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Heading Indicator
A gyroscopic flight instrument that provides a stable directional reference for the aircraft. Unlike a magnetic compass, the heading indicator is not affected by turning errors or magnetic dip, but must be periodically realigned with the compass.
Related Terms
- Holding PatternA predetermined maneuver that keeps aircraft within a specified airspace while awaiting further clearance from ATC. Holding patterns are racetrack-shaped and defined by a fix, inbound course, and direction of turns (standard is right turns).
- HypoxiaA condition in which the body is not getting or using enough oxygen. In flight, hypoxia can impair judgment, coordination, vision, and decision-making — sometimes with euphoria that makes the impairment hard to self-detect. Suspected hypoxia calls for supplemental oxygen and a descent as conditions allow.
- IcingIce accretion on the airframe or induction system that degrades lift, increases drag and weight, and can block pitot-static or engine induction airflow. PIREPs, AIRMETs/SIGMETs, and forecasts help pilots recognize icing risk; most light trainers lack certified ice protection, so avoidance is the primary mitigation.
- IFR (Instrument Flight Rules)A set of regulations and procedures for flying aircraft by reference to instruments only, without visual reference to the ground. IFR flight requires an Instrument Rating, an IFR-equipped aircraft, and an ATC clearance.