How Flight Tracking Actually Works

The four big data sources

A modern flight tracker is a fusion engine. It combines several independent sources to show you a single answer.

1. ADS-B (Automatic Dependent Surveillance–Broadcast)

Every commercial aircraft constantly broadcasts its position, altitude, speed, and identity over a 1090 MHz radio. A worldwide network of ground receivers — many of them volunteer-operated — listens to those broadcasts. The data is then aggregated into the live map you see in your app.

ADS-B coverage is excellent over land, weaker over remote ocean.

2. MLAT (Multilateration)

Older aircraft that don't transmit ADS-B can still be located by measuring tiny differences in arrival time of their transponder signals at multiple ground stations. The geometry gives you a position. It's less precise than ADS-B but useful for fleet completeness.

3. Satellite ADS-B

Constellations like Aireon listen to ADS-B from low Earth orbit, filling in the ocean gaps. This is why you can now track a flight from New York to London for the entire crossing, not just the coastlines.

4. ACARS and airline operational feeds

Aircraft talk to their airlines via ACARS (Aircraft Communications Addressing and Reporting System). Airlines also publish operational feeds — gate, baggage, scheduled times — that consumer apps subscribe to. This is where the gate, status, and delay data come from, separate from the position data.

How a flight tracker fuses it together

A good app:

1. Pulls position from ADS-B (and satellite ADS-B over oceans).
2. Pulls schedule, gate, and status from airline feeds and FAA/Eurocontrol systems.
3. Joins the two by flight number plus aircraft registration.
4. Layers weather radar and ATC program info on top.
5. Runs models to predict delay risk and turn time.

Latency from radio to your screen is typically under 5 seconds in well-covered airspace.

Why you sometimes see no plane on the map

A few reasons:

• The aircraft may not yet be airborne.
• ADS-B coverage is weak in the area (deep ocean, polar route).
• A military aircraft is filtered out.
• Some private operators block their tail number from public display via the FAA's PIA / LADD programs.

Why FlightyFlow is fast

FlightyFlow keeps a hot connection open to a streaming pipeline rather than polling on a timer. That's why position updates feel smooth and statuses change the moment the airline does.