At the service ceiling, what is the expected margin to stall in terms of load factor?

At the service ceiling, the performance of an aircraft is such that it can no longer maintain a standard climb rate. The load factor at this altitude influences how the aircraft can perform maneuvers. Generally, the expected margin to stall at the service ceiling is around 1.5g. This means that at the service ceiling, when operating near the limits of performance, the aircraft can still withstand a load factor of 1.5 times its weight before reaching a stall condition.

This margin accounts for the reduced power available at higher altitudes, which impacts the ability of the aircraft to generate enough lift. In this context, as the load factor increases during maneuvers, the stall speed also increases. Therefore, a margin of 1.5g is an essential threshold to ensure safe operation, providing a buffer against stalling in normal flight conditions.