Technically this is the so-called 'stall speed', where air passes over the wings fast enough to sustain altitude, and for small planes this can be less than 50km/h (31mph). But at such low speeds, the aircraft is easily destabilised, and could fail to leave the runway.

The minimum speed a plane can fly before it "stalls" and loses lift is known as its stall speed (VS​). This number varies wildly depending on the aircraft's weight, altitude, and "configuration" (the position of flaps and slats). For a typical 2026 commercial airliner like a Boeing 737, the stall speed at landing is roughly 110 to 120 knots (approx. 130 mph or 210 km/h). However, if the plane is at a high cruise altitude (e.g., 35,000 feet), the air is thinner, and the stall speed increases significantly. Conversely, a small training aircraft like a Cessna 152 can fly as slow as 43 knots (50 mph) before dropping. In 2026, advanced "Fly-by-Wire" systems prevent pilots from accidentally reaching these speeds by providing "alpha floor" protection—automatically increasing engine power if the speed drops too low. The absolute lowest speed for any fixed-wing flight is achieved by specialized STOL (Short Take-Off and Landing) planes, which can sometimes maintain controlled flight at speeds as low as 25-30 mph in a headwind.