THAT DOESN’T SEEM VERY FAST: 18 Minutes to Evacuate a Burning Plane: Success Story or Cautionary Tale?

In its certification, Airbus AIR 0.23%increase; green up pointing triangle

was required to prove that its A350 aircraft can be evacuated in less than 90 seconds. In Tuesday’s collision in Japan, the last crew member escaped the aircraft after 18 minutes—but there were still no casualties.

The sizable discrepancy, for the moment, represents a puzzle for the industry: Does the safe and deliberate evacuation represent a triumph of new aircraft designs and improved procedures? Or was it a one-off, a fortunate confluence of events that doubles as a cautionary tale showing how difficult it is to quickly evacuate modern aircraft?

Aircraft safety and evacuation experts are applauding Japan Airlines’ 9201 -0.36%decrease; red down pointing triangle

cabin crew and passengers for escaping the burning wide-body plane without any loss of life before its fuselage collapsed. In doing so, they avoided what could have been one of the most deadly plane crashes in decades.

“Obviously it took a lot more than 90 seconds, but even though it did take longer, it was a very organized and a very orderly evacuation, and it was impressive,” said Anthony Brickhouse, an associate professor at Embry-Riddle Aeronautical University and director of its forensic crash lab. “This is a great case study.” . . .

“The 90 second rule is there for a reason, because that aircraft can obviously be incinerated in seconds,” said Sara Nelson, international president of the Association of Flight Attendants-CWA, a union that represents cabin crew at several airlines. “The flight attendants appear to perform their jobs perfectly, but the question remains what was that configuration of the cabin? How close were the seats together? And who was on board?” . . . Planes have gotten bigger since such demonstrations were introduced following a 1965 crash in Salt Lake City. Passenger weight and girth have climbed in recent years, and seat spacing on many planes is tighter—developments some have argued regulators haven’t adequately considered.

I suspect that tightly-packed seating arrangements don’t help.