Highflyer wrote:
"cavelamb himself" wrote in message
...
All it takes is a little collar on the pitot tube (and a bit of tweaking
the position) 
That is how we calibrate the airspeed indicator to get it reading with
reasonable accuracy. Old CG himself taught me that one. :-)
Of course, nowadays, you have to tweak the GPS also!
Anybody have photos of such a collar? Or able to give a good description?