The FAA Recommends AOA Indicators For All Aircraft
By Justin Foster
In late December, the Federal Aviation Administration (FAA) released a special airworthiness information bulletin (SAIB) focused on the future installation of angle of attack (AOA) indicators and systems for aircraft. The bulletin, which was released on December 26 of last year, was titled Stall Warning System: Angle of Attack Alerting Systems. It provides a simple suggestion to all general aviation aircraft owners and operators to ensure their aircraft is fitted with an AOA system of some sort, which provides many benefits to the aircraft owners and operators. The FAA mentioned in the bulletin, which is designated 2024-07, that these benefits may include the possible reduction in risk of loss-of-control (LOC) incidents or accidents.
Special bulletin for an AOA recommendation
On Thursday, December 26th, 2024, the Federal Aviation Administration (FAA) released a special airworthiness information bulletin (SAIB) titled Stall Warning System: Angle of Attack Alerting Systems. Specifically, this SAIB provides information to help general aviation aircraft owners and operators understand the importance and safety benefits of AOA alerting systems. The SAIB is also specific to aircraft that are type certified under the Part 23 regulations, which is the category for normal airplanes.
- Flight crew’s failure to monitor airspeed in relation to the rising position of the low-speed cue
- Flight crew’s failure to adhere to sterile cockpit procedures
- Captain’s failure to effectively manage the flight
- Colgan Air’s inadequate procedures for airspeed management during approach in icing conditions
Overall, the NTSB came to several conclusions regarding the incident. Specifically, the NTSB recommended that the FAA begin to require the installation of low airspeed alerting systems on all aircraft. This includes a system that provides pilots with redundant warnings of potentially hazardous low-speed conditions. Because of this, under SAIB 2024-07, the FAA officially recommends that all owners and operators of all part 23 aircraft, or aircraft that are operating under Part 121, 135, or 91, install and calibrate critical AOA systems. The FAA also recommends that all owners and operators receive training on how to use the AOA indicators in their avionics systems.
What does an AOA indicator or AOA system do?
In terms of general aviation aircraft, an AOA system measures and displays the angle at which an aircraft’s wing meets the oncoming airflow. Essentially, this indicates how much lift is being generated by the aircraft. As the lift of an aircraft decreases, the potential for an aerodynamic stall increases. So, primarily, an AOA system warns pilots when they are approaching an aerodynamic stall by alerting them to a critical angle of attack. An AOA system helps pilots to maintain safe flight conditions, as an AOA system provides a more precise stall warning than simply just using airspeed measurements.
The AOA system is typically displayed on the cockpit’s instrument panel. It also typically uses lights or a gauge to provide visual warnings or indicators to the flight crew. Some AOA systems also provide audio warnings when approaching a critical angle of attack, which may improve the system’s reliability, due to the built-in redundant systems.
