Originally posted by: ChAoTiCpInOy
We all know that they equalize the pressure between the outside and inside at ground level so when the plane is at cruising altitude they are able to breathe normally. Why is it that even with this equalization of pressure your ears still pop when the plane ascends.
Wikipedia:
"The pressure maintained within the cabin is referred to as the equivalent effective cabin altitude or more normally, the ?cabin altitude?. Cabin altitude is not normally maintained at ground level (0ft) pressure throughout the flight because doing so stresses the fuselage and uses more fuel. An aircraft planning to cruise at 40,000 ft (12,000 m) is programmed to rise gradually from take-off to around 8,000 ft (2,400 m) in cabin pressure altitude, and to then reduce gently to match the ambient air pressure of the destination. That destination may be significantly above sea level and this needs to be taken into account; for example, El Alto International Airport in La Paz, Bolivia is 4,061 metres (13,320 ft) above sea level."