Which criterion is part of the ACA establishment rules of thumb?

• A. Easily Identified from Air
• B. Ground-only identification required
• C. Exclude joint fires from planning
• D. Ignore risk assessment

Answer: (A)

When establishing an Airspace Coordination Area (ACA), a key rule of thumb is that the boundary should be easily identified from the air. This visibility allows aircraft, joint air and land teams, and observers to recognize the limits quickly, reducing misidentification and enabling prompt deconfliction and coordinated fires. Being easily seen from air supports rapid planning and execution, which is essential in fast-paced joint environments.

Why the other ideas don’t fit: a ground-only identification requirement would slow things down and rely on information that air assets might not have readily, defeating the purpose of an air-identified boundary. Excluding joint fires from planning contradicts the fundamental purpose of an ACA, which is to coordinate and deconflict fires across agencies and services. Ignoring risk assessment would undermine safety and effectiveness, since risk assessments are integral to any fire planning and airspace management.