The Delta pilot who dumped jet fuel on schoolkids told air traffic control moments before that he wasn't going to do it

• A Delta flight dumped tons of jet fuel over nearby schools during an emergency landing Tuesday in Los Angeles. 67 people, including children, needed treatment after exposure.
• New transcripts show that the pilot was asked whether he needed to dump fuel on his way back. He replied "negative" - but the fuel was dumped anyway.
• Pilots are only supposed to duMp fuel over unpopulated areas, or high enough up that it evaporates before getting to the ground. The FAA is investigating why this didn't happen.
• Visit Business Insider's homepage for more stories.

A Delta pilot who dumped jet fuel over elementary school kids in Los Angeles on Tuesday told air traffic control moments beforehand that he wasn't going to do it.

Radio transcripts of exchanges between Delta Air Lines flight 89 and controllers at Los Angeles International Airport (LAX) show the pilot being asked if he needed to dump fuel, to which he replied "negative."

In fact, the plane did dump fuel, which ended up dousing at least 67 people, including dozens of children, with fuel from the plane.

Those affected reported skin irritation and breathing problems, but none so serious as to require hospital treatment.

Flight 89 was meant to fly from LAX to Shanghai, China, but reported an engine problem shortly after take-off and decided to come back.

Fuel dumping is a normal emergency procedure when heavily-loaded planes need to land quickly. But Federal Aviation Administration (FAA) guidelines say only to do it away from populated areas, and high up enough that the fuel can evaporate.

Recordings obtained by the Associated Press show discussions between the pilot and air traffic control at LAX.

The exchange begins with the controller asking if the plane wanted to come straight back, or circle over the Pacific Ocean to burn fuel. (Flying in circles is a way to lighten a plane for landing without fuel dumping.)

It continues:

Pilot: We're going to go ahead... We've got it back under control. ... We're not critical.

Controller: OK, so you don't need to hold or dump fuel or anything like that?

Pilot: Ah, negative.

It is not clear why the plane then jettisoned its fuel anyway. The FAA is investigating what happened.

Delta told Business Insider that the investigation into the exchange is still ongoing.

In an earlier statement it said the plane turned back due to an "engine issue" that required an immediate return. It did not elaborate on why the fuel was dumped where it was.

Delta on Tuesday sent overnight cleaning crews to the schools hit by the jet fuel.

The airline held a joint press conference with the Superintendent of the Los Angeles Unified School District and the LA County Health Department on Wednesday, where officials said that they do not expect any long-term consequences for those affected.

David Slotnick contributed reporting to this article.