Time of Arrival Control (TOAC)

Time of Arrival Control (TOAC) in aviation is a method where air traffic control assigns an aircraft a specific time to arrive at a designated point, such as a runway. This allows the aircraft to self-manage its speed and navigate to reach that time. TOAC is part of a broader concept called Controlled Time of Arrival (CTA), which aims to improve fuel efficiency, predictability, and flight crew situational awareness.

Historical Development

Early Concepts: The idea of controlling arrival times was a key element in the development of air traffic control systems. Early methods involved pilots estimating their arrival times and communicating those estimates to air traffic control.

Air Traffic Control Systems: The development of radar and other technologies allowed air traffic controllers to more accurately monitor and control aircraft, leading to more precise arrival time management.

Flight Management Systems (FMS): The introduction of FMS on modern aircraft further enhanced TOAC by providing pilots with the capability to receive speed guidance to meet specific arrival time constraints.

Modern TOAC: Today, TOAC is part of a more sophisticated approach, often integrated with other advanced navigation systems like Required Time of Arrival (RTA) and Flight Interval Management (FIM).

Benefits and Challenges

Benefits: TOAC offers potential benefits like reduced fuel consumption, improved predictability, and enhanced flight crew situational awareness.

Challenges: Implementing TOAC effectively requires careful coordination between air traffic controllers, airlines, and aircraft flight crews. Challenges can include adhering to specific time constraints and managing potential variations in aircraft performance.

Summary

In summary, TOAC has evolved from early manual estimations to a sophisticated, integrated system that leverages advanced technologies to improve arrival time management and efficiency in air traffic control.