Definition
In aeronautical decision-making instruction, the three phases refers to the three stages a pilot moves through when handling a situation in flight: perception (recognizing that a change or problem exists), processing (evaluating what it means and deciding what to do), and performance (carrying out the chosen action and monitoring the result).
Plain English
When something comes up in flight, a pilot goes through three steps: notice it, think it through, then act on it and check that the action worked.
Context Anchor
Seen in aviation decision-making training, especially when an instructor is teaching a pilot how to handle changing conditions or unexpected problems.
Derivation
Phase comes from a Greek word meaning an appearance or stage. That helps here because each phase is one stage in a process, not a separate subject by itself.
Why Pilots Care
Gives instructors a repeatable framework so students develop consistent, safe habits instead of reacting without a plan.
Intuition Check
Do not read three phases here as three parts of a flight, such as takeoff, cruise, and landing. In this context, it means three steps in making a safe decision.
Example Sentence 1
The instructor walked the student through the three phases after the engine roughness scenario, asking how she perceived the change, processed her options, and performed the diversion.
Example Sentence 2
Applying the three phases helped the pilot stay calm and choose the best runway during a crosswind landing.