Calculator Inputs
This page uses a single stacked layout, while the calculator form switches to three columns on large screens, two on medium screens, and one on mobile screens.
Plotly Graph
This graph shows how stall speed rises with bank angle for the current weight, wing area, density, and lift coefficient.
Chart speeds are shown in knots.
Example Data Table
These sample values help verify the calculator and illustrate typical engineering use.
| Case | Weight (N) | Wing Area (m²) | CLmax | Density (kg/m³) | Bank (°) | Clean Stall (kt) | Condition Stall (kt) | 1.30 × Condition Stall (kt) |
|---|---|---|---|---|---|---|---|---|
| Trainer aircraft sample | 10,668 | 16.2 | 1.50 | 1.225 | 30 | 52.04 | 55.92 | 72.70 |
| Higher-lift configuration sample | 14,000 | 17.5 | 1.90 | 1.180 | 20 | 51.93 | 53.57 | 69.64 |
Formula Used
The calculator applies the classical lift-equals-weight stall relation, then adjusts it for maneuver load factor.
Vs = √(2W / (ρS CLmax))
n = 1 / cos(φ)
Vs,condition = Vs × √n
Vrecommended = Vs,condition × Safety Factor
W = aircraft weight force, ρ = air density, S = wing area, CLmax = maximum lift coefficient, φ = bank angle, n = load factor.
How to Use This Calculator
- Enter aircraft weight using a force unit such as N, kN, lbf, or kgf.
- Enter wing area and choose the matching area unit.
- Provide an appropriate CLmax for the selected aircraft configuration.
- Enter air density for the flight condition you want to evaluate.
- Choose whether maneuver effects come from bank angle or direct load factor.
- Set a safety factor to estimate a conservative operating speed.
- Optionally enter a reference speed to compare your chosen speed against stall.
- Press the calculate button to display results above the form and update the graph.
This tool is suitable for study, preliminary engineering checks, and training examples. It is not a substitute for approved aircraft performance data.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates clean stall speed, turning or maneuver stall speed, and a recommended minimum operating speed using a chosen safety factor and optional reference speed check.
2) Why does stall speed increase in a turn?
A banked turn raises load factor. The wing must produce more lift, so the aircraft reaches CLmax at a higher airspeed.
3) Which weight should I enter?
Enter aircraft weight as force, not mass. If you only know mass, convert it to force first or use a compatible force unit such as kgf.
4) What value should I use for CLmax?
Use a configuration-specific value from trusted aerodynamic data, wind tunnel data, manufacturer references, or validated design assumptions for the selected flap and gear setting.
5) How important is air density?
Air density strongly affects the result. Lower density increases true stall speed, so altitude, temperature, and atmospheric conditions matter during engineering evaluation.
6) What safety factor is common?
A factor near 1.30 is commonly used for reference-speed style checks, but your actual requirement depends on aircraft type, regulations, and operational procedures.
7) Can I use load factor directly?
Yes. Select direct load factor when you already know n from maneuver analysis, simulation, or structural loading calculations rather than from bank angle.
8) Is this calculator suitable for certified flight planning?
No. It is a study and engineering aid. Always use approved aircraft documents, validated performance charts, and official operating procedures for real operations.