Which instruments are involved in monitoring the aircraft's altitude?

Monitoring an aircraft's altitude is crucial for ensuring a safe flight, and the instruments that specifically serve this purpose include the altimeter, vertical speed indicator (VSI), and radar altimeter.

The altimeter is the primary instrument used to measure the altitude of the aircraft above sea level by interpreting changes in atmospheric pressure. As the aircraft ascends or descends, the pressure changes, and the altimeter reflects these changes as a change in altitude.

The vertical speed indicator (VSI) complements the altimeter by indicating the rate of climb or descent in feet per minute. This helps pilots understand how quickly they are changing altitude, which is essential for maintaining stable flight and adherence to altitude restrictions.

The radar altimeter, on the other hand, measures the actual altitude above the terrain directly below the aircraft, using radio waves. This is particularly useful during low-altitude operations, such as approaches and landings, where precise altitude information is critical.

In contrast, while other options may include instruments related to flight operations, they do not specifically address altitude monitoring. Instruments like the compass and airspeed indicator are involved in navigation and airspeed management, while gyroscopes and inclinometers relate more to orientation and stabilization rather than direct altitude measurement. The bar