Is this possible? A bunch of flight instructors, CFI students and CFII students were stumped today when we were all looking at a graph that if I remember right shows the relationship between stalling speed and g-forces. The Graph shows that it is possible to stall while pulling negative G's. Or maybe that the stalling speed of an aircraft becomes negative when pulling Negative g's. Can someone explain this to me? If it is possible to stall while pulling negative G's, then how could it be done? We figured that since we all fly around in C-172's, that it would be damn near impossilbe to do for us, but maybe not for fighter pilots. What about pushing the plane over to quick into a dive? Or perhaps diving fast into critical velocity, so fast the the wings cannot produce clean lift? Can someone help me out?

Not to be mean, but I find it kind of sad if your instructors couldn't explain that to you :)

You probably know that when an aircraft stalls it is because the angle of attack becomes so high that the airflow starts to separate from the top of the wing and the wing is stalling.
When pulling negative G's, you will have negative angle of attack and this separation is just from the bottom of the wing. It is probably easiest for you to imagine this if thinking of an aircraft flying level inverted and therefore subjected to -1 G. (Every thing is just reversed)

With an asymmetrical profile the separation will happen earlier with negative G's compared to positive G's

Thats what theyt figured, but werent sure. Its kind of hard to fly inverted and level in a Cessna. But thanks for the input.