What is the maximum time allowed for negative G operation?

The maximum time allowed for negative G operation is indeed 60 seconds. This limit is established primarily to mitigate the physiological effects that sustained negative G forces can have on the body. When an aircraft experiences negative G forces, it can lead to a condition known as "negative G-induced loss of consciousness" (GLOC). This phenomenon occurs due to blood pooling in the upper body and brain, depriving these areas of sufficient blood flow.

The 60-second limit is based on comprehensive research and operational studies related to human tolerance to negative G environments. After this duration, the risk of incapacitation increases significantly, as the body may not effectively cope with prolonged exposure to these forces. It's crucial for pilots and operational personnel to be aware of these limits to maintain safety and performance during flight maneuvers that involve negative G's.