What is the minimum ambient temperature approved for takeoff?

• A. -60°C
• B. -40°C
• C. -20°C
• D. -5°C

Answer: (B)

The main idea here is the certified minimum ambient temperature for takeoff, which is part of the aircraft’s environmental operating limits. Airplanes are certified to operate safely only within a defined range of outside temperatures, and the minimum takeoff temperature is the lowest air temperature at which the manufacturer guarantees that engines, systems, and performance will meet safety and certification standards during takeoff. At very cold temps, things like fuel and oil viscosity, battery and hydraulic performance, and ice protection behavior can change, so the limit ensures takeoff safety under those conditions. That’s why -40°C is the correct choice—it's the standard lower bound for many aircraft. Lower values like -60°C would typically lie outside the usual certified envelope for standard transport airplanes, while -20°C or -5°C are warmer than the required minimum.