Every governing equation RotorLab uses, derived and referenced. Each one is also re-evaluated independently in your browser from the inputs below and checked against what the engine returns from its own code path. If a card shows matches engine, the printed equation and the software agree to within 0.1%. A card showing differs indicates a discrepancy between the documented equation and the engine. Pick an airframe — a multirotor, a VTOL transition, or a fixed wing — and watch every number recompute. The quadplane and tiltrotor VTOLs combine these two: the hover model for their lift rotors and the wing-borne model for cruise.

References

• Leishman, J. G. Principles of Helicopter Aerodynamics, 2nd ed. Cambridge University Press, 2006. Actuator-disc / momentum theory for hover and forward flight.
• U.S. Standard Atmosphere, 1976. NOAA/NASA/USAF. Pressure and density lapse used for density altitude.
• Anderson, J. D. Fundamentals of Aerodynamics. McGraw-Hill. Lift, the drag polar, stall, and the power-required / rate-of-climb relations for the wing-borne model.
• McCormick, B. W. Aerodynamics, Aeronautics, and Flight Mechanics. Propeller thrust coefficient form T = C_T ρ n² D⁴.

This page computes a first-order, sizing-grade model. It is a transparent statement of what the software does, not a claim that the model captures every real-world effect. Measured thrust-stand and flight data remain definitive. See the model limitations in the project README.