Delta Airlines audio reveals pilots told controllers no fuel dump was needed before dropping it on primary school

A Delta Airlines flight that dumped fuel on several Los Angeles schools before making an emergency landing did not inform air traffic controllers of its intention, according to aviation authorities and audio posted on various air traffic control websites.

Delta Flight 89, which turned back for an emergency landing at Los Angeles International Airport after departing for Shanghai on Wednesday (NZT), dumped fuel on the playgrounds of at least four schools in its flight path, causing minor injuries to more than 40 children and adults on the ground.

"A review of yesterday's air traffic control communications shows the Delta Flight 89 crew did not tell air traffic control that they needed to dump fuel," the Federal Aviation Administration said.

"In this emergency situation, the fuel-dumping procedure did not occur at an optimal altitude that would have allowed the fuel to atomise properly."

Before making emergency landings, planes often dump fuel to reduce their weight for safety reasons.

The FAA said in a statement that air crews will typically notify air traffic control of an emergency and indicate the need to dump fuel, with controllers then directing the crew to an appropriate fuel-dumping area.

In the air traffic control recording, the controller can be heard asking the Delta pilot about fuel.

"OK, so you don't need to hold to dump fuel or anything like that?" the control asked. 

The pilot responded, "Negative."

The agency said it is continuing to investigate the circumstances behind the incident.

Delta said on Tuesday it shares "concerns regarding reported minor injuries to adults and children at a school in the area" and said the fuel was dumped to reach a safe landing weight.

It said on its website that 13 airline cleaning crews worked with school crews "to clean all outside surfaces that students could come into contact with."