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Airspace Coordination Area (ACA)


An Airspace Coordination Area (ACA) is a three-dimensional block of airspace established by military authorities to coordinate and regulate the usage of airspace during combat or training operations. It is primarily used to facilitate the safe passage and separation of friendly aircraft, while minimizing the risk of incidents such as friendly fire. The ACA ensures effective cooperation and communication between various components of air, land, and sea forces to maintain situational awareness and operational efficiency.

Key Takeaways

  1. An Airspace Coordination Area (ACA) is a three-dimensional block of airspace that is temporarily established during military operations to separate different types of aircraft and ensure safety between friendly forces.
  2. ACAs are set up by coordinating with all involved parties, including air traffic control, to allow for specific types of aircraft to operate within that airspace without interfering with each other, thus reducing the potential for friendly fire incidents and collisions.
  3. Operational planning and fast communication between all participating units are essential for the effective management of ACAs, enabling seamless coordination and execution during air combat, close air support, and surveillance missions.


The military operations term, Airspace Coordination Area (ACA), is important because it plays a crucial role in enabling the safe and efficient execution of joint and combined air operations.

An ACA is a three-dimensional block of airspace in a specific area, established by the appropriate commander to coordinate and deconflict the movements of multiple air assets, such as aircraft, unmanned aerial systems, and fires (artillery, missiles). By establishing an ACA, military commanders mitigate the risk of mid-air collisions and fratricide, while enhancing the effectiveness of their operations.

Furthermore, it provides a clear communication framework that ensures all units are aware of designated routes and altitudes, promoting operational agility and seamless coordination among multiple forces.


The primary purpose of an Airspace Coordination Area (ACA) is to provide a designated section of airspace, strategically determined, to ensure that efficient and safe coordination occurs between the various military units participating in air operations. This three-dimensional airspace, usually allocated over a specific geographic zone, allows forces to conduct combined arms operations simultaneously, leading to the establishment of air superiority and the fulfillment of mission objectives.

By segregating the airspace for various activities, such as combat air support, reconnaissance, and aerial refueling, an ACA ensures minimal risk of collisions, fratricide, or any unintended encounters with friendly aircraft. Additionally, it facilitates proper information sharing and command and control among the essential units, ultimately increasing synergy among the military components involved in the operation.

ACAs serve as a vital mechanism for managing complex, time-sensitive operations in both joint and coalition environments involving multiple aircraft and support assets. It is imperative for the efficient execution of combined air-ground operations that every unit be well-versed in the ACA structure’s rules and procedures.

Utilizing an ACA permits forces to function harmoniously while optimizing air and ground assets, and as a result, maximize lethality against enemy targets while minimizing collateral damage. By enabling the safe execution of aviation operations, Airspace Coordination Areas significantly contribute to the military’s capacity to perform effectively and achieve mission success.

Examples of Airspace Coordination Area (ACA)

Operation Desert Storm (1991) – During the Gulf War, the airspace over Iraq and Kuwait was heavily managed to ensure effective coordination between the multi-national air forces. Airspace Coordination Areas (ACAs) were established to allow various air missions like close air support, interdiction, and air superiority to be executed safely and effectively while preventing mid-air collisions and miscommunications. This large-scale operation showcased the importance of properly managing and organizing airspace during military operations.

Operation Allied Force (1999) – In the conflict over Kosovo, the North Atlantic Treaty Organization (NATO) conducted an air campaign against the then Federal Republic of Yugoslavia. To ensure optimal coordination among NATO allies, ACAs were implemented to streamline different air missions conducted by multiple countries including the United States and the United Kingdom. ACAs were essential in avoiding operational conflicts and confusion within the congested airspace during this complex military operation.

The No-Fly Zone over Libya (2011) – The United Nations Security Council Resolution 1973 authorized a no-fly zone over Libya during the Libyan Civil War in

This no-fly zone served as an Airspace Coordination Area, allowing NATO forces to maintain air superiority over the Libyan airspace and perform various missions such as air surveillance, combat air patrol, and humanitarian aid support. This ACA helped coalition forces create a safe and organized operational space for their air assets while helping to protect the civilian population from potential attacks from the air.

Airspace Coordination Area (ACA) FAQ

What is an Airspace Coordination Area (ACA)?

An Airspace Coordination Area (ACA) is a three-dimensional block of airspace in a defined area, established by a higher authority to provide separation between air operations in support of ground forces. It is an essential component of deconfliction between aircraft and ground elements during military operations.

What is the purpose of an ACA?

The main purpose of an ACA is to provide a coordinated airspace area for aircraft operations, ensuring separation between friendly air assets and minimizing the risk of mid-air collisions or unintentional engagements. The ACA also facilitates better communication and collaboration between air and ground elements during operations.

How is an ACA established?

An ACA is typically established by a higher authority, such as the Joint Force Air Component Commander (JFACC), based on the operational needs of the mission and the existing airspace structure. The dimensions, altitude range, and time frame of the ACA are determined in coordination with other airspace users and controlling agencies, ensuring the safe and effective use of the airspace during military operations.

What are the different types of ACA?

There are two main types of ACA: Formal and Informal. A Formal ACA is established with specific dimensions, altitudes, and time frames, and is designated in the airspace control plan. An Informal ACA is a temporary measure, usually established on a case-by-case basis during operations, to accommodate specific mission requirements and ensure separation between aircraft and ground forces.

How do aircraft operating within an ACA coordinate with ground forces?

Aircraft operating within an ACA communicate with ground forces through designated communication channels, such as radio frequencies and tactical data links, in order to maintain continuous situational awareness and coordinate maneuvering as needed. Airborne assets are often supported by ground-based airspace control elements, such as the Airspace Control Authority (ACA), who help facilitate communication and coordination between the aircraft and ground forces.

Related Military Operation Terms

  • Air Traffic Control (ATC)
  • Terminal Control Area (TCA)
  • Temporary Flight Restriction (TFR)
  • Controlled Airspace
  • Vertical and Lateral Boundaries

Sources for More Information