What is the minimum air temperature in flight?

What is the minimum air temperature in flight?

• A. -70C
• B. -40C
• C. -80C
• D. -60C

Answer: (A)

Outside air temperature has a certified lower limit for safe flight. This is the coldest ambient temperature the aircraft and its systems are designed to operate in without risking performance or safety. In this context, that lower limit is -70°C, so the aircraft can be flown at or above -70°C, but not in colder air. Warmer temperatures, like -60°C or -40°C, are within the approved range, while colder air, such as -80°C, would be outside the certified envelope. The limit is set during certification based on how the aircraft’s systems perform under extreme cold.

Outside air temperature has a certified lower limit for safe flight. This is the coldest ambient temperature the aircraft and its systems are designed to operate in without risking performance or safety. In this context, that lower limit is -70°C, so the aircraft can be flown at or above -70°C, but not in colder air. Warmer temperatures, like -60°C or -40°C, are within the approved range, while colder air, such as -80°C, would be outside the certified envelope. The limit is set during certification based on how the aircraft’s systems perform under extreme cold.