Why a flight might travel farther
A great circle is the shortest surface path between two points on a spherical Earth. It is a useful baseline for comparing airports. It does not describe every route an aircraft can use. Geographic exclusions can force a route away from that baseline, sometimes adding substantial distance.
Airpath lets you explore that difference. Enter city names or airport codes, choose regions to avoid, and compare a feasible modeled route with its great-circle distance. The purpose is to make geographic detours visible and measurable. The result is an estimate for exploration, not an airline flight plan.
Three ways to explore
| MODE | EXAMPLE | WHAT IT DOES |
|---|---|---|
| Paths | LHR-HND | Maps a route from London Heathrow to Tokyo Haneda. |
| Ranges | 3000nm@LHR | Estimates the area reachable within a distance budget. |
| Distances | JFK-LHR-CDG | Compares direct and exclusion-aware distances for each leg. |
Use hyphens to add stops and commas to compare separate itineraries. For example, SFO-NRT-SIN,SFO-HKG-SIN compares two paths from San Francisco to Singapore, via different connecting airports. Slash-separated alternatives such as JFK/EWR-LHR/CDG expand into separate routes. Airport inputs accept IATA and available ICAO codes. City names use city-centre coordinates from GeoNames; they do not substitute a nearby airport. Type London to Tokyo, combine a city and an airport such as Paris to JFK, or try 3000nm@London. Select a suggestion when a name is ambiguous, or qualify it as Portland [Oregon, US]. The bundled gazetteer covers cities over 15,000 people plus capitals. Smaller places may need a nearby airport code. Use “to” or quoted names for cities containing hyphens.
Choose what to route around
Search for a country or click it on the map to exclude its outline. Conflict-advisory presets provide editable proxies for selected published EASA advisories. The list is a snapshot checked on 27 October 2026, not a live feed of airspace closures. Some advisories cover only specific operators, provinces, altitudes, or FIRs; Airpath uses broader country proxies rather than reproducing those detailed rules.
Terrain options include schematic Tibetan Plateau and Himalayan outlines. They are optional avoidance preferences, not claims that those regions are universally inaccessible. You can also draw a custom area or import a Polygon or MultiPolygon GeoJSON file. The boundary buffer adds a chosen clearance around the modeled edges. Country outlines represent land boundaries and do not reproduce authoritative territorial-sea or FIR limits.
Washington, DC Flight Restricted Zone
Under “Terrain & custom areas,” select Washington, DC — Flight Restricted Zone (FRZ) to route around the inner, irregular 13–15 nautical mile boundary. The geometry comes from FAA Aeronautical Information Services and includes the Freeway Airport cutout. Use “View” to inspect the boundary without selecting it as an exclusion. This is a snapshot checked 27 October 2026, from the 3 September–29 October 2026 cycle (0901 UTC).
The published FRZ extends from the surface to below FL180. Approved operations and waivers exist, including scheduled commercial flights at Reagan National. Selecting the preset makes its full horizontal footprint an avoidance preference at all altitudes, plus the chosen boundary buffer. The app does not evaluate flight permissions or altitude. The surrounding 30 nautical mile Special Flight Rules Area is not treated as a blanket no-fly zone.
China airspace is paused
The previous China layer and its source data have been archived while a more complete, authoritative dataset is sought. It is not displayed or used in distance estimates and exports. China selections in older saved or shared plans remain inactive.
Explore flight Wi-Fi
The Flight Wi-Fi page pairs a route with an airline and, when known, an aircraft or installed system. It identifies documented providers and maps Starlink aviation approval countries plus named geographic conditions from Delta and Qantas. Approval is different from signal coverage; unknown areas remain unverified. Current exact footprints for the documented legacy Panasonic, Intelsat and GX systems were not verified. The page does not look up an individual flight, assigned aircraft or live connection. Check the operating airline’s flight details for equipped aircraft and the onboard portal for current availability. Sources were checked 28 October 2026.
Understand the numbers
Nautical miles are the default. You can switch to statute miles or kilometers at any time. One nautical mile equals 1.852 kilometers. For a multi-stop itinerary, Airpath adds the distance of each leg; a set of alternative itineraries shows the combined total with separate details below the map.
The added distance is the modeled route minus its great-circle baseline. A zero detour means the model found the direct path clear of your chosen regions. It does not establish that an airline can fly that exact track.
Ranges are distance budgets, not flight-time or fuel predictions. With exclusions, the filled area considers the extra distance needed to travel around them. A location may be inside the dashed great-circle radius yet outside the reachable area when a detour uses up the budget.
How the estimate is made
The model uses a spherical Earth and a 1° global routing grid. It checks grid connections against excluded polygons, then removes unnecessary bends using collision-checked great-circle shortcuts. This can produce a useful feasible approximation without guaranteeing a globally shortest solution. A coarse grid may overestimate a detour or miss a narrow passage. Range outlines have the same approximate grid resolution.
Airways, winds, weather, aircraft performance, current NOTAMs, ATC instructions, operator permissions, diversion requirements, and departure or arrival procedures are not modeled. These factors matter for actual flown distance. The in-app “Method & data” panel provides additional detail.
Data and independence
Airport coordinates come from OurAirports. Country land outlines come from Natural Earth. Advisory references link to EASA, where you should consult the current original bulletins. City coordinates and names come from GeoNames under CC BY 4.0, downloaded 27 October 2026. This map rounds coordinates and retains selected name aliases; the city asset is a modified extract. City, airport, DC-area and map data are bundled with this version of the site.
Airpath is an independent visualization tool. It is not affiliated with or endorsed by GCMap, any airline, OurAirports, or EASA.