The Pro III is the top of the line full range AOA System comparable to instruments costing tens of thousands of dollars more. It includes a voice warning system announcing warnings of high angles of attack and landing gear position errors. The four color liquid crystal display can be dimmed and shows you angle of attack in an analog and digital format.
The donut is the target for the optimum AOA flown for all approaches and is green only when in landing configuration (Flaps). The X on the green bar is the best engine out glide AOA. The red chevrons indicate dangerously high AOAs. Nearly one-half of experimental and over one-fourth of certified aircraft fatalities are the result of stalls and spins. The killer-turn from base to final, distractions from flying the aircraft and lack of raw AOA information all contribute to these statistics. Gauging angle-of-attack is the pilot's best tool for monitoring aerodynamic performance. Best glide, maximum range, approaches and stalls are all functions of AOA, not airspeed. Optimum approach to landing speeds vary with weight, bank angle, CG and even relative humidity. With our AOA instrument, you can fly precision approaches just like Navy and airline pilots, and eliminate the need to compute performance speeds. AOA indication tells where the airspeed is going to be, unlike the airspeed indicator that tells where it was.
Your aircraft stall speed varies with gross weight, bank angle and turbulence. Your aircraft Stalling AOA (critical AOA), Approach AOA and Best Glide AOA are not affected by gross weight, bank angle or turbulence.
This is for the AOA without a heated PITOT.