Definition
The segment of an instrument flight that begins as the aircraft transitions from en route cruise toward the destination airport and continues through the instrument approach until landing or a missed approach. During this phase, navigation equipment such as LNAV/VNAV systems must meet tighter accuracy and integrity requirements than during en route flight, because the aircraft is descending closer to terrain and obstacles and is being guided along increasingly precise lateral and vertical paths.
Plain English
The part of the flight where the aircraft leaves cruise, descends toward the destination airport, and flies the published approach down to the runway. The rules for navigation accuracy get stricter here because the aircraft is getting closer to the ground.
Context Anchor
Seen in instrument procedure and navigation-equipment discussions, especially when describing how equipment behaves as the aircraft gets closer to the airport and runway.
Derivation
Arrival comes from an old word meaning to come to shore or reach a destination. Approach comes from a word meaning to come nearer. Phase means a stage or step in a process. Together, the term points to the stage where the flight has reached the destination area and is moving closer to the runway.
Why Pilots Care
Correctly identifying this phase ensures navigation modes are armed at the right time and descent profiles are flown safely.
Intuition Check
Do not read “arrival/approach phase” as only the instant the aircraft arrives, or only the last few seconds before landing. Here it means a defined stage of instrument flight that includes getting into position for the approach and then flying the approach path.
Example Sentence 1
Once cleared for the RNAV approach, the crew confirmed the GPS had transitioned to the tighter accuracy mode used in the arrival/approach phase.
Example Sentence 2
Briefing the arrival/approach phase before descent helps the crew anticipate when to switch from en route to approach navigation.