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Squawk code · special

Squawk 2000: Entering SSR airspace without a code

Squawk 2000 is the ICAO code for an aircraft entering secondary radar coverage without having been assigned a code.

Squawk 2000 is what an aircraft squawks when it enters radar airspace without an assigned code. In practice you see it on flights arriving from oceanic airspace or from regions without secondary radar, until a controller assigns a discrete code.

What 2000 means

ICAO procedures (Doc 8168 and regional supplements) say that when no code has been assigned, IFR aircraft entering an area where secondary surveillance radar (SSR) is used should set 2000. Over the middle of the Atlantic or Pacific there is no SSR, so oceanic flights historically had no need of a discrete code, and in some regions they squawk 2000 as they approach land. Once a radar controller identifies the flight, they assign a unique code.

In the US, 2000 is also used in some operations as a non-discrete code, and in parts of the world it is the default setting of a new transponder.

How 2000 appears on heywhatsflying

You might see 2000 on an airliner coming in from Europe or Asia near the edge of our US box, or on aircraft operating far offshore in the Gulf of Mexico. It is usually short-lived. Because our snapshot covers 24 to 50 degrees north and 125 to 66 degrees west, flights arriving from overseas pass through 2000 at the edges. Check their callsign on the airlines and operators guide.

Good to know

  • Today many oceanic flights keep a discrete code assigned before departure and use ADS-B and satellite datalink for position reports, so 2000 is less common than it once was.
  • A 2000 code is not an emergency and says nothing about the state of the flight.

Related codes: 1200 (US VFR), 7000 (European VFR) and 1000. See the full squawk code index and how to read flight data.

Questions

What does squawk 2000 mean?

It is the ICAO code for an aircraft entering secondary radar coverage without an assigned code, typically after crossing oceanic airspace. A controller then assigns a discrete code.

Is squawk 2000 an emergency?

No. It is a routine, non-discrete code that simply means no specific code has been assigned yet.