Climate change is making it harder for planes to take off | Tech US News


(CNN) – The increase in temperatures on our planet is making it more difficult for planes to take off at certain airports, which poses yet another challenge for civil aviation. And as heat waves become more frequent, the problem could spread to more flights, forcing airlines to ground passengers.

“The basic challenge any airplane faces when it takes off is that airplanes are very heavy and gravity wants to keep them on the ground,” says Paul Williams, professor of atmospheric science at the University of Reading in the UK. “To overcome gravity, they need to generate lift, which is the atmosphere that pushes the plane up.

“Lift depends on several factors, but one of the most important is air temperature, and as air warms, it expands, so the number of molecules available to push the plane up is reduced.

Airplanes get 1% less lift for every 5.4 degrees Fahrenheit (3 degrees Celsius) of temperature increase, Williams said.

“That’s why extreme heat makes it difficult for planes to take off, and in some really extreme conditions it can become completely impossible,” he said.

The problem particularly affects high-altitude airports, where the air is already naturally thinner, and with short runways, which leave the plane less room to accelerate. According to Williams, if an airplane requires 6,500 feet of runway at 68 degrees Fahrenheit (20 degrees Celsius), it will need 8,200 feet at 104 degrees (40 degrees Celsius).

“Global shutdown”

Williams and his team investigated historical data from 10 airports in Greece, all characterized by high summer temperatures and short runways. They found a warming of 1.35 degrees Fahrenheit (0.75 Celsius) per decade since the 1970s.

“We also found a decrease in headwind along the track, by 2.3 knots per decade,” Williams said. “Headwinds are beneficial for takeoffs, and there’s some evidence that climate change is causing what’s called ‘global attention,’ so the winds seem to be decreasing.”

The team then put those temperatures and headwinds into an aircraft takeoff performance calculator for a variety of different aircraft types, including the Airbus A320, one of the world’s most popular aircraft.

An Aegean Airlines Airbus A320 on the tarmac at Athens International Airport in October 2022.

An Aegean Airlines Airbus A320 on the runway at Athens International Airport in October 2022.

Daniel Slim/AFP/Getty Images

“What we found was that the maximum take-off weight was reduced by 280 pounds (127 kilograms) each year, which is roughly equivalent to the weight of a passenger plus their bag, meaning one less passenger each year that can be carried” , Williams Williams. he says

From its introduction in 1988 to 2017, the A320 would have reduced its maximum take-off weight by more than 8,000 pounds at the national airport on the island of Chios, the study’s main airport, which has a runway length of just under 5,000 feet (1,500 meters). .

London City Airport, in the UK capital’s financial district, also has a runway just under 5,000 feet long. During a heat wave in 2018, more than a dozen flights were forced to ground passengers in order to safely take off. Up to 20 people crashed in one flight.
In 2017, dozens of flights were canceled entirely over the course of a few days at Phoenix’s Sky Harbor International Airport as temperatures reached 120 degrees Fahrenheit (48.8 degrees Celsius), which is above the maximum operating temperature for many aircraft of passengers
Phoenix Sky Harbor International Airport in June 2017.

Phoenix Sky Harbor International Airport in June 2017.

Matt York/AP

A Columbia University study predicts that by 2050, a typical narrow-body aircraft such as the Boeing 737 will experience a 50% to 200% increase in weight restrictions during the summer months at four major US airports: La Guardia, Reagan National Airport and Denver International. and Sky Harbor.

Possible solutions

Fortunately, airlines are not helpless in the face of the problem.

“There are a lot of solutions on the table,” says Williams. “One would be to schedule departures away from the hottest part of the day, with more early morning and late afternoon departures, which is a tactic already used in hot areas like the Middle East.”

Lighter aircraft are also less affected by the problem, so this could accelerate the adoption of composite materials such as carbon fiber for airframes, according to Williams.

Meanwhile, manufacturers such as Boeing already offer a “hot and high” option on some of their planes, for airlines that plan to use them extensively at high-altitude, high-temperature airports. The option offers additional thrust and larger airfoils to compensate for the loss of lift, with no change in range or passenger capacity.

Of course, a more drastic approach would be to lengthen the runways, although this may not be possible at all airports.

In some cases, where none of these solutions are applicable, passengers will simply have to give up their seats. But, says Williams, this will remain a niche problem for the foreseeable future, at least: “People being kicked out of planes because it’s too hot is rare and will remain rare. Most planes never reach their maximum weight of take off, so this will happen. in marginal cases, mainly airports with short runways, at high altitude and in the summer,” he says.

However, the long-term future may be more difficult, he adds: “I don’t think it’s going to be a big headache for the industry, but I think there’s strong evidence that it’s going to get worse.”

(Top image: High temperatures and heat waves distort the image of a passenger jet as it takes off at Ronald Reagan National Airport in Washington, DC in August 2002. Credit: PAUL J. RICHARDS/AFP via Getty Images)


Source link

Please disable your adblocker or whitelist this site!