Angle of attack displays in the cockpit – Are they fit for purpose?

Traditionally, commercial aircraft are fitted with stall warning systems and these may include audible warnings (aural cues), stick-shakers and stick-pushers (haptic cues), however few commercial aircraft are fitted with a visual display of Angle of Attack (AoA) to manage proximity to stall. Following the Air France 447 aviation accident in 2009, the Bureau d’Enquetes et d’Analyses (BEA) recommended that AoA be displayed on the flight deck to help mitigate Loss of Control In Flight (LoC-I) events and assist in recovery by increasing pilot situation awareness. In contrast, in the General Aviation (GA) sector, where LoC-I accidents also dominate fatal accident statistics, there has been a recent proliferation of commercially available AoA displays-the growth being attributed to the relaxed restrictions by the Federal Aviation Administration (FAA) with regard to the installation of AoA systems in GA aircraft. This said, there are no published design standards or certification requirements for such displays. This study, part of a larger project in Human Centred Design (HCD) of AoA presentation in relation to LoC-I, reviewed multiple presentation methods and designs in their aviation context using human factor principles to try and answer the question: are they fit for purpose?.