How high does the Airbus A380 fly?

The largest passenger aircraft in service is certified up to 13,100 metres (43,000 ft), but it rarely occupies that level. On a typical transoceanic leg it enters cruise at around 10,600 metres (35,000 ft) and ends the flight around 12,200 or 12,500 metres (40,000 or 41,000 ft). The reason is weight: with full tanks, the airframe cannot sustain efficient flight at high altitude, and only once it has burned off dozens of tonnes of fuel does climbing become worthwhile.

That ascent is not continuous but happens in steps. Air traffic control assigns flight levels separated by three hundred metres (1,000 ft) according to direction of travel, within the reduced vertical separation scheme that applies above 8,800 metres. The crew requests a level change when the flight management system's calculation shows that the optimum altitude has risen, and the controller grants it if traffic allows. On heavily used corridors such as the North Atlantic or the Persian Gulf, that request can take a while to be approved.

At high altitude thin air reduces drag, which saves fuel, but it also narrows the margin between the minimum speed needed for lift and the upper limit set by compressibility. That margin, which crews jokingly call the coffin corner, shrinks as altitude increases. Combined with the pressurisation and structure required for a double-deck fuselage, this explains why the A380 does not exceed the ceiling of its competitors despite its size.