Definition
An airport that meets the operational requirements for a particular flight, including adequate runway length, suitable approach and landing aids, acceptable weather minimums, and services appropriate to the aircraft type and the nature of the operation. Used in flight planning to identify airports that may be filed as a destination or alternate.
Plain English
An airport that is good enough — in size, equipment, weather, and services — to safely handle the planned flight or to serve as a backup if the destination becomes unusable.
Context Anchor
Seen in flight planning, airline dispatch, alternate airport selection, and diversion planning.
Derivation
Suitable comes from the idea of something being fitted or appropriate for a purpose. In aviation, that is the key point: the airport must fit the airplane, the weather, and the operation, not merely exist on the map.
Why Pilots Care
Choosing a suitable airport keeps the flight legal and safe; an unsuitable one can force a violation or unsafe landing.
Intuition Check
Do not read suitable as simply meaning convenient or nearby. In this context, it means the airport meets the practical and required conditions for that airplane to land there safely.
Example Sentence 1
Before departure, the dispatcher confirmed that the planned alternate was a suitable airport for the forecast weather and the aircraft's landing performance.
Example Sentence 2
After the engine issue they diverted to the nearest suitable airport that met the ceiling and visibility minimums.