7700 is the transponder code a pilot sets to tell air traffic control there is an emergency on board. The moment it's entered, the aircraft is highlighted on every controller's radar screen and gets priority handling — clear airspace, direct routing, and emergency services standing by if needed.
Almost never. A 7700 means the crew wants priority and a clear path — most end with a routine diversion and a normal landing at the nearest suitable airport. Aircraft declare emergencies far more often than the news reports them, precisely because the system is designed to make declaring one easy and consequence-free for the crew.
The word comes from the Second World War IFF system codenamed "Parrot" — controllers asked crews to "squawk" their identifying code, and the term stuck. A transponder code is still called a squawk today, and every flight gets one: 1200 (or 7000 in Europe) is the generic VFR code, and controllers assign discrete codes to identify individual flights.
Yes. Emergency squawks are broadcast in the clear over ADS-B, which is how tracking sites and apps show them. Squawk — the iOS app this site belongs to — draws emergency aircraft with pulsing rings on the map, keeps a live badge above the aircraft, and can send you a push notification the moment one appears anywhere in the world, so you can watch it play out and see where it lands.
Get Squawk on the App Store Open the live tracker
Tracking data comes from a volunteer network of ADS-B receivers. Coverage is excellent over most of North America and Europe, thinner over oceans and remote terrain, and a plane disappearing from a map usually means it flew out of receiver range or descended below the horizon — not that anything happened to it.
SQUAWK