but on a similar theme, I'm after some photos of blade sailing.

the only one I can find on the net is:

http://http://www.afm.ses.soton.ac.u...esailing01.jpg

If anyone has any they'd like to pass on, I'd be grateful.

:)

'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]

Interesting pictures.
Recent advances in digital slo mo cameras have enabled portable lower cost cameras with very high frame rates and good resolution.
4000-10000 frames per second is achievable in sunlight.

Is this technology being used outside of reasearch and design establishments to trouble shoot mystery vibrations ect that could be related to rotor performance?

Ultra slo mo any use in checking that a rotor system is within specification on delivery?



Mickjoebill

I know of that film, are there any more?

That is excellent stuff.

thats awesome.freaky but awesome.
anyone tracked down the vid footage from a H500 with camera mounted at the main rotor hub and looking down one of the blades?
i have seen it before & it's wild to the point of "sh#t i am never getting into another hecktopleter again"!

Which reminds me of my first solo cross country in a Hughes 300. I turned my head and looked at the spinning rotor head which you can see clearly through the plexiglass. Is that all thats holding this thing in the sky!