At what altitude does the time of useful consciousness drop to 13 to 30 seconds?

At what altitude does the time of useful consciousness drop to 13 to 30 seconds?

• A. 30,000 feet
• B. 25,000 feet
• C. 40,000 feet
• D. 45,000 feet

Answer: (C)

The correct altitude at which the time of useful consciousness drops to 13 to 30 seconds is 40,000 feet. At this height, the partial pressure of oxygen available to the body decreases significantly due to the thinner atmosphere, leading to hypoxia, which is a deficiency in the amount of oxygen reaching the tissues. At 40,000 feet, physiological responses are markedly affected, and an individual would experience rapid loss of cognitive and motor functions if not supplied with supplemental oxygen. This is why it is critical for pilots and crew to use supplemental oxygen above this altitude. The time of useful consciousness refers to the duration within which a person can effectively function before severe impairment sets in due to lack of oxygen. The other altitudes listed represent different thresholds for the time of useful consciousness. For instance, at 30,000 feet, the time of useful consciousness would be longer than at 40,000 feet, while at 25,000 feet, individuals could still maintain a higher level of functionality. Above 40,000 feet, this time decreases even further, and the critical nature of oxygen availability intensifies, necessitating immediate action to prevent incapacitation.

The correct altitude at which the time of useful consciousness drops to 13 to 30 seconds is 40,000 feet. At this height, the partial pressure of oxygen available to the body decreases significantly due to the thinner atmosphere, leading to hypoxia, which is a deficiency in the amount of oxygen reaching the tissues.

At 40,000 feet, physiological responses are markedly affected, and an individual would experience rapid loss of cognitive and motor functions if not supplied with supplemental oxygen. This is why it is critical for pilots and crew to use supplemental oxygen above this altitude. The time of useful consciousness refers to the duration within which a person can effectively function before severe impairment sets in due to lack of oxygen.

The other altitudes listed represent different thresholds for the time of useful consciousness. For instance, at 30,000 feet, the time of useful consciousness would be longer than at 40,000 feet, while at 25,000 feet, individuals could still maintain a higher level of functionality. Above 40,000 feet, this time decreases even further, and the critical nature of oxygen availability intensifies, necessitating immediate action to prevent incapacitation.