I'm not the only one who questioned whether a Delta B777 dumping fuel over Los Angeles made a lot of sense:
Fuel dumps occur only to reduce planes' weights for unexpected landings because some of them have maximum takeoff weights higher than their landing weights, said John Cox, a former US Airways captain who runs Safety Operating Systems, an aviation safety consulting company.
While the procedure is standard for an emergency landing, it can be accomplished more safely if it is done at a high altitude, allowing the fuel to evaporate before it reaches the ground, and it can be done over designated secluded areas.
"The question investigators are going to ask is that if you're going to dump fuel, why didn't you advise air traffic control, and why didn't you go where fuel dumping is approved, which would not be over a highly populated area?" Cox said. "If you had an on-board fire or something like that, it makes absolute sense to do that. But this was not that case."
The crew of Delta Flight 89 did not inform air traffic control that it was going to dump fuel, according to a review of communications, the Federal Aviation Administration said Wednesday. Typically, air traffic controllers direct planes to appropriate fuel-dumping areas, the agency said in a statement.
Apparently the airplane suffered a compressor stall, which doesn't usually affect the safety of flight. Fun fact: Boeing 777 airplanes meet ETOPS-207 standards, meaning they can safely fly for 207 minutes—up to about 4,000 km—on one engine. So even if the compressor stall took the engine offline, they could have flown back out over the Pacific to dump fuel.
Again, I'm looking forward to the NTSB report.