American Airlines on Monday urged its pilots to do everything possible to save fuel, warning that a supply crunch in the United States is challenging company operations.

"Use all available fuel savings strategies when possible," Managing Director of Flight Operations John Dudley said in a memo to pilots. "Every gallon of jet fuel saved is helpful."

Factors behind the supply crunch include shortages of the fuel itself as well as trucks to transport it and drivers, Dudley said.

"These challenges are not only impacting airports and airlines but also the efforts to fight the large forest fires on the West Coast," the memo said.

The fuel crunch is the latest problem facing US carriers, which are experiencing a vaccine-fueled surge in travel demand after a sharp downturn last year during the worst of the Covid-19 pandemic.

American Airlines told pilots to conserve fuel in light of a supply crunch American Airlines told pilots to conserve fuel in light of a supply crunch Photo: AFP / CHANDAN KHANNA

The fuel shortages were found initially in the western United States, but "are now being reported at American stations across the country," Dudley said, adding that fuel delivery delays were expected through mid-August.

Dennis Tajer, a spokesman for the Allied Pilots Association (APA), said he expects planes to fly with more fuel than is needed to complete their journey when they travel from cities where fuel is more abundant into cities where supplies are tight.

Because extra fuel adds weight, planes may need to leave some seats empty, he told AFP, adding that "safety is the most important thing."

Besides working to conserve fuel, Dudley urged pilots to contact American Airlines dispatchers early "if it is necessary to land enroute" and noted that taking on extra fuel "will lead to a heavier aircraft when landing."

A memo from APA to union members restated many of the same points, adding, "these new challenges are manageable, but it's important to be proactive and work closely with the load agents and dispatchers."