- The data exists, and we asked for permission.
- There is an open database that turns a flight number into an origin and a destination. Its licence states that the route data may not be copied, published, or incorporated into other databases without its author's explicit permission. So we did not use it — and on 4 September 2026 we asked in public how that permission is requested. If the answer is no, we still will not use it.
- The other source forbids commercial use.
- OpenSky has history, and its licence is non-commercial and forbids advertising. If this ever has to pay for itself, starting on that foundation would mean building something we would have to tear down.
- The long way is tested, and it works.
- adsb.lol publishes its full history under the Open Database License: about 3.9 GB a day with the traces of every aircraft on the planet. We downloaded half a day and distilled it: 80,435 flights, with registration, model, take-off and landing. It came to 219 bytes per flight — around 13 GB a year, which fits on an ordinary server.
The airlines and aircraft that came out — Delta, Southwest, Ryanair; Boeing 737, Cessna 172, Airbus A320 — match known reality, and nobody told the program: it worked them out by looking. With that, where did it come from gets answered with our own data and nobody's permission. - And why it is not here yet.
- Because only 37% of those flights have both an origin and a destination: where there are no volunteers with antennas there is no coverage, and the aircraft simply appears already airborne. And there is a pattern we have not explained — many flights leave from and arrive at the same airport. That may be real (a flight school does exactly that all day) or it may be a flaw of ours. Until we know which, it does not get published.