- Airflow over the wing is disrupted such that it loses lift. Contrary to common belief, this can happen at any speed (high G turn can make a plane stall) but is more common at low speed.
"Deep" or "Super" stall:
- When a plane in a stall condition has a T-tail the stabilizer can fall into the jetwash of the wing. Thus there is no airflow over the stabilizer, and no stabilizer authority. This makes recovery tricky at best.
- When airflow through the engine compressor is disrupted. In many ways the same as a wing stall but for engine compressor blades.
"There are no stupid questions, but there are a lot of inquisitive idiots."