The evacuation of Asiana Flight 214 in San Francisco on Saturday offered a textbook example of how to get more than 300 people off a plane after a crash and before it burns.
Flight attendants train once a year for evacuations, such as deploying slides like on Saturday on the Boeing 777. Only the four slides on the left side of the plane deployed, suggesting the right-side doors either jammed or crewmembers decided not to use them.
But all 307 people aboard were accounted for. Two 16-year-old girls who died were found outside the wreckage and 182 people were taken to area hospitals.
"It's incredible to see what these flight attendants were able to accomplish - with half the doors," said Leslie Mayo, a flight attendant for American Airlines on 777s and national communications coordinator for the Association of Professional Flight Attendants.
Flight attendants train for two sorts of evacuations: when they are warned about a looming crash and also when it comes as a surprise. It's not clear yet how much warning the crew had for the Asiana crash.
An example of a preparation came in Sioux City, Iowa, in 1989, when United Airlines Flight 232 had the center tail engine of a DC-10 fail while flying from Denver to Chicago. With 285 people aboard, 111 died.
Given a warning, flight attendants ensure passengers are in their seats, bracing for impact, and that those in exit rows are prepared to act. Warnings are issued for passengers to remain seated, and then leave without gathering belongings once the plane comes to a rest.
"People are standing there not knowing what to do. They are standing with their luggage - you literally take their luggage away," Mayo said. "This is not about your iPad. This is about your lives."
For an unexpected crash, flight attendants have trained repeatedly to open the emergency doors, which automatically inflate the slides. First, they check to see whether there is smoke or fire outside to avoid.
"I can open a door in my sleep," said Candace Kolander, a former 23-year flight attendant who now oversees air safety, health and security for the Association of Flight Attendants.
A key to getting passengers off quickly is to have them using all exits. Passengers are packed more densely in coach, while perhaps 16 are seated in first class in a 777.
Flight attendants call out to passengers to shift from one door to another if one isn't being used.
"If your exit dries up, you're going to walk in a little bit away from your door to see if there's anyone standing in the aisle, and use verbal commands to come toward you," Kolander said.
The Associated Press reported that police officers on the ground outside the Asiana crash threw utility knives up to crewmembers, so they could cut the seat belts of passengers trapped in the plane.
Flight attendants not involved with the crash said passengers will often help injured passengers off a plane.
"People don't usually run screaming or freaking out. It's an amazing thing to see," Mayo said. "They aren't necessarily worried about themselves. It is incredible to see how people are willing to assist."
Flight attendants will check the cabin for remaining passengers before leaving themselves, so long as dense smoke and fire aren't a threat.
"if the situation allows it, a flight attendant would go back in and do a sweep of the cabin," Kolander said. "If the situation does not allow it, then you need to get out and help assist on the ground with the emergency response."
The bottom of the slide is another spot where passengers can pile up. Flight attendants ask some passengers to remain at the bottom of the slide, to help other passengers get up, and then keep pace at the top of the slide in letting more passengers go.
"You touch another two - to say you, you - go to the bottom and catch people and help people out," Kolander said. "When they hit the bottom of the slide, that's where you could have passengers slowing down. You want people down there to pull them away and moving away from the aircraft."
Flight attendants train repeatedly, partly to reduce stress during an actual emergency. They urge passengers to listen to safety lectures because of differences between planes.
"Even if you are a frequent flier, the door locations are somewhat different, so that's what you need to look for," Kolander said.