Rising Temperatures Affect Aircraft Takeoffs
Rising temperatures make it harder for aircraft to take off in coming decades, says a new study.
The study from Climatic Change concludes, during the hottest parts of the day, 10 to 30 percent of fully loaded planes may have to remove fuel, cargo or passengers, or else wait for cooler hours to fly.
“Our results suggest that weight restriction may impose a non-trivial cost on airline and impact aviation operations around the world,” said lead author Ethan Coffel, a Columbia University PhD. student.
The study goes on to say that, as air warms, it thins out, and its density declines. In thinner air, airplane wings generate less lift as a plane races along a runway. Thus, runway length and other factors mean that a packed plane may be unable to take off safely. In the event of high temperatures, some weight must be dumped, or the flight will be delayed or canceled
As an example, in late June, American Airlines canceled more than 40 flights out of Phoenix, Arizona, when daytime highs of nearly 120 degrees made it too hot for smaller regional jets to take off. The study went on to predict that heat waves will become more prevalent.
“This points to the unexplored risks of changing climate on aviation,” said coauthor Radley Horton, a climatologist at Columbia University’s Lamont-Doherty Earth Observatory. “As the world gets more connected and aviation grows, there may be substantial potential for cascading effects, economic and otherwise.”
Most studies so far have focused on how aviation may affect global warming, not vice versa. But a handful of studies have warned that warming climate may increase dangerous turbulence along major air routes, and head winds that could lengthen travel times. Furthermore, Mr. Coffel and Mr. Horton may be the only ones so far to look at the potential impacts to aircraft schedules and safety.
In 2015, they published another report, predicting up to four times more future temperature-related takeoff problems for the common Boeing 737-800 at airports such as Phoenix, Denver, New York’s LaGuardia and Washington’s Ronald Reagan, as well as 15 of the other busiest airports in the United States, Europe, the Mideast, China and south Asia.
The authors estimate that if globe-warming emissions continue unabated, aircraft fuel capacities and payload weights will have to be reduced by up to 4 percent on the hottest days for some aircraft. For an average aircraft operating today, a 4 percent weight reduction would mean roughly 12 or 13 fewer passengers on an average 160-seat craft. This does not count the major logistical and economic effects of delays and cancelations that can instantly ripple from one air hub to another, said Horton.
Some aircraft with lower temperature tolerances will fare worse than others, and certain airports—those with shorter runways, in hotter parts of the world or at higher elevations, where the air is already thinner--will suffer more. For instance, facing LaGuardia’s short runways, a Boeing 737-800 may have to offload weight half the time during the hottest days. Dubai, in the United Arab Emirates, might be worse; its runways are long, but its temperatures are already very high. Airports probably less affected because they are in temperate regions and have long runways include New York’s JFK, London Heathrow and Paris’s Charles de Gaulle.
Mr. Horton said that some effects could be mitigated with new engine or body designs, or expanded runways. But modifications would come at a cost, as aircraft are already highly engineered for efficiency; and expanded runways in densely packed cities such as New York are not an option. “The sooner climate can be incorporated into mid- and long-range plans, the more effective adaptation efforts can be,” said Mr. Coffel.