Recordings obtained by the Associated Press show discussions between the pilot and air traffic control at LAX.
At least 44 people at multiple elementary schools, including at least 20 children, were injured after an aircraft apparently dumped jet fuel before making an emergency landing at Los Angeles International Airport, officials said. However, pilots are encouraged not to dump fuel over populated areas, and to dump fuel at a high enough altitude that it dissipates before reaching the ground.
In case of a fire, he said, pilots will dump as much fuel as quickly as they can and land. "There is an ongoing investigation that was opened immediately after the flight landed back". The Boeing 777-200 landed safely after circling back over Los Angeles while dumping fuel to reach a safe landing weight, the airline said in a statement.
What was wrong with the plane's engine?
"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.
Scott Martin, a propulsion expert at Embry-Riddle Aeronautical University, said a stall puts more pressure on the compressor, and the Delta pilots might have assumed the worst - that they could soon face an engine failure that could cause parts to break off and become shrapnel capable of piercing the fuselage, fuel tanks or hydraulic lines.
The pilot described it as "not critical".
Controller: OK, so you don't need to hold or dump fuel or anything like that? "It's a pretty outrageous thing", said Ross Aimer, CEO of Aero Consulting Experts and a retired United Airlines pilot.
The controller asks whether he needs to return to the airport immediately or to "hold to burn fuel".
When a plane is forced to turn back after takeoff, the weight of a full load of fuel carries a risk of damaging the jet during landing.
"In this emergency situation, the fuel-dumping procedure did not occur at an optimal altitude that would have allowed the fuel to atomize properly", it added.
While details on the Delta incident are unclear, Soucie said one theory is pilots may have forgotten to dump the fuel until the final approach while doing a pre-landing checklist and discovered the weight of the plane was too heavy. And rather than go around the airport again to drop elsewhere, they might have chose to dump it over land.
"If you are in contact with an aircraft when it starts dumping fuel, inform other controllers and facilities which might be concerned".
According to the FAA, which is investigating Tuesday's incident, there are special fuel-dumping procedures for aircraft operating into and out of major USA airports.
This typically involves designated unpopulated areas and the fuel is dumped at higher altitudes so it atomizes and disperses before it hits the ground.
According to Flightradar24, Tuesday's flight never got above 8,000 feet and was at about 2,300 feet when it passed over Park Avenue Elementary School in Cudahy at 11:53 a.m. They did not need to be hospitalized.
A Russian cargo carrier, Volga-Dnepr Airlines, requested a regulatory exemption on Wednesday to fly a replacement engine for Delta from Minneapolis to Los Angeles aboard its massive Antonov An-124 jet "to respond to an emergency created by unusual circumstances not arising in the normal course of business".