How JetDesk computes trip cost
The Trip tab turns a list of airport codes into a number with a dollar sign. Here is exactly how, so you can tune the inputs to your airplane and trust the result.
01Distance
Great-circle distance between airport reference points, in nautical miles, from the FAA airport file. No routing, no airways, no SIDs. For a light turboprop flying direct or near-direct in the Northeast, real tracks run 2 to 5 percent longer; add block overhead (below) to cover it.
02Speed and winds
Cruise true airspeed comes from Settings. With Pro, JetDesk pulls the FAA winds aloft forecast (FB) for the station nearest each leg at your cruise altitude, interpolates between forecast levels, solves the wind triangle, and uses the resulting groundspeed. Without winds, it uses your KTAS as is. The leg card shows the wind used and its source station.
03Time
Block time = distance ÷ groundspeed + block overhead. The overhead (12 minutes by default) covers taxi, climb below cruise speed, descent, vectors and the approach. Tune it to your operation; a Meridian into Westchester on a Friday deserves more than 12.
04Fuel
Burn = block time × cruise gallons per hour + taxi and takeoff gallons. Both come from Settings, and the presets load typical figures. Cruise burn is the number to get right: it is 80 percent of the answer.
05Cost
Cost = burn × the planning price per gallon. The planning price is a single number for the whole trip (edit it right on the Trip tab), because a trip cost estimate is for budgeting, not for a fuel receipt. The Fuel Stop tab is where airport-specific prices matter.
06What is left out on purpose
- Landing, ramp, handling and overnight fees. They vary by FBO and by whether you buy fuel; log them in the FBO notes.
- Engine reserves, maintenance accruals and crew costs. Add them to the owner brief notes if the owner wants the fully loaded number.
- Alternate fuel and reserves. The estimate is burn to destination; your dispatch fuel is a different conversation.
07Runway verdicts on the leg
Each leg grades the arrival airport's best runway: wide open at 5,000 × 100 ft or better, workable at 4,000 × 75, tight below that. Those are comfort labels based on runway size. The airport page adds real distance estimates for your airplane corrected for density altitude and wind; read the density altitude note for how those work.
08The owner brief
Pro accounts can share a trip as a clean one-page brief: legs, miles, block, gallons and cost, with the price basis stated. It is a link that prints, meant to be sent to the owner before the trip so the number is agreed before the fuel is bought.
More field notes
Reserve fuel, and the alternate nobody plans
How JetDesk decides whether a leg makes reserve, and why the alternate is where most fuel stops really come from.
Why block time swings twenty minutes
How the FAA winds aloft forecast becomes a groundspeed for each leg, and why the return leg costs more than the outbound one.
Weight before fuel: payload runs out first
Zero fuel weight, max fuel by weight and landing weight for a Piper Meridian with five aboard, and how JetDesk shows it per leg.