23.369—Rear lift truss.
        
        (a) 
         If a rear lift truss is used, it must be designed to withstand conditions of reversed airflow at a design speed of—
    
    
         V=8.7 √(W/S)   8.7 (knots), where W/S=wing loading at design maximum takeoff weight.
    
    
        
        (b) 
         Either aerodynamic data for the particular wing section used, or a value of C
            L equalling −0.8 with a chordwise distribution that is triangular between a peak at the trailing edge and zero at the leading edge, must be used.