The passenger plane was engulfed in flames soon after crashing with a coast guard plane.

Five of the six crew members on the smaller jets died.

But the nearly full Airbus A350 jet managed to evacuate safely in under 20 minutes.

But there are lots of things about that aircraft that helped to protect the passengers.

Here are some of the factors that led to this successful evacuation.

At 5:47 p.m. on Tuesday, Japan Airlines flight 516 and Airbus A350-900 traveling from Sapporo in northern Japan to Tokyo collided with a coast guard plane.

JL 516 was burning on the outside.

But crucially, it was not yet burning on the inside, and so the race to save its passengers started.

The way an evacuation usually proceeds is that once the plane has come to a standstill, the flight crew usually give the command to the cabin crew to initiate the evacuation.

And the flight deck will normally tell the cabin crew which side or which exits they can use.

Japan Airlines said it took some time to get the doors open because flight attendants first needed the pilots confirmation that the airplane had come to a complete stop and they needed to check whether it was safe to evacuate.

To operate around the world, aircraft manufacturers must prove to regulators that passengers can evacuate a plane in 90 seconds, using only half of the exits.

They conduct tests under conditions meant to simulate real life.

But experts say the tests often fall short of replicating real accident conditions.

It's only when you have a real accident like this that you get to see exactly how that works.

For the A350, there are four pairs of exits, so there are eight exits on the aircraft.

So the certification test would have been done with four exits.

Now, in the A350 accident at Haneda, we didn't have four exits.

We had three exits and we had two exits in the front.

So you're gonna have lots of people trying to use that front exit.

This is a sub-optimal evacuation situation.

Experts say the Japan Airlines crew did an impressive job to evacuate under difficult conditions.

Flight attendants asked people to leave their belongings behind and remove any sharp heels that might tear the evacuation chutes.

Welcome on board.

When you've got your big roller bag or your big rucksack or whatever, and you're going down the aisle, you're taking up much more space than a single person would.

And so that's making the congestion worse.

And finally, if you manage to get to the exit with the bag, and you take the big luggage down the chute that can damage the slide.

By 6:05 p.m., 18 minutes after the collision, the evacuation was complete and everyone on JL516 was safe.

Experts say the design of the Airbus A350 was also key.

More than half of the aircraft was built from carbon fiber reinforced plastic rather than aluminum like older planes.

The Airbus A350 is the newest Airbus aircraft.

It uses a composite fuselage as does the Boeing 787.

What we've seen here is that first serious event involving an A350.

We know that that aircraft met the design standards in terms of strength, in terms of how it might deal with the fire.

When you look at the fire, the aircraft seems to have done exactly what you want to do, which was protect the occupants for long enough that they could evacuate from the aircraft.

Airbus set tests show that carbon fiber composites may contain fire longer than an aluminum fuselage.

As it heats up, the aluminum loses its strength, and you could get the aircraft breaking on the tarmac, breaking its back.

Now with a composite fiber, it retains its strength for longer as it's being heated.

Every second counts. Every second can make the difference between life and death.

A Japanese Transport Ministry official said it was too soon to determine the cause of the collision, but a formal investigation would be conducted.

Airbus said it was sending a team of specialists to help the Japanese investigators.

The accident marks the first total loss of an Airbus A350 since its first flight in 2013.

The A350 is becoming one of the most popular jets for airlines around the world.

Experts say there are important lessons to learn from the Haneda crash.

For anybody flying, it's an incredibly safe method of transport.

But when things go wrong, there's a whole bunch of people who are working to try and keep us safe.

So you know, when you get on the aircraft and you feel grumpy with the flight attendant that you don't get your drink quickly enough, just remember that this is a safety professional and then that incredible evacuation, these were the last people off the aircraft.