At what altitude should the MOR handle be used if the automatic system fails?

The correct answer is that the MOR (Manual Override Rescue) handle should be used above 14,000 feet if the automatic system fails. This altitude is significant because it typically aligns with the operational limits of many aircraft regarding oxygen deployment and pilot safety protocols. In high-altitude scenarios, the risks associated with hypoxia—the deficiency of oxygen in the tissues—rise considerably, making the use of manual override systems critical in maintaining control of the aircraft.

Using the MOR handle at or below 14,000 feet may not be necessary as the automatic systems are reliable and can adequately manage the engine and propulsion under normal conditions. Therefore, the procedure is specifically designed to come into play when operating in more challenging environments or scenarios that extend beyond this altitude, ensuring that pilots can effectively manage situations where the automatic systems could potentially fail.