Squawk 7700, 7600, 7500: What the Emergency Codes Mean

Squawk 7700 means the aircraft has an emergency. Squawk 7600 means its radio has failed and the crew can’t talk to air traffic control. Squawk 7500 means the aircraft is being hijacked.

Those three numbers matter because of what they do on the ground. Code 7700 normally sets off an alarm or a special indicator at every control position in a radar facility, and 7500 triggers the special emergency indicator in all of them. One small change on a box in the cockpit, and every controller watching that patch of sky knows.

The Three Codes at a Glance

Squawk 7700: Emergency

“Squawk” is pilot talk for setting a four-digit code on the transponder, the box that answers air traffic control’s radar. 7700 is the code for trouble. The FAA’s Aeronautical Information Manual says a pilot in an emergency should squawk Code 7700 along with altitude reporting, so the controller sees both the problem and how high the airplane is. Radar facilities are set up so that 7700 normally triggers an alarm or special indicator at every control position.

Talking still matters. The same rules tell the pilot to keep squawking 7700 and get on the radio with a controller as soon as possible.

Squawk 7600: Lost Radio

When the radio goes quiet and the crew can’t reach anyone, the pilot sets the transponder to 7600. It’s a tidy fix for an awkward problem: the transponder tells controllers what the radio can’t.

Squawk 7500: Hijack

Code 7500 means the aircraft is being hijacked or forced to fly somewhere it didn’t plan to go. When controllers hear a pilot say “transponder seven five zero zero,” that’s the code being selected.

Two details matter here. Code 7500 triggers the special emergency indicator in every radar ATC facility. And air traffic control will never assign 7500 to a flight unless the pilot has told them first.

Mayday vs Pan-Pan

Squawk codes go out through the transponder. Mayday and pan-pan are spoken words, said out loud on the radio, and they sort a problem by how fast help is needed.

Mayday is the distress call. The FAA defines distress as serious or imminent danger that needs help right now. Pan-pan is the urgency call, for a safety problem that needs timely help, with a little room before it becomes immediate. The FAA calls urgency “a potential distress condition”: serious, and one step short of mayday.

Both are said three times: “Mayday, mayday, mayday” or “Pan-pan, pan-pan, pan-pan.” The ranking is written into the rules. A distress call has absolute priority over everything else on the radio, and the word mayday orders everyone else on that frequency to go quiet. An urgency call has priority over everything except distress.

If you’re wondering where the word mayday came from in the first place, I wrote about that in what mayday means and where it comes from.

What a Pilot Tells Air Traffic Control

The first call in a distress or urgency situation should begin with mayday or pan-pan, said three times. The FAA’s Aeronautical Information Manual then lists what the message should carry, preferably in this order:

• The aircraft’s identification and type
• What the problem is
• The weather
• What the pilot plans to do, and what they need
• Where the aircraft is, and its heading
• Its altitude or flight level
• Fuel remaining, in minutes
• The number of people on board

For an airline flight, the identification at the top is its radio callsign, the same “Speedbird 286” style name you’ll find on the airline callsigns list.

The last item on that list is where “souls on board” comes in. You’ll hear the phrase in films and on the radio. The FAA’s own documents, the pilot’s manual and the controller’s handbook, ask for the “number of people on board.”

FAQ

What does squawk 7700 mean? It means the aircraft has an emergency. The pilot sets 7700 on the transponder, and radar facilities are set up so the code normally triggers an alarm or special indicator at every control position.

Does a mayday call mean the plane squawks 7700? They’re two separate signals. Mayday is spoken on the radio. 7700 is a code set on the transponder. The FAA’s guidance for an emergency covers both: a pilot in an emergency should squawk 7700, and a distress call should start with mayday, said three times.

What is the difference between pan-pan and mayday? Mayday is for serious or imminent danger that needs help right away. Pan-pan is for a safety problem that needs timely help, a step short of immediate. Mayday has absolute priority and silences everyone else on the frequency. Pan-pan has priority over everything except a mayday.

What does souls on board mean? It means the number of people on the aircraft. You’ll hear the phrase in films and on the radio, while the FAA’s own documents ask pilots for the “number of people on board.”