What is the time until unconsciousness (TUC) at an altitude of 28,000 feet?

At an altitude of 28,000 feet, the time until unconsciousness (TUC) is typically around 1 minute. This estimation is based on the physiological effects of hypoxia, which occurs when the body receives inadequate oxygen. As altitude increases, the partial pressure of oxygen decreases, leading to a more rapid onset of hypoxia.

At 28,000 feet, individuals may experience symptoms of hypoxia such as impaired cognitive function, muscle coordination, and awareness, often leading to unconsciousness within a minute if supplemental oxygen is not provided. This rapid decline in usable oxygen is a crucial consideration for those operating at high altitudes, as it underscores the need for appropriate precautions, such as supplemental oxygen systems or pressure suits during flight operations.

The other time frames listed do not align with the physiological responses expected at that altitude. For example, significantly longer TUC values are associated with lower altitudes where adequate levels of oxygen are still available for normal physiological function. Understanding the impacts of altitude on human physiology is essential for aviation safety and performance.