What is the time of useful consciousness at an altitude of 40,000 feet?

The time of useful consciousness at an altitude of 40,000 feet is approximately 18 seconds. This refers to the duration a person can remain functional and aware before being incapacitated due to hypoxia, which is a deficiency in the amount of oxygen reaching the tissues. At high altitudes, like 40,000 feet, atmospheric pressure decreases significantly, leading to lower oxygen availability.

Within this critical window of time, individuals can perform necessary actions, such as deploying oxygen masks or executing emergency procedures before losing consciousness. Knowing this time frame is crucial for pilots and crew members to ensure safety in emergencies where cabin pressure is lost. Understanding this concept highlights the importance of rapid response and preparedness in high-altitude aviation environments.