Rapid decompression is described as which event?

• A. The gradual loss of cabin pressure over several hours.
• B. The almost instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.
• C. A minor drop in pressure during high altitude climb.
• D. A delay in pressurization system start after landing.

Answer: (B)

Rapid decompression means the cabin pressure is lost almost instantly due to a breach in the pressurized volume. In flight, the cabin is kept at a higher pressure than the outside air, and if a window, door, or structural panel fails, air rushes out rapidly. This can happen in aircraft with a pressurized cockpit or cabin and requires immediate actions like oxygen for occupants and a quick descent. The other scenarios describe slower leaks, minor pressure changes, or startup issues, none of which match the immediate, uncommanded pressure loss that defines rapid decompression.