How fast does the a320 go?

The A320 family is certified with a maximum operating Mach number of 0.82, and airlines normally plan around Mach 0.78, roughly 830 km/h (450 kn) true airspeed at 35,000 ft (10,700 m). The gap between the two is deliberate: the wing is efficient well below its limit, and the last few hundredths of a Mach number cost fuel out of all proportion to the minutes they save. Crews reach for higher speeds mainly to recover a delay or to meet a slot, and the cost index loaded into the flight management system decides where in that band the aircraft actually flies.

Three speeds describe the same flight. Indicated airspeed, what the pitot system measures, falls with altitude as the air thins; a typical climb is flown near 300 kn indicated, which is already far more in true airspeed by the time the aircraft levels off. True airspeed is movement through the air mass, around 450 kn in cruise. Ground speed adds the wind, and on a European rotation a strong westerly can swing it by 150 km/h between the outbound and the return leg.

A short-haul A320 rarely spends long at its cruise Mach. On a 500 km sector it climbs for twenty minutes, cruises briefly and begins a descent flown at idle thrust, and below 10,000 ft air traffic control caps it at 250 kn indicated. Taxi at both ends, holding and speed control on the approach add more. The result is an average block speed far below 830 km/h, which is also why trimming cruise Mach to save fuel costs far less time than passengers tend to assume.