IvanK, thank you very much for your input, agrees totally with my limited experience of flying relevant types (Chipmunk and Harvard).
The last thing i wish to do is cause a 'war' over this (or any other issue) and further overload Ilya and the team, however at the very least it is inconsistent with the behaviour of other nations asi's.
anyway for those who want to know a little more how pitot systems work and their errors maybe of interest
http://www.nar-associates.com/techni...ide_screen.pdf
or for the more technical
http://ntrs.nasa.gov/archive/nasa/ca...1993092348.pdf