Safety margin 2, 4, 6K or not at all ??
Thomas,
I do agree with your comments, but think that the safety margins depends on type of heli and CoG configuration.
I remember that there was a case of a Puma losing many thousands of feet before recovery (even more than 4K if I remember well), so full blown VRS here, no thanks...
Personally I think that the R44's relatively large horizontal stabilizer at the rear of the fuselage combined with small body inertia helps to create a nose down attitude (even without cyclic input). A B-206 does not do it that easy in my experience.
All comes down to making a balanced risk assessment in the teaching curriculum, see for example the fact that EC fenestron failures need not be practiced any more, because of unfavorable risk comparison.
d3