All Engines Go Around from runway well below Vref
B737-Classic Recent simulator exercise. Heavy landing and bounce and delayeed action by startled PF means airspeed below Vref by 15 knots by the time the thrust levers are fully opened up and N1 reached GA thrust or more. Flap 40 Vref was 130 knots.
As this situation is similar to stall recovery with ground contact imminent, what is the minimum speed the flaps should be retracted from Flap 40 to flap 15 assuming the gear is still down and the aircraft has attained a positive rate of climb? No windshear - just a ballsed up landing requiring a GA.