The FAA's 2014 policy change eliminated TSO certification requirements for advisory AOA displays, cutting installation costs from $6,000 to under $2,000 and finally bringing military-proven stall prevention technology within reach of every certificated aircraft.
The 2017 FAA Part 23 rewrite made AoA indicators financially viable for GA aircraft, directly addressing one of aviation's most persistent fatal accident categories.
An angle of attack (AOA) indicator measures how close your wing is to stalling directly, and the experimental fleet made it affordable for certified aircraft.