Aviation Terms->Center of Gravity (CG)
The point at which the mass of the aircraft is balanced. This changes depending on the loading of the aircraft: fuel, passengers, luggage, etc. Different aircraft have CG limits specified by their manufacturer. If the CG of the aircraft in its current configuration is outside of the specified limits, the aircraft may be unsafe to fly. For example, if the CG is behind the aft (rear) CG limit, the aircraft will tend to stall.