Hover or tab onto CG, CP or the thrust line for an explanation.
Flight deck controls
Thrust levers
85% N1
Flaps
Landing gear
▼▼▼▼▼▼UP
MCDU · Fuel
INIT FUEL PRED
BLOCK9.0
ZFW55.0
GW64.0
Altitude · speed
SPEED kt
ALT ft
PERF CRZ
FLFL350
MACH0.779
GW64.0 t
N185 %
MAX FLFL365
SPD MARGIN34 kt
CLIMBING +210 ft/min
COFFIN CORNER
Aircraft state
Flight phaseCRUISE
Altitude35,000 ftρ 0.3796 kg/m³ · σ 0.310
Airspeed250 kt EAS449 kt TAS
Mach number0.779
Dynamic pressure q10.13 kPa
Angle of attack α3.4°stall α 15.5° · margin 12.1°
Pitch attitude θ3.7°θ = α + γ
Flight path angle γ0.3°
Load factor n1.000 gn = cos γ in steady flight
Stall speed200 kt EASV/VS 1.25
Forces
Lift L627.6 kNC_L 0.497 of C_Lmax 0.78
Weight W627.6 kN64,000 kg
Thrust available41.9 kN
Thrust required41.9 kND + W sin γ
Total drag D38.9 kNC_D 0.0308
— parasite26.8 kNC_D0 0.0213
— induced12.1 kNC_Di 0.0096
W sin γ along path3.0 kN
L = ½ ρ V² S C_L = ½ × 0.3796 × 231² × 125 × 0.497 = 627.6 kN
D = ½ ρ V² S C_D , C_D = C_D0 + C_L²/(π e AR) = 0.0213 + 0.0096
W = m × g = 64,000 × 9.807 = 627.6 kN
T = D · L = W
Performance
Excess thrust3.0 kN
Excess power0.68 MW
Rate of climb215 fpmsustainable γ 0.3°
Climb gradient0.5 %
Lift/drag ratio16.13
Fuel flow3,332 kg/hspecific range 0.135 NM/kg
ROC = (T − D) × V / W = 3.0 kN × 231 / 627.6 kN
Stability and moments
Moments are taken about the CG. Positive is nose-up.
CG25.0 % MAC
CP30.0 % MAC
Aerodynamic centre25.0 % MAC
Neutral point42.0 % MAC
Static margin17.0 % MAC
Wing lift moment-131.9 kN·mnose-down
Thrust moment37.7 kN·mnose-up
Tail force6.6 kNupload
Tail moment94.2 kN·m
Net moment (trimmed)0.00 kN·m
Longitudinal stabilitySTABLE
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.
Model assumptions
Steady, symmetric flight: no acceleration along or normal to the flight path.
Parabolic drag polar plus transonic wave drag above M 0.69; buffet C_L falls with Mach (coffin corner).
Linear lift curve up to the critical angle of attack.
Thrust ∝ N1 (steep curve) × σ^0.87, tuned so 85 % N1 holds FL380 light and ~FL320 with 18 t fuel.
ISA troposphere and stratosphere; density from pressure altitude and ISA deviation.
Neutral point fixed at 42 % MAC, aerodynamic centre at 25 % MAC, tail arm 3.4 MAC.
Real-time performance graphs
Lift vs airspeed
Lift requiredWeight
In steady flight the lift required is fixed by W cos γ — the wing achieves it with a different C_L at each speed.
Drag vs airspeed
ParasiteInducedTotal
Induced drag falls with V², parasite drag rises with V². Their sum is minimum at V_MD, the best L/D speed.
Thrust required vs available
RequiredAvailable
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.
Power required vs available
RequiredAvailable
Excess power divided by weight is the rate of climb, so the widest power gap gives the best ROC speed.
Lift coefficient vs angle of attack
C_L
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.
Drag polar
C_D vs C_L
Parabolic polar C_D = 0.0213 + C_L²/(π × 0.80 × 10.29). The tangent from the origin touches at best L/D, currently 16.1.
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.