A Delta Air Lines jet that dumped fuel over several Los Angeles schools had not sought approval to do so, according to the US Federal Aviation Administration.
Fire crews treated 60 people Tuesday after Delta Flight 89 dumped fuel over a populated area that includes five elementary schools and a high school while returning to Los Angeles after an engine issue.
Minor injuries were reported among 20 children and 11 adults at one elementary school, although none required hospitalization.
Some people hit by the fuel were decontaminated with soap and water and witnesses reported rain that smelled like gasoline.
Pilots generally notify air traffic control of the need to dump fuel and are directed to an area where they can safely do so.
This typically involves designated unpopulated areas and the fuel is dumped at higher altitudes so it atomizes and disperses before it hits the ground.
In this case, according to a transcript from LiveATC.net and obtained by US media, the pilots were apparently asked by air traffic control whether they needed to hold or dump fuel and replied: “Uh, negative”.
The FAA, which is investigating the incident, confirmed in a statement there was no request to dump fuel and noted the procedure was not undertaken at an altitude that would have allowed it to atomize properly.
“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,” it said.
The Boeing 777-200 bound for Shanghai released the fuel to reach a safe landing weight that would avoid bursting tires and damaging the landing gear.
The Aviation Herald website reported the plane was climbing out of Los Angeles airport when it leveled off at 8000ft.
The crew reported a right engine compressor stall and said they needed to return to Los Angeles.
They subsequently reported they had brought the engine under control, the website said, and the plane landed safely about 25 minutes after departure.
Delta said it had contacted Los Angeles World Airports, the LA County Fire Department as well as community leaders “and shares concerns regarding reports of minor injuries to adults and children at schools in the area”.
The airline has sent cleaning crews to help clean outside surfaces at the affected schools.