🛩️ Paper Airplane Lift & Drag Analysis (2D)

This 2D companion drives real fixed-wing flight dynamics from the side: a thin-airfoil lift curve (Cl ≈ 2π·α, softly stalling past the critical angle of roughly 15°) and a parasitic-plus-induced drag polar, both functions of angle of attack, feed a Runge–Kutta integration of the full equations of motion — gravity, lift perpendicular to the velocity, drag opposite it — so the glide path you see is computed, not drawn. Four launch parameters — wing area, launch speed, launch angle and initial angle of attack — all measurably change the trajectory, and pushing the angle of attack past the critical angle triggers a genuine aerodynamic stall: lift collapses, the flight path falls away from the plane's fixed pitch attitude, and it drops instead of gliding, with a live glide-ratio (L/D) readout and a stall flag confirming exactly when it happens.