What happens when the center of gravity (CG) is located aft?

When the center of gravity (CG) is located aft in an aircraft, it influences the aircraft's stability and control characteristics. An aft CG tends to create a pitch-up tendency. This occurs because the moment arm for the lift generated by the wings increases, causing the nose of the aircraft to want to rise.

With an aft CG, the aircraft can become less stable in pitch, as there is a reduced nose-down pitching moment generated by the horizontal stabilizer. This makes it easier for the aircraft to ascend or enter a climb but can also lead to difficulties in handling, especially during maneuvers or in turbulent conditions, as it may require constant attention to maintain level flight.

The other options, while related to stability and control, do not accurately reflect the effects of an aft CG. For instance, pitch down tendency is typically associated with a forward CG, and improvements in roll or yaw stability would generally not be characteristic of an aft CG position either.