What cabin altitude value triggers the red CABIN ALT alert?

What cabin altitude value triggers the red CABIN ALT alert?

• A. 9,000 feet
• B. 10,000 feet
• C. 11,000 feet
• D. 12,000 feet

Answer: (B)

When you see the red CABIN ALT alert, it means the cabin pressure is no longer being maintained at a safe level and the aircraft is at or approaching conditions that could compromise air quality inside the cabin. This warning is linked to a specific cabin altitude value, which for the CRJ‑550 is ten thousand feet. Reaching that threshold signals a potential pressurization problem—such as a leak or a failed outflow valve—and prompts immediate crew action. Understanding cabin altitude helps: the cabin is supposed to stay within a breathable range even when the airplane is flying at high outside altitudes. If pressurization can’t be maintained, the cabin altitude climbs toward that ten thousand feet mark, and the alert fires to indicate you must descend promptly to a safer altitude and use oxygen as needed. This is why the ten thousand feet threshold is chosen—the red warning emphasizes the urgency of returning to a lower altitude where supplemental oxygen can ensure passenger and crew safety.

When you see the red CABIN ALT alert, it means the cabin pressure is no longer being maintained at a safe level and the aircraft is at or approaching conditions that could compromise air quality inside the cabin. This warning is linked to a specific cabin altitude value, which for the CRJ‑550 is ten thousand feet. Reaching that threshold signals a potential pressurization problem—such as a leak or a failed outflow valve—and prompts immediate crew action.

Understanding cabin altitude helps: the cabin is supposed to stay within a breathable range even when the airplane is flying at high outside altitudes. If pressurization can’t be maintained, the cabin altitude climbs toward that ten thousand feet mark, and the alert fires to indicate you must descend promptly to a safer altitude and use oxygen as needed. This is why the ten thousand feet threshold is chosen—the red warning emphasizes the urgency of returning to a lower altitude where supplemental oxygen can ensure passenger and crew safety.