In December 2024, the Federal Aviation Administration (FAA) issued a Special Airworthiness Information Bulletin (SAIB) recommending the installation of Angle of Attack (AOA) indicators in general aviation aircraft. The bulletin, titled Stall Warning System: Angle of Attack Alerting Systems, highlights the importance of these systems in enhancing safety and reducing the risk of loss-of-control (LOC) incidents.
Understanding the FAA’s AOA Recommendation
Released on December 26, 2024, the FAA’s bulletin (designated SAIB 2024-07) encourages owners and operators of general aviation aircraft certified under Part 23 regulations to install AOA systems. These systems provide critical safety benefits, especially in preventing aerodynamic stalls, which are among the leading causes of aviation accidents.
The bulletin emphasizes the role of AOA systems in alerting pilots to critical conditions, helping them maintain safe flight parameters. It also highlights the importance of training flight crews on the proper use of AOA indicators integrated into modern avionics systems.
Lessons from the Colgan Air Accident
The FAA’s recommendation stems partly from insights gained from the tragic crash of Colgan Air flight 3407 on February 12, 2009. This Bombardier DHC-8-400 aircraft crash in Clarence Center, New York, resulted in the loss of 50 lives, including four crew members, 45 passengers, and one person on the ground.
The National Transportation Safety Board (NTSB) identified several factors contributing to the crash, including:
- The captain’s inappropriate response to the activation of the stick shaker, leading to an unrecoverable aerodynamic stall.
- The flight crew’s failure to monitor airspeed in relation to the low-speed cue.
- Non-adherence to sterile cockpit procedures.
- Ineffective flight management by the captain.
- Colgan Air’s inadequate airspeed management protocols during approaches in icing conditions.
Based on these findings, the NTSB recommended that the FAA require low-airspeed alerting systems in aircraft. The FAA’s SAIB 2024-07 incorporates these recommendations by advocating for AOA systems to provide redundant and precise warnings of hazardous low-speed conditions.
What Does an AOA System Do?
Angle of Attack (AOA) systems measure and display the angle at which an aircraft’s wings meet the oncoming airflow, known as the angle of attack. This measurement indicates the lift being generated by the wings, and a critical angle of attack signals the risk of an aerodynamic stall.
Key Functions of AOA Systems:
- Stall Warning: Alerts pilots when the aircraft approaches a critical angle of attack, reducing the risk of stalls.
- Improved Accuracy: Offers more precise warnings than traditional airspeed indicators.
- Visual and Audio Alerts: Displays visual warnings via cockpit instruments and, in some systems, provides audio alerts for added redundancy.
- Safe Flight Management: Helps pilots maintain optimal flight conditions, especially during takeoff, landing, or maneuvers in adverse weather.
These systems are typically installed on the cockpit’s instrument panel and use gauges, lights, or digital displays to communicate real-time data. Advanced systems may also provide auditory cues for enhanced situational awareness.
The FAA’s recommendation to install AOA indicators is a proactive step towards improving flight safety in general aviation.
By providing accurate and timely warnings of potentially hazardous conditions, these systems can significantly reduce the risk of loss-of-control incidents. For aircraft owners and operators, investing in AOA systems and training represents a commitment to safety and operational excellence.
FAQ
1. What is an AOA system, and why is it important?
An AOA system measures the angle at which an aircraft’s wings meet the airflow, indicating lift. It warns pilots when the aircraft approaches a critical angle of attack, reducing the risk of aerodynamic stalls.
2. Why did the FAA release this bulletin?
The FAA issued the bulletin to encourage the installation of AOA systems, highlighting their role in preventing loss-of-control incidents, such as the one involving Colgan Air flight 3407 in 2009.
3. What aircraft does this recommendation apply to?
The recommendation applies to general aviation aircraft certified under Part 23 regulations, as well as aircraft operating under Part 121, 135, or 91 rules.
4. Are pilots required to install AOA systems?
As of now, the FAA’s SAIB 2024-07 is a recommendation, not a mandate. However, it strongly encourages aircraft owners and operators to install these systems for enhanced safety.
5. What kind of training is needed for AOA systems?
The FAA recommends that flight crews undergo training to understand and effectively use AOA indicators, ensuring they can interpret warnings and respond appropriately.