During which phase must the aircraft be tracked and a fire control solution determined?

The engagement phase is crucial in missile defense systems and similar operations, as it involves active measures to intercept and neutralize a threat. During this phase, tracking the aircraft is imperative because it allows for real-time data collection on its trajectory, speed, and other characteristics necessary for accurate targeting. Additionally, determining a fire control solution is essential to effectively guide interceptor missiles to the threat. This solution encompasses various calculations and assessments to ensure that a successful interception occurs.

In contrast, the detection phase primarily focuses on identifying that a threat exists, while the assessment phase is concerned with evaluating the effectiveness post-engagement. The recovery phase deals with returning to normal operations following an incident or engagement. Therefore, it is in the engagement phase where both tracking and fire control decisions are critically required to engage the target effectively.