What would they do if the flotation device did not work properly or the plane flipped?

I don't know what happened because it happened so quickly but the plane flipped.

In short, the plane flipped over and pancaked flat on its back.

The shattered plane flipped over to port and went in nose first.

After a grinding crunch, the plane flipped over and plummeted toward the ground.

After coming completely coming off the runway the plane flipped and spun three times.

The plane flipped on its left side and rolled over, breaking in the middle and at least one other place.

But the plane flipped over in an attempted landing and 112 people were killed.

The plane flipped onto a grassy area short of the runway.

Some players yelled, thinking the plane might flip.