deep stall

 

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deep stall

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deep stall (plural deep stalls)

1. (aviation) An extremely dangerous type of aerodynamic stall (sudden loss of lift caused by airflow separation) where the angle of attack of a T-tailled aircraft becomes so high that the horizontal stabilizer and elevators are blanketed by the turbulent wake of the main wings, rendering the stabilizer and elevators ineffective and often preventing recovery from the stall.
   • 2014 May, Rebecca Wallick, “Seventeen Seconds in the Life of a Boeing Experimental Test Pilot”, in Seattle Magazine‎^[1], archived from the original on 31 January 2021:

     And even though my father had learned from past experience to watch this particular FAA pilot closely because of his tendency to pull back too far on the control column, Dad said he was still taken by surprise when the guy abruptly pulled back so hard that the 727 entered an extreme angle of attack—70 degrees rather than the usual maximum of 25 to 30 degrees—what an aerobatics pilot would do to start a snap roll or a spin. Suddenly, unbelievably, they were in a deep stall.