40 flights cancelled due to excessive heatwave

Forty flights have been cancelled in Phoenix, Arizona,  as it is too hot for the planes to fly. The weather forecast for the US city is predicted at 49ᵒC on Tuesday, which is higher than the operating temperature of some planes. American Airlines announced it was cancelling dozens of flights scheduled to take off from Sky Harbour airport during the hottest part of the day.

The last highest temperature ever recorded in Phoenix was  50ᵒC on 26  June 1990.

The scientific reason for cancelling flights  at higher temperature, are as the air has a lower density  and is thinner and reduces how much lift is generated on an aircraft’s wings – a basic principle in aeronautics and aircraft’s engines is forced to generate more thrust to get airborne and also limits the payload or the fuel-carrying capacity.

However Boeing 747s and Airbus models can operate at higher temperature and have not been affected by the heat in Phoenix. The Death Valley National Parks Service have already issued a warning to visitors banning hiking after 10am and advised them to  travel only if they are well prepared to survive.