Flight Planner
Origin, destination, and your aircraft numbers: distance, heading, ground speed, ETE, and fuel with real winds aloft sampled along the route, and the altitude the winds favor.
What the planner does
It computes the great circle course and distance between any two US airports, then corrects it for the real atmosphere: the NOAA winds and temps aloft forecast is sampled at up to 12 points along the route at your cruise altitude, each segment gets its own wind triangle, and the segment times add up to the ETE and fuel figures. The result line names every forecast station it used.
The altitude sweep
Because each forecast sample includes the full ladder from 3,000 to 53,000 ft, the planner also evaluates every legal cruising altitude for your direction, hemispheric VFR altitudes below 18,000 ft and IFR flight levels up to FL410 within your aircraft's max altitude. When another altitude is meaningfully faster, one click replans at it. The sweep assumes your TAS holds at every altitude, so treat it as a winds comparison, not a performance chart.
The cross-section
Under the numbers is a side view of the route: distance runs along the bottom, altitude up the side, and everything is drawn where it actually sits. Cloud layers come from reporting stations within 50 NM of the course, converted from the height above ground that a METAR reports to height above sea level. SIGMET and G-AIRMET areas appear as bands across the stretch of route they cover. The freezing level is interpolated from the forecast temperatures in the same winds aloft data that drives the ETE, so it is a forecast rather than an estimate from the surface temperature. Beside the plot, the time to fly at every candidate altitude shares the same altitude scale, so the fastest altitude and the weather at that altitude are one glance apart.
What this tool does not show
Terrain. The shaded ground is the highest airport or heliport near each stretch of the route, which is the best proxy a national airport database can give. Real ridges between those landing sites are higher, often by thousands of feet in the mountain west. Nothing here is terrain clearance, minimum en route altitude, or obstacle data: use a sectional or a terrain aware EFB for that. The cross-section also draws only what stations and pilots have reported, so a stretch with no reporting station is empty because nobody looked, not because it is clear. It is not a substitute for an official weather briefing, and it does not cover NOTAMs or TFRs.
FAQ
Where does the wind data come from?
The NOAA winds and temps aloft forecast (the FB product), which reissues four times a day. The planner samples it along your route, one point per roughly 50 NM, and flies the wind triangle for each segment.
How does the best altitude suggestion work?
Every legal cruising altitude for your direction of flight, VFR altitudes below 18,000 ft and IFR flight levels up to FL410 within your max altitude, is evaluated against the same forecast. When one beats your chosen cruise by two minutes or more, the planner offers it.
Is this a legal flight plan or briefing?
No. It is an advisory planning estimate on a great circle course. File and brief through official channels; the FAA standard briefing covers weather, NOTAMs, and TFRs that this tool does not.
Are courses magnetic or true?
Both: the magnetic course uses the origin airport's FAA published magnetic variation, with the true course beside it. A few fields without NASR data fall back to true only.
Does the cross-section show terrain?
No. The shaded ground is the highest airport or heliport near each part of the route, not surveyed terrain, and ridges between landing sites are higher — often by thousands of feet in the mountain west. Use a sectional or a terrain-aware EFB for terrain and obstacle clearance.
Why is part of my route empty on the chart?
The cross-section draws what has actually been reported. Cloud layers come from weather stations within 50 NM of the course and pilot reports come from the last 90 minutes, so a quiet stretch means nobody reported there, not that the air is clear.
The calculator is just the start
These same calculations power the SkyReady app — alongside an offline-first logbook, automatic FAA currency, proficiency scoring, and a one-tap Go/No-Go readiness brief. Free to log.