Pressurization is the process of increasing air pressure inside an aircraft specifically the cabin. This is done due to reduce trapped gas, decompression sickness & hypoxia which is a condition of insufficient oxygen. An aircraft flies in high altitudes because it consumes less fuel due to low turbulence, it also does so because of as said to avoid turbulence, storms and bad weather. it is therefore necessary deemed that all aircraft be pressurized.
Pressurization is drawn from engine power i.e in piston engines it is derived from turbochargers, superchargers, engine driven air pumps while in jet engines it is derived from engine bleed air from the compressor.
while the cabin is pressurized it is necessary to regulate, control the pressure and temperature this is done by :-
- heat exchanger – used to cool hot pressurized air to workable temperature.
- safety valve – prevents cabin over pressurization by opening automatically at a determined pressure.
- Outflow valve – regulates the amount of pressurized air that exits the cabin.
- negative pressure relief valve – Prevents cabin pressure from going lower than that of the ambient air.
- Dump valve – Releases all pressurized cabin air on aircraft landing.
Aircraft pressurization is a matter of seriousness, a lot of accidents have happened due to lack of pressurization in the cabin for instant if the pilot and co-pilot were to pass out due to lack of oxygen it would be catastrophic. it is capable of killing every passenger on flight due to hypoxia,trapped gas and decompression sickness.
Excessive or lack of enough pressure can also cause damage to aircraft fuselage. The aircraft windows are designed to never be opened well except the D.V window i.e direct vision window which is used by the pilot to land the plane in-case of obscurity in wind screen. it can also be used as an exit for emergency. All this is done to maintain pressurization in the aircraft.