What function does an artificial horizon serve in aviation?

An artificial horizon, also known as an attitude indicator, plays a crucial role in aviation by showing the aircraft’s orientation relative to the earth’s horizon. It visually represents whether the wings of the aircraft are level, climbing, descending, or in a banked turn. This information is vital for pilots, especially in conditions where natural horizon references are obscured, such as in cloud cover or nighttime flying.

Understanding an aircraft's attitude is essential for maintaining control and ensuring safety during maneuvers. It allows pilots to recognize and correct any unwanted changes in orientation, helping to prevent situations such as loss of control or unintentional steep banks. The device uses a gyroscope to maintain a stable reference point that indicates pitch (up or down) and bank (left or right) deviations from level flight.

The other functions described in the other options focus on different aspects of flight operations, such as speed, altitude, fuel levels, and heading, but those responsibilities belong to other flight instruments in the cockpit, like the altimeter, airspeed indicator, fuel gauges, and heading indicator. Hence, the primary function of the artificial horizon is to indicate changes in attitude and bank.