Definition
The act of visually detecting and identifying another aircraft or object in the sky, then locking your attention onto it long enough to judge its position, distance, and relative motion.
Plain English
Spotting another aircraft, recognising what it is, and keeping your eyes on it long enough to figure out where it is and what it's doing.
Context Anchor
Used in collision avoidance when a pilot is scanning outside the airplane to find reported or unreported traffic.
Derivation
From military and radar usage, where 'acquiring a target' meant detecting and locking onto something on a screen. In civilian flying, the 'target' is simply another aircraft you've spotted, and 'acquisition' means your eyes have found and held it.
Why Pilots Care
Effective target acquisition directly reduces the risk of mid-air collisions by ensuring traffic is seen in time for evasive action.
Intuition Check
Do not read target as something to aim at, and do not read acquisition as buying something. Here, target acquisition means visually finding another aircraft and keeping track of it for safety.
Example Sentence 1
After ATC called out traffic at two o'clock, the pilot scanned the sky and confirmed target acquisition before continuing the climb.
Example Sentence 2
Once you achieve target acquisition on the converging aircraft, you can determine its flight path and decide on any needed adjustment.