Angle of Attack Indicator

An angle of attack indicator is an instrument that provides the pilot with a direct readout of the current angle of attack relative to the wing’s aerodynamic limit. Unlike airspeed, which only indirectly indicates stall proximity, an AoA indicator shows directly how close the wing is to its critical angle — at any weight, bank angle, or configuration.

Advantages Over Airspeed Alone

Stall speed changes with weight, bank angle, g-loading, and flap setting. An AoA indicator eliminates these variables — it reads the same at the stall regardless of conditions. This makes it the most direct available measure of aerodynamic margin in slow-speed flight.

Display Types

• Indexed scale (0.0–1.0, with 1.0 at stall)
• Indexer lights (green = safe, amber = caution, red = stall)
• Tape display integrated into glass cockpit primary flight display

Safety Significance

Loss of control in-flight (LOC-I) on the base-to-final turn is the most common fatal accident scenario in general aviation. AoA awareness is a direct countermeasure. Transport Canada strongly supports wider adoption of AoA indicators in GA aircraft.

Related Terms

See also: Angle of Attack, Load Factor.