Definition
The aerodynamic principle that the airspeed at which an aircraft will stall rises whenever load factor exceeds 1G, such as during turns, pull-ups, or recovery from dives. The increase is proportional to the square root of the load factor: at 2Gs, stalling speed is approximately 1.4 times the wings-level (1G) stall speed; at 4Gs, it doubles.
Plain English
The faster the wings have to work to support more than the airplane's normal weight — like in a steep turn — the higher the speed at which the airplane will stop flying and stall. Pull harder on the controls and the airplane will stall at a higher speed than it would in level flight.
Context Anchor
Seen in load factor discussions, especially when learning why steep turns and abrupt control inputs raise the speed at which a stall can occur.
Derivation
Stall comes from an older meaning of stopping or coming to a standstill. In aviation, it does not mean the engine stops; it means the wing has stopped producing smooth, effective lift because it has been tilted too much into the airflow. Increases simply means the speed goes up.
Why Pilots Care
Failing to account for the rise means the aircraft can stall at an airspeed that normally feels safe, reducing the margin for maneuvering.
Grounding Statement
Anytime the wings are asked to lift more than the airplane's normal weight, the speed needed to keep flying goes up.
Intuition Check
Do not assume stall speed is one fixed number for all flight conditions. If the wings are carrying extra load, the stalling speed increases.
Example Sentence 1
In a 60-degree banked level turn the load factor is 2Gs, so stalling speed increases by about 40 percent over the wings-level value.
Example Sentence 2
Recovering from a steep descent, the pilot eases the back pressure so the stalling speed does not rise above the current airspeed.