Plain English Meaning

A free phone number pilots call to talk to a Flight Service specialist before a flight to get weather information and file a flight plan.

Full Definition

The toll-free telephone number used in the United States to reach Flight Service for preflight weather briefings, flight plan filing, and other flight planning services provided by Flight Service Stations (FSS).

Context Anchor

Seen in preflight planning discussions and in references to Flight Service Station services.

Derivation

The 'WX' is the standard aviation and meteorology shorthand for 'weather.' The number spells 'weather brief' on a phone keypad to make it easy to remember.