Aviation Calcs

Maneuvering speed

Maneuvering Speed vs Weight Calculator

Design maneuvering speed decreases as the airplane gets lighter: Va(W) = Va_ref × √(W / W_ref). Enter the POH figure and the weight it was published at, plus the weight you will fly, and get the scaled Va. You can also estimate Va from a stall speed and a limit load factor (3.8 normal, 4.4 utility, 6.0 aerobatic — always defer to the book).

Speeds are in whatever unit the POH uses (usually KIAS). Weights are in the same unit as each other (usually lb).

If you omit published Va but enter Vs and n, Va is estimated as Vs × √n at the reference weight, then scaled. Typical Part 23 positive limit load factors are 3.8 (normal), 4.4 (utility), and 6.0 (aerobatic).

Va at this weight

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Why Va falls when you are light

Maneuvering speed is, in the usual training explanation, the highest speed at which a full, abrupt control input or a sharp gust should stall the wing before it reaches the limit load factor. Stall speed itself falls with the square root of weight, so Va does too:

Va(W) = Va,ref × √(W / Wref)

and, when a level-flight stall speed and a positive limit load factor nlim are known,

Va ≈ Vs × √nlim

A 172-class example: if Va is 105 KIAS at 2,550 lb, then at 2,200 lb it scales to 105 × √(2200/2550) ≈ 97.5 KIAS. Flying the gross-weight Va when you are light means you can, in principle, reach the limit load factor before the wing stalls.

What Va is not

Va is not automatically the recommended turbulence-penetration speed (that may be a different published speed). It does not authorize abrupt full-deflection inputs in both axes at once, and some airplanes have demonstrated that certain control inputs at Va can still overstress a surface. Always read the POH language for your type.

Sources

FAA Pilot’s Handbook of Aeronautical Knowledge, Chapter 5 (load factor, Va); FAA Airplane Flying Handbook; 14 CFR Part 23 limit maneuvering load factors (historical / applicable amendment). For stall speed versus weight and bank, see the stall speed calculator.

Frequently asked questions

Do I ever increase Va above the published gross-weight figure?

Not above the POH limit. If you are heavier than the weight at which Va was published — which you should not be, if that weight is max gross — the identity would scale Va up, but the structural limit in the book still applies. This page will still do the math and flag that the weight is above the reference.

Is the 3.8 load factor universal?

No. 3.8 is the usual positive limit for a normal-category Part 23 airplane; utility is typically 4.4 and aerobatic 6.0. Some types differ. Use the POH.

KIAS or TAS?

Published Va is an indicated (or calibrated) airspeed. Scale it as a speed in the same unit the book uses; do not convert to TAS first.