Range & Fuel Help V20.4

1. Overview

Range & Fuel is an interactive planning aid for visualising aircraft range, trip fuel, great-circle routing, upper-level wind effects and suitable airports. V20.4 combines aircraft performance profiles, airport/runway data, forecast winds and optional 18-month historical wind analysis.

Important: Planning aid only. It is not an approved navigation, dispatch, aircraft-performance or weather system. Always use current official aeronautical, aircraft, weather and operational information for an actual flight.

2. Range & Fuel

Function	Description
500 / 1,000 / 1,500 NM	Fixed geographic reference rings centred on DEP.
Fuel Range	Still-air range using the selected aircraft profile, fuel, taxi/climb allowance and 45-minute reserve.
Wind-corrected Range	Directional range using the selected wind. Headwind reduces and tailwind increases effective range.
Great Circle	DEP → DEST and DEST → ALT route geometry and distance.
Trip Calculator	Distance, estimated time, trip fuel, fuel at destination, reserve and planning status.

3. Forecast & Manual Wind

The Wind selector supports Manual, Forecast +24 h, +48 h, +72 h and Date & Time. Upper-level winds are obtained for pressure levels corresponding approximately to the selected cruise FL. Wind is resolved relative to route track, so the forecast range is directional rather than simply circular.

4. Historical Wind — HIST 18M

HIST 18M analyses approximately 18 months of historical upper-level winds for the current DEP–DEST route and selected FL. V20.4 samples 7 points along the great-circle route at 00, 06, 12 and 18 UTC. Data are loaded month-by-month and results are cached locally.

Metric	Meaning
MAX HW	Strongest historical headwind found in the analysed sample; an extreme value.
P95 HW	95th percentile of headwind magnitude: about 95% of sampled headwind cases were at or below this value and about 5% were stronger.
P95 TW	95th percentile of tailwind magnitude: a strong historical tailwind reference without relying on the single absolute maximum.
MAX TW	Strongest historical tailwind found in the analysed sample.

Why P95? A maximum can be dominated by one exceptional weather situation. P95 provides a high-end statistical reference that is generally more representative than the single most extreme observation.

Historical range rings

After a successful HIST 18M calculation, four dash-dot historical range rings are available. P95 Headwind and P95 Tailwind are enabled by default; Max Headwind and Max Tailwind are initially disabled. Each ring can be switched on or off individually in the map legend. These are historical scenario visualisations, not future-weather forecasts.

5. Airport Search & Filters

DEP, DEST and ALT can be searched by ICAO code, airport name or locality. Nearby-airport lists can also be generated from map/address searches.

Function	Description
Minimum runway	Uses the selected aircraft's hard-runway requirement where available.
Civil only	Suppresses airports classified as military by the available airport data/logic.
IFR	The loaded database identifies an instrument procedure.
VFR	In this planner, no IFR procedure is identified in the loaded data.
Alternate Finder	Finds suitable alternate candidates around DEST subject to active filters.

Point of Entry / customs filtering is not implemented in V20.4 because the current database does not yet provide sufficiently reliable worldwide data for it.

6. URL Parameters

Parameter	Example	Purpose
`ICAO`	`?ICAO=LSZS`	Sets DEP.
`TYPE`	`?TYPE=TBM8`	Selects by ICAO aircraft type; one type may cover several variants.
`AIRCRAFT`	`?AIRCRAFT=TBM960`	Selects the exact aircraft model.

Example: ?ICAO=LSZS&AIRCRAFT=TBM960. Valid URL values take priority over saved/default selections.

7. Glossary

Term	Meaning
DEP / DEST / ALT	Departure / Destination / Alternate.
FL	Flight Level.
NM	Nautical miles.
KT / KTS	Knots.
USG	US gallons.
HW / TW	Headwind / Tailwind component.
P95	95th percentile: 95% of the relevant sampled values are at or below this level.
Great Circle	Shortest route between two points on a spherical Earth model.
Pressure Level	Atmospheric pressure surface in hPa used for upper-air wind.
IFR / VFR	Instrument / Visual Flight Rules; the planner classification depends on procedure information in its database.

8. Data, Cookies & Limitations

Aircraft performance and airport information are loaded from the accompanying JSON data; configuration/branding can be supplied through Range.ini. Preferences, consent and historical-wind cache data can be stored locally in the browser.

Results depend on the accuracy and completeness of aircraft profiles, fuel input, airport data and weather data. Runway length alone does not establish take-off or landing suitability. The tool does not replace AFM/POH calculations, NOTAMs, charts, operational approvals, fuel-policy requirements, customs/immigration information or an official weather briefing.