How fast do passenger airplanes fly?

An Airbus A320 or a Boeing 737 cruise at Mach 0.78-0.79, about 830-850 km/h true airspeed at 11,000 m. Long-haul aircraft are somewhat faster: the Boeing 787 and Airbus A350 fly at Mach 0.85 (about 900 km/h) and the Boeing 747-8 at Mach 0.855. These figures are expressed in Mach number because, at high altitude, what limits the design is proximity to the speed of sound, which at that altitude and temperature is around 1,060 km/h. Above Mach 0.86, drag rises sharply due to local shock waves forming over the wing, and fuel consumption spikes.

The speed that matters to the pilot is airspeed, the aircraft's speed relative to the surrounding air. Ground speed, the one passengers see on the cabin screen, adds or subtracts the wind: with a tailwind from the jet stream, a flight between New York and London can exceed 1,100 km/h over the ground without anything changing on the aircraft. In the opposite direction, the same route takes an hour longer. That is why transatlantic schedules are not symmetrical.

On takeoff, a single-aisle jet rotates at 250-290 km/h (135-155 kn), and on landing it approaches at about 250-270 km/h and touches down a little slower. A regional turboprop such as the ATR 72 cruises at about 510 km/h (275 kn), enough on legs under 600 km, where most time is lost on the ground. Concorde, retired in 2003, cruised at Mach 2, about 2,150 km/h; no passenger aircraft in service today comes close to that figure again.