US aviation industry in crisis due to severe heat

High temperatures in many regions are forcing US airlines to adjust operations in the hardest-hit cities, choosing between cutting fuel or baggage, and in some cases even passengers, to keep planes flying.

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High temperatures in many areas are forcing US airlines to adjust operations in the hardest-hit cities. (Source: American Airlines)

Allegiant Airlines, a unit of Allegiant Travel, said it would suspend flights if there was a threat to the safety or comfort of passengers. The announcement came as temperatures in the U.S. Southwest continued to hit record highs.

In Las Vegas, where Allegiant is headquartered, an excessive heat advisory has been extended through Sunday (local time). Temperatures there have topped 100 degrees Fahrenheit since June 30, according to data from the National Weather Service.

Higher temperatures make the air less dense, reducing engine efficiency and the lift generated at a given speed. This results in a lower takeoff weight and a longer takeoff distance to generate enough lift. As a result, airlines have to reduce the weight on their planes.

Aircraft are connected to external cooling units when they are at the gate, but extreme temperatures can hamper their ability to function. After the plane leaves the gate, in most cases the air drawn into the engines is cooled and then circulated into the cabin.

American Airlines said it is taking extra steps to ensure the air on the jet bridge connecting to the plane is cooled. CEO Robert Isom recently said the airline has also performed early maintenance on the auxiliary components that run the systems on the plane when the engines are off.

Delta, American and United Airlines said airport staff, baggage handlers and others working outdoors will get more frequent breaks, extra water and cooling towels, and access to shaded areas or air conditioning.

The heat wave has been going on for weeks and is expected to continue through the weekend across much of the Southwest. Aside from Las Vegas, where the high temperature soared to 111 degrees Fahrenheit (47 degrees Celsius) on July 16, the Phoenix area recorded temperatures above 111 degrees Fahrenheit (48 degrees Celsius) on July 19-20 and has been above 100 degrees Fahrenheit (37 degrees Celsius) since June 14.

On July 17, some Delta Air Lines passengers voluntarily deplaned a flight from Las Vegas to Atlanta after heat-related weight issues caused delays. In 2017, extreme summer temperatures forced airlines to cancel some flights in Phoenix, mostly those using smaller jets and older aircraft.

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