Extreme heat events are increasing in frequency and duration posing another challenge to civil aviation.
1. Flights cancelled
A Delta Air Lines Flight due to depart from Las Vegas to Atlanta was canceled on July 17 before its departure because the inside of the plane was too hot and people fell ill. Passengers were stuck on the plane for three hours while temperatures outside were around 43°C. Paramedics wheeled out at least three people who passed out from heat exhaustion, according to media reports.
2. Longer runways and inconvenient hours
Usually, aircraft engines rely on the intake of dense air for efficient combustion and thrust generation. In order to deal with extreme weather disrupting air travel, longer runways for takeoff may be part of the solution. Airports in hot regions, in particular, might need longer runways to accommodate this.
London’s City Airport has a runway that’s just under 5,000 feet in length. During a heatwave in 2018, more than a dozen flights were forced to leave passengers on the ground in order to take off safely. In 2017, dozens of flights were canceled entirely over a few days at Phoenix’s Sky Harbor International airport, as temperatures reached 48.8°C, which is above the maximum operating temperature for many passenger planes.
Another option when dealing with more frequent and hotter heat waves is to move long-haul summer flights to early morning or late evening when it’s cooler. But that can create havoc with scheduling and require passengers to fly at inconvenient times.
3. Hot air affects aircraft performance
Hot air is less dense than cold air, and this can affect aircraft performance since engines might produce less power, leading to longer takeoff distances and reduced climb rates. The reduced engine performance and thinner air can lead to a need for higher speeds to achieve the necessary lift for takeoff.
“The basic challenge facing any aircraft as it takes off is that planes are just very heavy, and gravity wants to keep them on the ground,” Paul Williams, a professor of atmospheric science at the University of Reading in the UK told CNN. “In order to overcome gravity, they need to generate lift, which is the atmosphere pushing the plane up. Lift depends on several factors, but one of the most important is the temperature of the air — and as the air warms up it expands, so the number of molecules available to push the plane up is reduced,” Williams explained.