Enter degrees and decimal minutes (DD° MM.M′), for example N68 59.4 and W060 36.9. Use N/S for latitude and E/W for longitude. Leading zeros are accepted.
02 · Aircraft and wind
TAS is used for the calculation. Mach is an optional reference only; it is not converted to TAS. Wind direction is entered as degrees TRUE, FROM.
03 · Equal time point
ETP position · Degrees and decimal minutes
—
—
Time either way—
Route distance—
Distance from departure—
Distance to destination—
Outbound GS at ETP—
Return GS at ETP—
DepartureETPDestination
Operational limitation: This is an independent planning aid, not an approved EFB, flight-planning system or operational source. It assumes constant TAS and a spatially uniform wind, no route changes, and a return along the same great-circle track. Verify independently against approved company procedures, aircraft performance data and current operational weather before any use. Do not use this prototype for dispatch or in-flight decision-making.
Model: spherical great-circle route sampled in short segments; wind corrected for along-track and crosswind components; time from ETP to departure is compared with time from ETP to destination. Earth radius: 3,440.065 NM. Inputs use degrees and decimal minutes (e.g. N68 59.4 W060 36.9). This version does not model temperature/altitude changes, acceleration, turn geometry, drift-down, terrain, airspace, fuel, or forecast wind variation.