At what altitude do the oxygen compartments automatically deploy on the 787?

At what altitude do the oxygen compartments automatically deploy on the 787?

• A. 12,000 Feet
• B. 15,000 Feet
• C. 18,000 Feet
• D. 20,000 Feet

Answer: (B)

Oxygen supply for passengers is designed to become available as soon as cabin altitude indicates hypoxia risk. On the 787, the oxygen compartments automatically deploy when the cabin altitude reaches 15,000 feet. This threshold is chosen to ensure masks drop promptly in a depressurization while avoiding unnecessary deployment during normal high-altitude cruise. If the threshold were much lower, masks could deploy too often; if it were higher, oxygen might not be available quickly enough when the cabin loses pressure. The 15,000-foot setting provides a safe balance, with the compartments releasing and the masks becoming accessible to passengers as soon as the system detects the rise in cabin altitude.

Oxygen supply for passengers is designed to become available as soon as cabin altitude indicates hypoxia risk. On the 787, the oxygen compartments automatically deploy when the cabin altitude reaches 15,000 feet. This threshold is chosen to ensure masks drop promptly in a depressurization while avoiding unnecessary deployment during normal high-altitude cruise. If the threshold were much lower, masks could deploy too often; if it were higher, oxygen might not be available quickly enough when the cabin loses pressure. The 15,000-foot setting provides a safe balance, with the compartments releasing and the masks becoming accessible to passengers as soon as the system detects the rise in cabin altitude.