Which pressurization system unpressurizes until a preset cabin pressure is reached, then maintains a constant cabin pressure until a selected differential is attained?

Which pressurization system unpressurizes until a preset cabin pressure is reached, then maintains a constant cabin pressure until a selected differential is attained?

• A. Isobaric
• B. Isobaric Differential
• C. Pressurization
• D. Rapid Decompression

Answer: (B)

The main idea here is managing the cabin in a way that controls the difference between inside and outside pressure. In an isobaric differential mode, the system first allows the cabin to unpressurize toward ambient by dropping the cabin pressure to a preset level. Once that preset cabin pressure is reached, it then maintains that cabin pressure constant while the outside air pressure continues to fall during ascent, so the pressure difference between the cabin and the outside increases. The system keeps the cabin pressure steady until the chosen differential limit is reached, at which point the differential is controlled to stay at that target. This approach contrasts with simple isobaric control, which would keep the cabin pressure fixed regardless of how the outside pressure changes, and with rapid decompression, which is an emergency abrupt loss of pressure. The term isobaric differential specifically describes a mode that uses a fixed pressure difference as the controlling parameter, rather than a fixed cabin pressure alone, which is why it best fits the scenario described.

The main idea here is managing the cabin in a way that controls the difference between inside and outside pressure. In an isobaric differential mode, the system first allows the cabin to unpressurize toward ambient by dropping the cabin pressure to a preset level. Once that preset cabin pressure is reached, it then maintains that cabin pressure constant while the outside air pressure continues to fall during ascent, so the pressure difference between the cabin and the outside increases. The system keeps the cabin pressure steady until the chosen differential limit is reached, at which point the differential is controlled to stay at that target.

This approach contrasts with simple isobaric control, which would keep the cabin pressure fixed regardless of how the outside pressure changes, and with rapid decompression, which is an emergency abrupt loss of pressure. The term isobaric differential specifically describes a mode that uses a fixed pressure difference as the controlling parameter, rather than a fixed cabin pressure alone, which is why it best fits the scenario described.