April 23, 2019 Alan Walker
When frigid cold weather occurs, most headlines suggest that below freezing temperatures result in grounded flights. You might be surprised to hear that aircraft actually run more efficiently in relatively cold weather—here’s why.
Most commercial aircraft are designed to withstand varying temperature changes in their flight cycle. At 35,000 feet in the air, the temperature can range anywhere from -40 to -70 ?. Jet fuel freezes at about -40 ?, but redundancies on an aircraft are designed to keep all components running smoothly. As long as the aircraft systems are kept heated at minimum temperature specifications, they have no problem operating in extremely cold weather.
An aircraft engine system is also more efficient in lower temperatures. This is because the air is denser and less humid. There are more oxygen molecules readily available in a given space than during warm or hot weather. The engine is able to utilize a larger mass of air and fuel mixture, giving it more horsepower, shorter and faster take offs, and better overall performance. On hotter days, less fuel can be burned because the air is less dense and therefore not as readily available for use, therefore causing the engine to burn inefficiently and potentially cause unnecessary engine wear and tear.
Instead, the cause of flight cancellations during cold weather is often due to the presence of ice or snow on the aircraft, and at the airport itself. Ice and snow can change the pattern of airflow over the surface of an airplane, and this is especially harmful to the aerodynamics of an aircraft wing. This causes longer take off rolls and a higher stall speed in flight. Lastly, the methods needed per aircraft during icing conditions are time consuming and expensive.
For airports, cold weather can be extremely detrimental to daily operations. Flight crew and maintenance workers can only stay outside in low temperatures for a short amount of time. While the aircraft is equipped to keep itself warm, aircraft maintenance equipment is not, and can freeze easily. Ice on the tarmac results in dangerous conditions for both the airport staff and for standard takeoff and landings.
Overall, it’s not cold temperatures that cause flight cancellations. The associated dangers of icing conditions and the necessary changes in airport operations are the main contributors flight complications faced during cold weather.