Aviation Calcs

Approach / landing speed

Approach and Landing Speed Calculator

Most POH and AFM landing speeds start from a reference approach speed of 1.3 times the stall speed in the landing configuration (Vso), then add a gust factor. Enter Vso, optionally a weight different from the book weight, and the reported wind and gust. The FAA / Airplane Flying Handbook additive is half of the gust increment (gust minus the steady wind). A transport-category ½-headwind-plus-full-gust method is shown only if you enter a headwind, and is labeled as such.

Use the stall speed for the landing flap and gear configuration from the POH/AFM, in the same units as the other speeds on this page.

usually 1.3

Vref = factor × Vso. 1.3 is the usual light-airplane and training definition. A few transport manuals use a slightly different number (for example 1.23); enter that if your AFM says to.

optional
optional

When both weights are entered, Vso is scaled by √(W / Wref) before applying the 1.3 factor — the same weight rule as the stall-speed calculator. Units only have to match each other.

optional
optional

FAA / AFH gust factor: additive = ½ × (gust − steady wind). The steady wind itself is not added to indicated approach speed; it already appears as a lower groundspeed.

optional, transport method
kt equivalent

Some transport operators add ½ the headwind component plus the full gust increment, often capped at 20 kt. That figure is reported separately and is not the AFH method.

Approach speed

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Vref = 1.3 × Vso

For most light airplanes, the reference landing approach speed is defined as 1.3 times the stall speed in the landing configuration. If the POH quotes Vso = 40 kt, Vref is 52 kt. That 1.3 factor is the usual training and certification reference (a 30% margin above stall in 1-g, wings-level flight). A few transport AFM procedures use a slightly different factor, such as 1.23; if yours does, type it in the factor box.

Stall speed — and therefore Vref — also changes with weight. The same square-root rule used on the stall-speed calculator applies: multiply Vso by √(W / Wref) before applying 1.3 when you will land lighter or heavier than the book weight that goes with the published Vso. Leave the weight boxes blank if you are flying at the POH weight.

The FAA gust factor

The Airplane Flying Handbook, and many POH landing procedures, add half of the gust increment to the approach speed. The gust increment is the difference between the reported gust and the steady wind. In a wind of 15 gusting 25, the increment is 10 kt and the additive is 5 kt, so a 52 kt Vref becomes a 57 kt approach speed. The steady wind is not added to indicated airspeed — it already reduces groundspeed on short final.

Some transport operators use a different additive: half the headwind component plus the full gust increment, often with a cap (commonly 20 kt). If you enter a headwind, this page will also compute that number and label it as the transport method, so it is not confused with the AFH half-gust rule.

Sources

FAA Airplane Flying Handbook (approach and landing, gust factor); FAA Pilot's Handbook of Aeronautical Knowledge; typical POH/AFM definition of Vref = 1.3 Vso; stall-speed weight scaling as used on this site's stall speed vs weight and bank calculator. For a wet-runway speed check, see hydroplaning speed. For correcting a book landing distance, see takeoff and landing distance.

Frequently asked questions

What is Vref if Vso is 40 knots?

1.3 × 40 = 52 knots, at the weight that goes with that Vso. If you will land at a different weight, scale Vso by √(W/Wref) first.

How does the FAA gust factor work for 15 gusting 25?

The gust increment is 25 − 15 = 10 knots. The Airplane Flying Handbook additive is half of that, or 5 knots, added to Vref. The 15-knot steady wind is not added to indicated approach speed.

Should I also add half the headwind?

Not under the usual AFH / light-airplane procedure. Some transport SOPs add ½ the headwind plus the full gust increment, often with a 20-knot cap. This page will show that method only if you enter a headwind, and it is labeled as the transport method.