Steady, unaccelerated flight at FL300. Lift equals weight, thrust equals drag. Confirm that L = W and T = D. Note the angle of attack and the L/D ratio.
Hover or tab onto CG, CP, AC, NP or the thrust line for an explanation.
γ = 0° · L = W and T = D at equilibrium
W = m × g = 64,000 kg × 9.807 = 627.6 kN
Excess thrust = T available − T required = 45.5 kN
Flaps
AR = b² / S = 35.8² / 124.6 = 10.29
Wing loading 514 kg/m² · 5.04 kPa
Ailerons → roll (longitudinal) · Elevator → pitch (lateral) · Rudder → yaw (vertical)
Roll is visible in the front view, yaw in the top view and pitch trim in the side view.
L = ½ ρ V² S C_L = ½ × 0.4583 × 235² × 125 × 0.396 = 627.6 kN
D = ½ ρ V² S C_D , C_D = C_D0 + C_L²/(π e AR) = 0.0200 + 0.0061
W = m × g = 64,000 × 9.807 = 627.6 kN
T = D · L = W
ROC = (T − D) × V / W = 45.5 kN × 235 / 627.6 kN
Moments are taken about the CG. Positive is nose-up.
M = F × d ; static margin = x_NP − x_CG = 17.0 % MAC
With the CG ahead of the neutral point, an increase in angle of attack produces extra lift behind the CG, generating a nose-down moment that opposes the disturbance — positive static stability. Moving the CG aft reduces that restoring moment and the tail download needed for trim, which reduces trim drag but erodes stability.
In steady flight the lift required is fixed by W cos γ — the wing achieves it with a different C_L at each speed.
Induced drag falls with V², parasite drag rises with V². Their sum is minimum at V_MD, the best L/D speed.
The vertical gap between the curves is excess thrust. It closes at maximum level-flight speed and is greatest around the best angle-of-climb speed.
Excess power divided by weight is the rate of climb, so the widest power gap gives the best ROC speed.
Linear up to the critical angle of attack, then the flow separates and C_L breaks down. Slats extend the usable range; flaps shift the whole curve up.
Parabolic polar C_D = 0.0200 + C_L²/(π × 0.80 × 10.29). The tangent from the origin touches at best L/D, currently 15.2.
This visualization uses simplified aerodynamic relationships for educational purposes. Actual aircraft performance depends on aircraft-specific aerodynamic data, engine performance, atmospheric conditions, compressibility effects, configuration, and flight manual limitations. Never use these figures for real flight planning.