Extreme temperatures in parts of the US and around the world are forcing airlines to reduce fuel loads, shed passengers or baggage, or wait for daytime temperatures to drop in the evenings, to fly some aircraft.
High temperatures reduce the performance of engines and the lift airplanes’ wings are able to produce, which is leading Las Vegas-based Allegiant Airlines to warn that they will delay flights if there is a threat to passenger safety.
Earlier this month, several Delta passengers voluntarily got off a flight from Las Vegas to Atlanta after aircraft weight issues in the heat caused delays, Bloomberg reported.
“Additional protocols have been put in place to address the operational impacts extreme heat has on aircraft, including loading less fuel to account for weight and balance and schedule refueling along the route when needed,” Delta said in a statement.
Last week, a Delta flight from Las Vegas to Atlanta sat on the tarmac for four hours in 115F (46C) heat, without air conditioning, causing some passengers to experience heat-related sickness. The US transportation secretary, Pete Buttigieg, called the incident “shocking”.
American Airlines has also responded to the issue, saying it is taking extra steps to make sure it has cooled air on jet bridges hooked to planes and to perform early maintenance on auxiliary power units, the smaller engines that give power when larger engines are shut down.
“Though we’ve had a very small number of diversions and delays related to high temperatures, the plan we have in place has allowed us to avoid significant impact,” an American Airlines spokeswoman told Bloomberg.
The complications that high temperatures can cause a plane’s performance are due in part to some flight manuals recommending aircraft do not go above 120F. “When exposed to extreme heat exceeding its maximum operating temperature, passengers aboard the airplane could be at risk,” according to Monroe Aerospace.
Last week, park service officials in Death Valley, where temperatures can reach 130F, warned hikers that rescue helicopters would not be able to fly to their aid during daytime.
A heat dome over the US south-west has caused temperatures in Las Vegas to soar to 116F on 16 July and Phoenix to hit 119F. Extreme temperatures in Phoenix in 2017 also forced cancellation of some 60 flights, primarily by smaller regional jets and older aircraft, over the course of three days because safety calculations were not calibrated for 120F temperatures.
Industry expert Robert Mann told the Guardian last year that flights “have to wait until the sun goes down, the temperature drops, and they can take off”.
Mann added: “As temperatures increase, there are going to be more occasions, at more places, where certain flights are going to have to take payload limitations or stop en route because they had to short-load the fuel.”
