What role does an altimeter play during an emergency descent?

The altimeter is an essential instrument during an emergency descent because it provides real-time information about the aircraft's altitude. In a critical situation where rapid descent may be necessary—such as in response to a cabin depressurization or engine failure—the altimeter assists pilots in quickly descending to a safe altitude, often below any potential obstacles or hazardous weather.

By closely monitoring altitude, pilots can ensure they are not only descending quickly but also safely, allowing them to react appropriately to maintain control of the aircraft and prepare for further actions as necessary. This capability of the altimeter to show altitude helps define the vertical profile of the emergency descent and can guide the pilot in making decisions that follow regulatory or safety protocols.

While other functions, like obstacle avoidance or fuel monitoring, are essential aspects of flight management, they are not the primary focus of the altimeter during an emergency descent scenario. Its primary role is to inform the pilot of altitude changes to facilitate a safe and rapid descent to a designated level.