Where Flight Trackers Get Their Data, Explained
ADS-B, MLAT, satellite, ACARS, FAA SWIM, Eurocontrol — a plain-English tour of the data pipelines that power every modern flight tracker.
Why data quality is the entire game
Every flight tracker shows a plane on a map. The interesting differences are upstream — which sources they consume, how they reconcile contradictions, how fast updates ripple through.
The major sources
ADS-B (1090 MHz)
Aircraft transponders broadcast position, altitude, speed, and identity at roughly 1 Hz. Worldwide ground receiver networks (FlightAware, Flightradar24, ADSBExchange, etc.) ingest these and resell or share data via APIs.
MLAT (Multilateration)
For aircraft without ADS-B, multiple ground stations time-stamp the same Mode S transponder reply. Geometry then triangulates a position. Lower precision than ADS-B; useful for older fleets.
Satellite ADS-B (Aireon)
Iridium NEXT satellites listen to ADS-B globally, including over open ocean. This is why a 2026 tracker can show your aircraft at 35°N 40°W mid-Atlantic.
ACARS
Aircraft Communications Addressing and Reporting System: a low-bandwidth datalink between aircraft and ground (airlines and ATC). Carries OOOI events (Out, Off, On, In) used to populate gate, taxi, and arrival times.
FAA SWIM and Eurocontrol NM
Public-sector data feeds carrying flight plans, ground delay programs, airspace flow programs, and traffic management initiatives. The basis for delay-risk prediction.
Airline operational feeds
Direct (or licensed) feeds from carriers carrying schedule, gate, aircraft assignment, and in some cases bag-belt info. The reason a great tracker sometimes "knows" a gate before the airline app does — different cache.
How a modern tracker fuses it
- Position from ADS-B + satellite ADS-B.
- Schedule, gate, and status from airline + government feeds.
- Joined on flight number + tail number.
- Weather from MADIS, METAR, NEXRAD, EUMETSAT.
- Predictions from in-house models trained on years of historical OTP.
Why FlightyFlow is fast
We keep streaming connections open to multiple sources rather than polling on a timer. Cross-source reconciliation runs server-side so your iPhone gets a single, clean answer to render.
Frequently asked
Do flight trackers use FAA data?+
Yes. The FAA SWIM program publishes flight plans, traffic management data, and ground stop information that consumer flight trackers consume directly or via aggregators.
Why is ADS-B coverage weak over oceans?+
ADS-B is line-of-sight to ground receivers. Open-ocean coverage is filled in by satellite ADS-B from constellations like Aireon.
Track your next flight with FlightyFlow
Free on the App Store. Live aircraft, smart alerts, and beautiful flight pages — built for iPhone.