of here's an explanation of how the us airways airbus a-320 floated on hudson river

Device helped ensure US Airways plane would float: This explains why the plane floated as it crash-landed on Hudson River.

Planes can float, but the US Airways Airbus A-320 that crashed into the Hudson River Thursday had a better chance than most.

That's because it was equipped with a special device unique to Airbus planes that increased the likelihood it would stay on top of the water.

The device, called a "ditching switch," effectively seals the plane by closing valves and ventilation ports, a spokesman for the airline said.

Industry experts said the ditching switch is rarely invoked, as "it's not as if anyone expects to ditch these planes," said Robert W. Mann, who owns a Port Washington-based aviation consulting company.