What Happens When a Plane Loses Cabin Pressure: Do Pilots Wear Oxygen Masks?

When a plane experiences a drop in cabin pressure, pilots are required to wear oxygen masks immediately. The importance of this action cannot be overstressed: any exposure to unpressurized air above 30,000 feet for more than 20-25 seconds can result in a rapid loss of consciousness. Hence, as soon as the oxygen mask drops or is required, it should be immediately donned to ensure the survival of both pilots and passengers.

The cabin is pressurized to maintain the equivalent of around 8,000 feet above sea level, ensuring a comfortable and safe altitude for passengers. However, if the cabin pressure drops, the masks will automatically deploy to provide passengers with 10-15 minutes of supplemental oxygen. This is a critical safety measure that ensures that passengers remain conscious and able to follow instructions in case of an emergency.

In the cockpit, the situation is even more critical. The pilots have quick-dawning oxygen masks and portable oxygen bottles as part of their emergency equipment. The cockpit oxygen masks are not a drop-in system like those for passengers, but rather are manually activated. The pilot oxygen masks are different from those of passengers in several ways. Passenger oxygen is generated through a chemical reaction within a small container above the passenger's head, which lasts around 15 minutes. This is sufficient for the pilots to perform an emergency descent to an altitude where it is safe to breathe, typically around 10,000 feet MSL (Mean Sea Level).

Cockpit Oxygen Supplies

Pilot oxygen masks have a stark difference: they do not have a generator. Instead, they are filled with oxygen stored in a canister, which is capable of providing more than one hour of oxygen. In the event of an emergency, pilots must manually pull the oxygen mask from the compartment next to them.

Emergency Descent Procedures

With more than an hour's worth of oxygen supply, pilots can execute a rapid descent to the safe altitude. Legacy emergency procedures typically direct pilots to descend to 10,000 feet MSL as soon as possible. This is an altitude where the air is breathable, and the pilots can regain control of the aircraft.

Passenger oxygen masks, on the other hand, are not just a passive device. They are designed to ensure that all passengers are adequately supplied with oxygen during the critical initial phase of decompression. The masks for pilots, while serving the same life-saving purpose, have additional advantages due to their dedicated oxygen supply containers and longer duration.

Passenger Oxygen Mask Deployment

The moment an oxygen mask drops from the overhead compartment during a decompression, it signals that the cabin altitude has exceeded 10,000 feet. This is the point at which the airline's emergency procedures are typically initiated. Passengers should be instructed to put on their masks immediately. The chemical reaction in the passenger oxygen masks provides around 15 minutes of supplementary oxygen.

Conclusion

In conclusion, the aircraft's ability to maintain pressurization is critical, and in the event of a loss, the immediate and correct use of oxygen masks is a key safety protocol. For pilots, the process is more hands-on and requires quick action to secure their oxygen supply, contrasting with the automated deployment for passengers. Both systems, however, serve the same essential purpose: ensuring the safety of those on board.