Deep stall

Deep Stall is a aerodynamic stall condition that is difficult or impossible to correct. In some flying tail aircraft it is the blanketing of the rear control surfaces by a stalled main wing. In a canard it is typically a stalled main wing, which the canard has no aerodynamic ability to nose down and correct.

The revised designs ensure that deep stalls occur only if the canard aircraft is built or operated beyond its approved limits. The most likely cause of a deep stall today is flying with the CG beyond the aft limit, either knowingly or unknowingly. Building errors that result in incorrect incidence angles on the canard or main wing can also be the cause. These issues should be identified and resolved during the aircraft’s test phase. Despite the rarity of deep stalls, some pilots express concern that unusual attitudes could alter the normally benign canard stall behavior.