Definition
The pilot's ongoing responsibility to see other aircraft, terrain, and obstacles in time to take action that prevents a collision. In visual conditions, this is accomplished primarily through systematic outside scanning, supplemented by traffic advisories, onboard traffic displays, and standard right-of-way procedures.
Plain English
Actively looking outside the cockpit and using available tools to spot other aircraft or obstacles early enough to stay clear of them.
Context Anchor
You encounter this during preflight planning, taxi, takeoff, climb, cruise, descent, landing, and any time you are scanning outside the airplane for traffic or hazards.
Derivation
Collision comes from a Latin word meaning “to strike together.” Avoidance means keeping away from something. Together, the phrase points to the goal: keep aircraft and other hazards from ever reaching the point where they strike each other.
Why Pilots Care
Mid-air collisions are almost always fatal; collision avoidance is a pilot's direct responsibility and the last line of defense after air traffic control and technology.
Intuition Check
Collision avoidance does not mean waiting until something is close and then reacting. In flying, it means staying alert early enough to prevent the close call from developing.
Example Sentence 1
The instructor reminded the student that collision avoidance starts with eyes outside the cockpit, not on the instruments.
Example Sentence 2
In the traffic pattern the instructor stressed that collision avoidance depends on seeing other aircraft early and yielding when required.