Thanks Djpil, almost forgotten Appendix A.
The concern for me is that, in Australia, both CASA and ATSB, after many years, still promote this potentially dangerous misunderstanding.
ATSB investigators and CASA FOI's should know better.
Having said that, any seach for Va info on the web will produce mostly incorrect information.
While the FAA airworthiness standards people have been somewhat active to correct misunderstandings, I don't think this is the case for their GA operations people.
I think the AA flight 587 A300 fin separation gave the airlines and FAA airline operations people a reality check.
At least you can ensure your students get the message!
Cheers