I never got airsick back in training...to the point where I puked that is. I did get queasy one hop in the T-2C Buckeye, the OCF flight. Kinda crazy so it got to me. Went on to fly straight and level (C-2A's) for 8.5 years. Been instructing in Navy primary for a year and have yet to have a student puke. It's not like the aero or g's (3-4) are tough though...loops, 1/2 cuban eights, immelman, etc so that might be the reason. I've had a few come close during aileron rolls and I sometimes feel it after 5 or 6 in a row. I did get a little out of whack on my NATOPS OCF flight in the T-34 but got used to very quickly. Most studs do the same. Those that don't may have to spend some time in the spin and puke. If that doesn't help and whatever else the doc offers, the student could be NPQ'ed for flight training.