Which instrument measures the rate of climb or descent in feet per minute?

The instrument that measures the rate of climb or descent in feet per minute is the vertical speed indicator. This device provides critical information to pilots by displaying how quickly the aircraft is ascending or descending, allowing for necessary adjustments to maintain the desired altitude or to execute a safe landing.

When an aircraft is climbing or descending, this indicator uses a diaphragm and a static pressure system to reflect changes in altitude over time. A positive reading indicates a climb, while a negative reading indicates a descent. This information is vital for pilots to make informed decisions during flight, especially during takeoff, cruising, and landing phases where maintaining a specific altitude is crucial for safety and efficiency.

Other instruments such as the altimeter provide altitude readings, while the airspeed indicator measures how fast the aircraft is moving through the air. The artificial horizon, also known as an attitude indicator, shows the orientation of the aircraft in relation to the horizon but does not convey rate of climb or descent. Each of these tools serves different purposes within the cockpit, emphasizing the specialized function of the vertical speed indicator in monitoring vertical motion.