Definition
The rearmost (most aft) location along the aircraft's longitudinal axis at which the center of gravity is permitted to be located for safe flight, as established by the manufacturer and published in the aircraft's Type Certificate Data Sheet and Pilot's Operating Handbook. Loading the aircraft so that the CG falls behind this limit makes the aircraft less stable in pitch and can render it uncontrollable, particularly during stall recovery.
Plain English
The furthest-back point where the airplane's balance point is allowed to be. If the load is arranged so the balance point sits behind this point, the airplane becomes unsafe to fly.
Context Anchor
Seen during weight-and-balance calculations before flight, especially when passengers, baggage, or fuel loading could move the airplane’s balance point rearward.
Derivation
Aft' is an old nautical word meaning 'toward the rear of a vessel,' carried over into aviation from shipbuilding. 'CG' stands for 'center of gravity,' the single point where the aircraft's weight is considered to act. So 'aft CG limit' is simply the rear boundary for that balance point.
Why Pilots Care
Exceeding the aft CG limit reduces stability and can cause loss of pitch control, especially during takeoff, landing, or maneuvering.
Intuition Check
Aft does not just mean “somewhere behind you”; here it means toward the tail of the aircraft. Limit is not a suggestion or comfort zone; it is the approved boundary that the loaded aircraft must stay within.
Example Sentence 1
After loading the baggage compartment, the pilot recalculated the weight and balance and confirmed the CG was still forward of the aft CG limit.
Example Sentence 2
Placing extra baggage too far aft can move the CG past the aft CG limit and make the aircraft unstable in pitch.