Definition

An Attitude Direction Indicator (ADI) is a flight instrument that combines a traditional attitude indicator with limited navigational information. An ADI can be part of an Electronic Flight Instrument System (EFIS) display or a mechanical instrument.

Description

An ADI combines flight director command bars with a standard gyroscopic attitude indicator, which displays aircraft pitch and roll. Some models also display Instrument Landing System (ILS) guidance in the form of localizer and glideslope needles. This combination allows a pilot to monitor an aircraft's orientation and position on a single instrument while flying an approach in instrument meteorological conditions (IMC).