Get Adobe Flash player

Aircraft Center of Gravity

Enter the variables at left using the same units for all entries.
    For an aircraft to be stable in pitch, its CG must be forward of the
    Neutral Point NP by a safety factor called the Static Margin, which
    is a percentage of the MAC (Mean Aerodynamic Chord).
    Static Margin should be between 5% and 15% for a good stability.

    Low Static Margin gives less static stability but greater elevator
    authority, whereas a higher Static Margin results in greater static
    stability but reduces elevator authority.
    Too much Static Margin makes the aircraft nose-heavy, which
    may result in elevator stall at take-off and/or landing.
    Whereas a low Static Margin makes the aircraft tail-heavy and
    susceptible to stall at low speed, e. g. during the landing approach.

    *Choose Low Stabiliser Efficiency if the tail is close to the wing's wake
    or behind a fat fuselage in disturbed flow.     

Wing Root Chord (A): 
Wing Tip Chord (B): 
Wing Sweep Distance (S): 
Wing Half Span (Y): 
Stabiliser Root Chord (AA): 
Stabiliser Tip Chord (BB): 
Stabiliser Sweep Distance (SS): 
Stabiliser Half Span (YY): 
Distance between both LE's (D): 
Stabiliser Efficiency*: 
Enter Static Margin, then
Mean Aerodynamic Chord MAC = 
Sweep Distance at MAC (C) = 
From Root Chord to MAC (d) = 
From Wing Root LE to AC = 
From Wing Root LE to NP = 
From Wing Root LE to CG = 
Wing Area = 
Stabiliser Area = 
Wing Aspect Ratio = 
Tail Volume Ratio,  Vbar =