At the same time, when the pilot felt the "bump" in the air he reflexively made large stick movements, commanding first maximum pitch down and then maximum pitch up, but while the angle of attack is above the 20° limit the control software ignores pilot commands and prioritizes reducing the pitch, so there was no response from the airplane. The pilot never realized that the plane had entered a stall and only noted that his pitch inputs had no effect, so when he saw the ground collision warning he elected to vacate the aircraft in accordance with the flight manual. The period when the angle of attack was above 20° lasted 3.2 seconds; coincidentally the airplane returned to a controllable condition almost exactly when the pilot released the stick to pull the ejection seat handle. Following this accident, Saab modified the flight control software to detect when the airplane is passing through a wake vortex and apply different control laws during the transient.