What the terms mean
Air traffic language written for passengers rather than pilots or controllers.
- Ground stop(GS)
- Flights heading to one airport are held on the ground where they are, until the airport can accept more arrivals. If your flight has not left yet, it may wait at the gate.
- Ground delay program(GDP)
- Flights to a busy airport are each given a controlled departure time so arrivals arrive more slowly. This usually shows up as a departure delay of a set number of minutes.
- Arrival or departure delay
- Air traffic is moving, but slower than normal at that airport. The published average is a typical delay, not a promise about your flight.
- SWAP(Severe Weather Avoidance Plan)
- A plan for routing airplanes around thunderstorms. Flights are still going, but they may take longer paths.
- CDR(Coded Departure Route)
- An alternative route prepared in advance so flights can be moved quickly around a problem area.
- Escape route
- A route used to steer departing traffic around crowded or stormy airspace.
- Miles-in-trail(MIT)
- Airplanes are being spaced farther apart than usual. Fewer aircraft fit through the same airspace, so delays can build.
- Staffing trigger
- Fewer controllers are available than planned, which can lower how much traffic an area can handle.
- SIGMET(Significant Meteorological Information)
- A warning to pilots about hazardous weather such as thunderstorms, severe turbulence or icing over a defined area.
- AIRMET / G-AIRMET
- A forecast of less extreme but still notable conditions such as moderate turbulence, low clouds or icing. G-AIRMET is the graphical version.
- PIREP(Pilot report)
- A pilot describing what they actually experienced in flight, such as light or moderate turbulence at a certain altitude.
- Convective forecast (TCF)(Traffic Flow Management Convective Forecast)
- A forecast of where thunderstorms are expected to affect air traffic later today, with how much of the area they may cover.
- TSTMS / WX
- Shorthand for thunderstorms and weather in FAA advisories.
- OTS(Out of service)
- A runway, taxiway or piece of equipment is temporarily unavailable.
- Flight category (VFR, MVFR, IFR, LIFR)
- How clear the sky and visibility are at an airport. VFR is clear, MVFR is marginal, IFR and LIFR mean low clouds or poor visibility, which usually slows arrivals.
Airspace region codes
FAA advisories name air traffic regions by code. Here is what each one covers.
- ZAB — Albuquerque area airspace
- ZAN — Alaska airspace
- ZAU — Chicago area airspace
- ZBW — New England airspace
- ZDC — Washington, D.C. area airspace
- ZDV — Denver area airspace
- ZFW — Fort Worth area airspace
- ZHU — Houston area airspace
- ZID — Indianapolis area airspace
- ZJX — Jacksonville area airspace
- ZKC — Kansas City area airspace
- ZLA — Los Angeles area airspace
- ZLC — Salt Lake City area airspace
- ZMA — Miami and South Florida airspace
- ZME — Memphis area airspace
- ZMP — Minneapolis area airspace
- ZNY — New York area airspace
- ZOA — Northern California airspace
- ZOB — Cleveland area airspace
- ZSE — Seattle area airspace
- ZTL — Atlanta area airspace
- ZHN — Honolulu area airspace
- PCT — Washington, D.C. approach airspace