Emergency Squawk Alerts

Summary: How the map automatically highlights aircraft squawking an emergency code.

The map automatically watches for aircraft transmitting one of the three international emergency squawk codes:

• 7500 — unlawful interference (hijack)
• 7600 — radio failure
• 7700 — general emergency

This is switched on by default — no setup needed. When an aircraft near the UK squawks one of these codes, the map automatically zooms to it and opens its info panel, and (if audio alerts are enabled) plays a distinct alert tone.

The map also shows traffic over near Europe. An emergency there is still marked in the aircraft’s info panel and shown in red in the aircraft table, but it doesn’t zoom the map or sound the alert.

Which frequency to listen on

A crew declaring an emergency does it on the frequency they are already working, and stays there: the controller who already has the aircraft keeps it, clears other traffic and co-ordinates the help. Guard, 121.5 MHz, is a backup for when contact on that frequency is lost, when another aircraft relays, or when the crew are unsure which frequency to use. The aircraft’s Listen on block follows the same rule: it headlines the working frequency, marked emergency declared here, with Guard (or UHF Guard, 243.0, for a military aircraft) as the first alternative. See Listen On: How the Map Predicts a Frequency.