Squawk Codes 7500, 7600 & 7700 Explained
Squawk 7500 means hijacking, 7600 means radio failure and 7700 means a general emergency. A squawk is a four-digit code that an aircraft’s transponder transmits so air traffic control can identify it.
What a squawk is
Controllers assign a code to each flight, and the pilot enters it in the transponder. The code appears on radar next to the aircraft. Most codes are ordinary. Three are reserved for emergencies:
- 7500: unlawful interference (hijack)
- 7600: communication (radio) failure
- 7700: general emergency
Other common codes
- 2000 is used by many aircraft before they receive a code, and for aircraft entering some airspace from regions without transponder codes.
- 7000 is a common conspicuity code for aircraft flying visually in Europe; the equivalent in the US is 1200.
What to conclude
Seeing 7700 on a tracker does not by itself mean a crash. Common reasons include medical emergencies, technical problems or diversion to a nearby airport. Many 7700 events end with a normal landing. Codes can also be entered by mistake and corrected within moments.
Seeing 7600 usually means the crew lost contact with air traffic control. They follow published procedures and usually land normally.
7500 is rare. If a tracker shows it briefly, the crew may have entered it accidentally, or it may be a data error.
What to do
Do not speculate. Wait for confirmation from the airline or the authorities. Use our glossary entry for squawk for a quick definition.
General information only, not legal or safety advice. Details change; check with your airline and the relevant authority. See our editorial policy.