Definition
An airport certificated under FAR Part 139 that serves scheduled air carrier operations using small aircraft (those configured with 10 to 30 passenger seats) and that does not serve scheduled or unscheduled large air carrier aircraft. Class III airports must meet a defined set of FAA safety, operating, and emergency response requirements appropriate to that level of service.
Plain English
A small commercial airport that handles only scheduled airline flights flown by smaller aircraft (10 to 30 seats). It is certified by the FAA, but to a lighter set of requirements than the airports that handle full-size airliners.
Context Anchor
Seen in airport certification, airport operations, and regulatory discussions about what types of passenger flights an airport is approved to serve.
Derivation
Class comes from a Latin word meaning a group or division. Here it means a regulatory category, and III is the Roman numeral for 3, so Class III identifies the third airport certification category under Part 139.
Why Pilots Care
Tells a pilot whether the runway is long enough and the facilities adequate for the aircraft being flown, directly affecting go/no-go decisions.
Intuition Check
Do not read Class III as a quality grade or difficulty level. It is a certification category based on the type and size of passenger air carrier operations the airport may serve.
Example Sentence 1
The regional commuter line operated into a Class III airport that handled only its scheduled 19-seat turboprops.
Example Sentence 2
Before departing, the pilot confirmed the destination was a Class III airport so the aircraft performance charts would remain valid.