Attempting to locate an aeroplane's approximate location over Earth when seen from the ground.

16.5.11

Inclinometer/ Clinometer

An inclinometer or clinometer is an instrument for measuring angles of slope (or tilt), elevation or depression of an object with respect to gravity. It is also known as a tilt meter, tilt indicator, slope alert, slope gauge, gradient meter, gradiometer, level gauge, level meter,declinometer, and pitch & roll indicator. Clinometers measure both inclines (positive slopes, as seen by an observer looking upwards) and declines (negative slopes, as seen by an observer looking downward).

In aircraft, the "ball" in turn coordinators or turn and bank indicators is sometimes referred to as an inclinometer.