Free RC Airplane Wing Loading Calculator
Calculate aerodynamic wing loading, Wing Cube Loading (WCL), flight category envelope, and true stall speed.
✈️ Aircraft Weight & Wing Area
📊 Flight Characteristics & Stall Speed
Recommended Tools & Equipment
Tested hardware and components for high reliability
Wing Loading vs. Wing Cube Loading (WCL)
Traditional Wing Loading (oz/ft² or g/dm²) compares weight to surface area. However, because weight scales with volume (cubed) while wing area only scales with surface (squared), larger aircraft naturally possess much higher wing loading numbers while still flying gently. Wing Cube Loading (WCL) normalizes for scale, allowing direct comparison between a 200g micro parkflyer and a 15kg giant-scale warbird.
Aerodynamic Equations
Wing Cube Loading (WCL) Flight Envelopes
| WCL Range | Aircraft Classification | Flight Handling |
|---|---|---|
| < 4 | Thermal Gliders / Indoor Micro | Floating, self-correcting, virtually impossible to stall |
| 4 – 7 | Trainers / Gentle Parkflyers | Predictable, slow landings, forgiving stalls |
| 8 – 11 | Sport Aerobatics / 3D | Crisp roll rates, vertical climbs, requires active throttle control |
| 12 – 16 | Scale Warbirds / Racers | Fast fly-bys, long takeoff runs, prone to high-speed tip stalls |
| > 16 | Ducted Fan Jets (EDF) / Heavy Scale | Hot landings, severe stall danger during steep banking turns |
Frequently Asked Questions
Why does stall speed increase during a banked turn?
To maintain altitude in a turn, the wings must generate enough total lift to support both gravity and the centripetal acceleration. In a 60-degree banked turn, the load factor is 2G (1 / cos(60°) = 2.0). Because stall speed is proportional to the square root of the load factor (sqrt(2) approx 1.414), an airplane that stalls at 20 mph level will stall at 28.3 mph in a 60° bank.
What causes tip stalls in heavy scale warbirds?
Tapered wings (narrower chord at the wingtips) create high localized lift coefficients near the tips. Combined with high wing loading, the wingtip airfoils reach their critical angle of attack (CLmax) before the wing root, suddenly dropping a wing and sending the aircraft into an unrecoverable low-altitude spin. Adding aerodynamic wash-out (twisting wingtips downward 2-3 degrees) cures this.
Does density altitude affect stall speed?
True Airspeed (TAS) stall speed increases with altitude or high temperatures because air density decreases. However, Indicated Airspeed (IAS) stall speed remains unchanged because airspeed pitot sensors measure dynamic pressure (q = 0.5 * rho * V^2), which directly matches wing lift generation.