Which cabin altitude is normally maintained during cruise on the A321?

• A. About 6,000 feet
• B. About 8,000 feet
• C. About 10,000 feet
• D. About 12,000 feet

Answer: (B)

The cabin is kept at a moderate altitude to balance passenger comfort with the aircraft’s structural limits. On the A321, the cabin altitude is normally about 8,000 feet during cruise. This means the air inside the cabin has the same pressure and oxygen level you’d experience at 8,000 feet above sea level, even though the airplane is cruising far higher outside. The pressurization system automatically maintains this by controlling bleed air and the outflow valve to hold the target cabin altitude. A lower cabin altitude, like 6,000 feet, would require a higher pressure differential across the fuselage and more stress on the structure, while a higher cabin altitude, like 10,000 or 12,000 feet, would reduce comfort and can affect passenger well-being. Therefore, 8,000 feet is the standard compromise for normal cruise.