When an aircraft is at 30000 altitude , how it maintains the pressure ?
Most modern commercial aircraft today have a dual channel electronic controller for maintaining pressurization along with a manual back-up system. These systems maintain air pressure equivalent to 2,500 m (8,000 ft) or fewer, even during flight at altitudes above 13,000 m (43,000 ft). Aircraft have a positive pressure relief valve in the event of excessive pressure in the cabin. This is to protect the aircraft structure from excessive loading. Normally the maximum pr ...more