In a turn, what does the inclinometer indicate?

• A. The aircraft's pitch attitude
• B. The bank angle
• C. The relationship between gravity and centrifugal force in a turn
• D. Lateral acceleration

Answer: (C)

In a turn the aircraft experiences two main forces: gravity pulling downward and a centrifugal tendency pushing outward. The inclinometer measures the tilt of the apparent gravity—the vector sum of gravity and centrifugal force as felt in the airplane. It shows how these forces balance in the turn, which tells you about the coordination of the turn. If the turn is coordinated, the resultant points straight down in the aircraft’s frame and the indicator is centered; if there’s slip or skid, the indicator tilts toward the outside of the turn. This instrument isn’t a direct readout of pitch, bank angle, or lateral acceleration, but a readout of how gravity and centrifugal force relate to one another during the turn.