Aircraft Factor Calculator

Aircraft Engineering Calculator — SI units

Enter aircraft geometry/flight conditions. Defaults provide a small commuter-type example (6,000 kg, 30 m² wing).

Inputs

Mass (kg)

Wing area S (m²)

Wing span b (m)

Mean aerodynamic chord c (m)

Cl (cruise)

Cl_max (flaps/down)

Cd0 (zero-lift)

Induced drag factor k

Air density rho (kg/m³)

Flight speed V (m/s)

Specific fuel consumption c (1/s) — Breguet (jet)

Propulsive efficiency eta (for power to fuel)

Initial fuel fraction Wi/Wf (for range)

Results

— Weight (N)

Wing loading: N/m²

Aspect ratio (AR):

Lift @ V: N

Equilibrium check (Lift - Weight): N

Stall speed Vs (Cl_max): (m/s) ≈ km/h ≈ kt

Reynolds number Re (based on chord):

Parasite drag D0 = 0.5·rho·V²·S·Cd0 : N

Induced drag Di = 0.5·rho·V²·S·k·Cl² : N

Total drag D = D0 + Di : N

Required thrust (≈ total drag) : N

Required power P = T·V : W ≈ kW

Breguet range R ≈ (V / c)·(L/D)·ln(Wi/Wf) : m ≈ km

Simple takeoff ground roll (approx): m

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Formulas used

Weight W = m·g   (g = 9.80665 m/s²)

Lift L = 0.5·rho·V²·S·Cl
Stall speed Vs = sqrt( (2·W) / (rho·S·Cl_max) )

Wing loading = W / S
Aspect ratio AR = b² / S
Reynolds Re = (rho·V·c) / mu  (assumed mu = 1.7894e-5 Pa·s for air at 15°C)

Parasite drag D0 = 0.5·rho·V²·S·Cd0
Induced drag Di = 0.5·rho·V²·S·k·Cl²
Total drag D = D0 + Di

Required thrust ~ D
Power required P = D · V

Breguet (jet) R = (V / c) * (L/D) * ln(Wi/Wf)
  where c is fuel consumption in 1/s (e.g. TSFC in 1/s) and Wi/Wf is initial/final weight ratio.

Takeoff roll (very approximate):
  s ≈ (W/S) / (rho·g·(T/W - mu_r)) * factor
  (we use a simpler energy-based approximation in the script)
  -- This is an estimate for level ground, no slope, and no obstacles.