Could well be Jim. Like I said that was what I understood.

Ian
"Jim Vincent" wrote in message
...
I understand that that is the limiting factor to helicopter forward
speed.( and why 'Airwolf' could never have worked ) At around 400 kph the
forward going blade starts to overcome the amount of control input
available

I thought is was because the forward blade is approaching supersonic.

Jim Vincent
N483SZ
illspam