The total mass of the aircraft can be said to act through one point called Centre of Gravity (CG). The CG is along the longitudinal axis of the aircraft and can be described as one point where the sum of the weight moments acting on the aircraft is zero.

The fuel is fed from the tanks in the correct sequence to maintain wing bending relief and CG position. The CG position does change as fuel is burnt off, but within defined limits. If it is burnt from a tank aft of the aircraft's CG, then the CG will move forward. Conversely, if the fuel is burnt from a tank positioned forward of the CG, then it will move aft.

Passenger and crew movements along the fuselage during flight are inevitable, but allowed for, resulting in CG changes. Small trim changes may be required to compensate for this movement.

On most large aircraft, the main gear retracts sideways and creates no change to CG position. The nose gear can retract either forwards or backwards. As it does so, it will cause the CG to move a small amount in that direction, but is usually considered to be negligible.

Any change of the tailplane (horizontal stabiliser) incidence angle does not have any effect to the CG position.