MachineCalcs

Stall Margin Calculator

Check available load factor and airspeed margin above accelerated stall speed.

Calculator

km/h

km/h

g

Results

Default result
Edit inputs
Available load factor before stall
3.24g
Pass

Also computed

Planned accelerated stall speed131.0km/h

Airspeed marginPass35.7km/h

Load-factor margin1.24g

Method notes 2 notes
  • Uses n_available = (V / Vs)^2 and Vs_n = Vs * sqrt(n).
  • This is an arithmetic margin screen only; angle of attack, configuration, CG, turbulence, control inputs and aircraft limitations matter.

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All Aviation

How to use this calculator

  1. Enter current airspeed. Use the speed for the condition being screened.
  2. Enter 1g stall speed. Use the matching configuration and weight.
  3. Enter planned load factor. Use the g loading you want to compare.
  4. Read margin. Positive speed and load-factor margins mean the arithmetic screen is above stall.

How it works

Available load factor is n_available = (V / Vs)^2. Planned accelerated stall is Vs_n = Vs x sqrt(n).

Pair it with accelerated stall, bank angle from load factor and maneuvering speed.

Worked example

Verified against the live calculator

At 90 kt with a 50 kt 1g stall speed, available load factor is (90 / 50)^2 = 3.24 g. Against a planned 2 g load, stall speed is 70.7 kt and margin is 19.3 kt.

Frequently asked questions

What is stall margin here?

It is the difference between current airspeed and the accelerated stall speed for the planned load factor.

How is available load factor calculated?

The calculator uses n_available = (V / Vs)^2.

Does this know angle of attack?

No. It is an airspeed/load-factor screen, not an angle-of-attack or flight-test model.

Can this replace aircraft procedures?

No. It is for arithmetic screening only.

Method & assumptions

  • Uses only airspeed, 1g stall speed and planned load factor.
  • Does not model angle of attack, turbulence, slips/skids, CG, flap effects or aircraft limitations.
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