Negative G operation, including inverted flight, is limited to how many seconds?

The limit for negative G operation, including inverted flight, is set at 60 seconds. This limitation is crucial for ensuring the safety and structural integrity of the aircraft, as prolonged exposure to negative G forces can lead to physiological effects on the pilot and potential mechanical stress on the aircraft.

During negative G operations, blood can pool away from the brain, which may lead to vision impairment and loss of consciousness. This is referred to as "greyout" or "blackout" conditions. It is essential to adhere to the 60-second limit to mitigate these risks and to prevent excessive wear and tear on the aircraft structure, which may be subjected to reverse aerodynamic forces in such flight conditions. The regulation of this time limit is established in the aircraft's operating limitations to ensure safe operations for pilots and the aircraft itself.