So a heavy B-737-400, e.g., 119,000 pounds, has a minimum maneuvering speed of 180 knots, at flaps 10?. To fly any slower would require that the landing gear be extended prior to any flap setting greater than 10? of flap being selected (or the gear warning sounds continuously and cannot be silenced).

The minimum maneuver speed on a Boeing 737 is not a single fixed number; it is a dynamic value that depends on the aircraft's weight, altitude, and flap configuration. For a "clean" (flaps up) configuration at typical weights, the minimum maneuver speed is generally around 210 to 220 knots. On the pilot's Primary Flight Display (PFD), this is indicated by the "top of the amber band" on the airspeed tape, often called the "Minimum Maneuver Speed" or "Amber Hook." This speed provides a 1.3g (40-degree bank) margin above the stick shaker stall speed. As the pilot extends the flaps, this minimum speed decreases: at Flaps 1, it might drop to 190 knots, and at Flaps 5, to 170 knots. In 2026, 737 pilots are trained to stay above these "bugs" during turns to ensure they maintain sufficient aerodynamic lift. If the aircraft's weight increases—due to a full passenger load or heavy fuel—these minimum speeds will shift higher, requiring the crew to maintain more velocity to safely execute maneuvers without triggering stall warnings.