Hydroplaning Speed Calculator
Estimate the dynamic hydroplaning speed from tire pressure — the ground speed on a wet or flooded runway where the tires can ride up on a film of water.
Hydroplaning speed (spin-down / rolling)
49 kt
Onset on touchdown (spin-up)
42 kt
Dynamic hydroplaning speed ≈ 9 × √(tire pressure) for a rolling tire, and ≈ 7.7 × √(pressure) for a non-rotating tire at touchdown (NASA/Horne). On a wet, flooded or contaminated runway near these speeds the tires can ride on a film of water — reduced braking and steering. A reference figure only; actual onset depends on water depth, tread and runway texture.
How this works
From NASA/Horne, dynamic hydroplaning speed depends on tire pressure:
Vp ≈ 9 × √(tire pressure in psi) for a spinning (rolling) tire, and about 7.7 × √(psi) for a non-rotating tire spinning up at touchdown.
Near these speeds on a flooded runway, braking and directional control degrade sharply. It is a reference figure only — actual onset depends on water depth, tread depth, and runway surface texture/grooving. Fly the numbers and technique in your AFM/POH.
For reference and training only. Not for navigation or flight planning — always verify against official current sources.