Decompression is

Decompression is

• A. An increase in cabin pressure beyond design.
• B. The inability of the pressurization system to maintain designed cabin pressure.
• C. A temporary decrease in cabin pressure that's recoverable by normal operations.
• D. A pressure change due to altitude when cabin seals remain intact.

Answer: (B)

Decompression means the cabin loses pressure because the pressurization system can’t maintain the designed cabin pressure. It’s an uncontrolled drop, not an increase in pressure or a routine change with altitude. It can happen if there’s a leak, a seal failure, or some fault in the system that prevents keeping the expected pressure inside the aircraft. When decompression occurs, the cabin pressure falls below normal, and the crew must act to restore safe conditions, typically by descending to a lower altitude and using oxygen. The other descriptions don’t fit because over-pressurization describes too-high pressure, a temporary drop recoverable by normal ops describes a non-defining, controllable fluctuation rather than an uncontrolled loss, and a change due to altitude with seals intact describes normal operating pressure changes, not decompression.

Decompression means the cabin loses pressure because the pressurization system can’t maintain the designed cabin pressure. It’s an uncontrolled drop, not an increase in pressure or a routine change with altitude. It can happen if there’s a leak, a seal failure, or some fault in the system that prevents keeping the expected pressure inside the aircraft. When decompression occurs, the cabin pressure falls below normal, and the crew must act to restore safe conditions, typically by descending to a lower altitude and using oxygen. The other descriptions don’t fit because over-pressurization describes too-high pressure, a temporary drop recoverable by normal ops describes a non-defining, controllable fluctuation rather than an uncontrolled loss, and a change due to altitude with seals intact describes normal operating pressure changes, not decompression.