It was a bit of a surprise for me to hear that Vne would be based on TAS rather than IAS. I would have said what the other CFI told you ... that your Vspeeds are about the molecules of air hitting the airframe and therefore should be based on IAS and not TAS. However, after a bit of research I believe that the above is true for all Vspeed except Vne and it may have something to do with the difficulty in establishing a Vne speed due to the several different types of limitations that may be factors when determining that number. For an interesting discussion on this have a look at this builders forum post -
http://www.bluemountainavionics.com/tal ... .php?t=629
Anybody else want to chime in here?
"To Live is To Fly" - Townes VanZandt