#flight-planning

Aircraft fuel-planning maths as an API, computed locally and deterministically — the endurance, range and fuel-required numbers a pilot, dispatcher or flight-sim developer plans a flight with, all honouring a reserve. The endurance endpoint gives how long you can fly = usable fuel ÷ burn rate, holding back a reserve (30 min day / 45 min night VFR, 45 min IFR is typical), so the usable endurance is the time you can actually plan to rather than the tanks-dry figure — 50 gallons at 10 gph is 5:00 total but 4:15 usable on a 45-minute reserve. The range endpoint turns that into distance = usable endurance × ground speed, so it lives or dies on the wind: a headwind cuts the ground speed and the range while burning the same fuel per hour, which is why you plan on the forecast ground speed, not the true airspeed. The fuel-required endpoint sizes the load for a leg = trip time × burn plus the reserve — 300 nm at 120 kt and 10 gph needs 25 gallons of trip fuel plus 7.5 reserve, 32.5 total — to which a real flight adds taxi and climb allowances. Everything is computed locally and deterministically, so it is instant and private. Ideal for flight-planning and EFB apps, dispatch and flight-school tools, flight-simulator utilities, and general-aviation calculators. Pure local computation — no key, no third-party service, instant. Add taxi/climb and a personal margin; confirm against tank capacity and weight-and-balance. 3 compute endpoints. For glide range use a glide-ratio API; for density altitude a density-altitude API.

api.oanor.com/fuelburn-api

Aircraft glide-performance maths as an API, computed locally and deterministically — the glide-distance, glide-ratio and reachability numbers a pilot, flight-instructor or flight-sim developer works an engine-out or soaring problem with. The glide-distance endpoint gives the still-air distance you can cover = height above the ground × the glide ratio (L/D): from 5,000 ft at a 9:1 ratio you reach about 45,000 ft, ~7.4 nm, with the answer in feet, nautical miles and kilometres. The glide-ratio endpoint reads the slope straight off the polar — glide ratio = forward speed ÷ sink rate (1 knot ≈ 101.27 ft/min), so 60 kt at a 600 ft/min sink is about 10:1, a 5.6° glide path — and gliders reach 40–60:1, a light single ~9:1, an airliner ~17:1. The reach endpoint answers the practical question: the height needed to reach a field = distance ÷ glide ratio, the arrival height is what is left, and it only counts as making it if that clears a safety reserve (default 1,000 ft) for the circuit and approach. Everything is computed locally and deterministically, so it is instant and private. Ideal for flight-planning and EFB apps, gliding and soaring tools, flight-simulator and training utilities, and aviation-safety calculators. Pure local computation — no key, no third-party service, instant. Still-air estimates — adjust for wind, configuration and a margin. 3 compute endpoints. For density altitude use a density-altitude API; for runway wind components a crosswind API.

api.oanor.com/glideratio-api

Aviation atmosphere maths as an API, computed locally and deterministically using the exact International Standard Atmosphere relations — the numbers a pilot, dispatcher or flight-planning tool needs before take-off, not a rough rule of thumb. The density-altitude endpoint turns the field elevation, altimeter setting and outside air temperature into the pressure altitude (elevation + (29.92 − setting) × 1000) and then the density altitude — the altitude the air actually feels like to the wings and engine — computed from the true ISA density ratio rather than the approximate 120-foot-per-degree rule, with the ISA temperature deviation: on a hot, high day the density altitude soars, robbing lift and thrust and lengthening the take-off roll, the classic mountain-airport hazard. The true-airspeed endpoint gives TAS from calibrated airspeed as CAS ÷ √(density ratio), so the navigator gets the real speed through the air that climbs above the indicated reading with altitude and temperature. The isa endpoint returns the standard-atmosphere temperature, pressure, pressure and density ratios and the speed of sound at any altitude in the troposphere — the reference every altimeter, performance chart and engine rating is built on. Everything is computed locally and deterministically, so it is instant and private. Ideal for flight-planning and EFB apps, drone and UAV tools, aviation weather dashboards, and aerospace-engineering utilities. Pure local computation — no key, no third-party service, instant. Troposphere (≤ 36,089 ft); incompressible TAS. 3 compute endpoints. For the speed of sound and Mach use a Mach-number API; for runway wind components a crosswind API.

api.oanor.com/densityaltitude-api