When thrust levers are advanced to takeoff, the cabin pressure changes toward the scheduled cabin pressure at a rate of change of how many ft/min?

When thrust levers are advanced to takeoff, the cabin pressure changes toward the scheduled cabin pressure at a rate of change of how many ft/min?

• A. 100 ft/min
• B. 200 ft/min
• C. 300 ft/min
• D. 400 ft/min

Answer: (C)

When you advance the thrust levers to takeoff, the pressurization controller starts moving the cabin toward the scheduled cabin pressure at a controlled rate. That rate is set to be fast enough to reach the target early in the climb but gentle enough to keep passenger comfort and structural limits in mind. For this airplane, the rate is 300 feet per minute. So the cabin altitude climbs toward the scheduled value at about 300 ft/min, balancing quick pressurization with a smooth pressure change. A slower rate would keep the cabin at a higher pressure (lower altitude) longer, causing longer exposure to higher differential pressures; a faster rate could produce an uncomfortable or excessive rapid change in cabin pressure.

When you advance the thrust levers to takeoff, the pressurization controller starts moving the cabin toward the scheduled cabin pressure at a controlled rate. That rate is set to be fast enough to reach the target early in the climb but gentle enough to keep passenger comfort and structural limits in mind. For this airplane, the rate is 300 feet per minute.

So the cabin altitude climbs toward the scheduled value at about 300 ft/min, balancing quick pressurization with a smooth pressure change. A slower rate would keep the cabin at a higher pressure (lower altitude) longer, causing longer exposure to higher differential pressures; a faster rate could produce an uncomfortable or excessive rapid change in cabin pressure.