Found a bug, have a feature idea, or a question about the data or methodology? Messages go directly to Jeff — I read everything and reply to every genuine message.
Personal and educational use is always free — no credit required, though a mention is appreciated. For commercial use, embedding in a product, or institutional deployment, please reach out via the form and describe your use case. I'm happy to discuss options.
Send the ICAO code, IATA code, full name, and coordinates (decimal degrees) via the contact form and I'll add or correct it. The database covers 12,174 airports — omissions are usually smaller regional or private fields.
No — Great Circle Pro is for educational and analytical purposes only. Wind and fuel figures are estimates. Do not substitute for certified dispatch software, approved performance calculations, or NOTAMs. See the disclaimer on every page.
The most useful reports include: (1) your browser and OS, (2) the airport codes or route used, (3) what you expected vs. what happened, and (4) a screenshot if possible. Select Bug Report in the subject dropdown.
Feature suggestions are very welcome. The most useful ones explain the underlying problem or use case rather than just the solution — that context helps enormously when evaluating what to build next.
Wind data comes from NOAA GFS 250 hPa, updated every 6 hours — the same source used by many professional weather services. Fuel figures are cruise-phase estimates based on published consumption rates, scaled by load factor. They are reasonable planning approximations, not certified performance data.