GSV1 — Groundspeed V1 Gate

InputsExact method

Wind reference

Method

Wind & runway—

360°M

0 25 50 75

drag runwaydrag wind directiondrag ring for speed

Runway component

—

Crosswind

—

Wind speed

0 kt

Wind (magnetic)

—

Groundspeed V₁ gate · brief this

—kt

—

If wind shear is positively identified

V_GS ≤ — REJECT

V_GS > — CONTINUE

Monitor performance, follow operator SOPs

Hazards

Load an airport to check wind shear hazards

Derived

W∥ runway wind

—

headwind −, tailwind +

W⊥ crosswind

—

TAS at V₁

—

Density ratio σ

—

Δ compressibility

—

Mach

—

Pressure altitude

—

Density altitude

—

Runway heading

—

This tool does not supersede AFM/FCOM/SOPs · Provided as-is without warranty or liability

Data: AVWX (METAR/TAF) · NOAA AWC (CWA, G-AIRMET, SIGMET, PIREP, TCF) · NWS · FAA NMS (NOTAMs) · ATIS · NOAA Geomag

How to use this calculator

What it does. Converts your V₁ from indicated airspeed to groundspeed for today's conditions, giving a groundspeed decision gate for a wind shear encounter on the takeoff roll.

Load the airport (ICAO or IATA). Temperature, QNH, elevation, wind, magnetic variation and the runways in use fill in from METAR, ATIS and NOAA; every hazard product is checked.
Set V₁ from your performance data. Wind speed should match what the performance calculation used — gusts are shown for awareness only.
Verify the runway and wind. Drag on the dial to adjust: the green dot is the start of the takeoff roll, the chevrons point toward the runway heading.
Brief the gate: if IAS stagnates with wind shear positively identified, V_GS at or below the gate means reject.

Tip: touch and hold any item for an explanation.

Exact method applies the full atmospheric model (density, compressibility, TAS). Simplified uses the k-factor approximation. This tool does not supersede AFM/FCOM/SOPs.