I'm thinking Bell47 or any type that could suffer a mast bump.
In Oz, flying a sailplane, I once encountered a thermal so strong it tipped my glider damn near vertically 90degrees nose down. Not sure if it was a massive up gust under the tail or a similarly massive down gust as I left the thermal but it pitched the glider dramatically.
I might not be around if I'd gone through that air in a helicopter - good reason to stay relatively low level agl where thermals haven't had time to gather much upward velocity. I was probably 4000 - 6000 feet agl on a very strong thermic day in north-west NSW.
The reason I brought up the original question is because my fixed-wing hours far exceed my rotary hours. I am confident in judging what conditions would be uncomfortable in a fixed-wing but I still use a much larger safety margin in rotary.
Interesting comment that a high speed fixed-wing aircraft like an exec jet [higher wing loading] suffers less from turbulence. If that is true - could the small surface area of a helicopter blade equate to high wing loading and thus less response to [slow] gusts?
oow
Last edited by outofwhack; 12th Dec 2012 at 14:32.