What is the minimum supplemental oxygen supply required for each crew-member in pressurized air carrier transport airplanes?

The minimum supplemental oxygen supply required for each crew member in pressurized air carrier transport airplanes is two hours. This requirement is established to ensure that in the event of a cabin depressurization or other emergency situations where the cabin altitude rises to a level that could compromise the safety and performance of the flight crew, there is an adequate supply of oxygen to sustain the crew until the situation is resolved or the aircraft reaches a safe altitude.

A two-hour supply is deemed sufficient because it provides the crew with time to manage the situation effectively or execute necessary emergency procedures. This duration is based on industry standards and safety regulations, taking into account typical scenarios that might occur in-flight. The emphasis on two hours reflects the need for readiness and response capabilities during adverse circumstances, thereby enhancing overall flight safety.