Those side sponsons are fuel tanks, and the surrounding structure is not watertight, so it would not float well, nor for long. The problem with helicopters is that all the heavy parts (engines, transmissions, rotor head and rotors) are all above the centre of gravity, so when one winds up in the oggin, it almost immediately turns upside down and then behaves like a homesick flounder.

Even boat-hull helicopters such as the Sea Thing and the Mi-14 need to keep their rotors turning when they're on the water, which causes its own set of problems.

Any idea if the crew got out of that?

Even the Navy/Marine CH-46 needs additional floatation bags to keep afloat.

Rotor systems are very delicately balanced. The slightest thing to throw it out of balance causes the helicopter to beat itself to death in a heartbeat.

Ubisuck

The MH-53e is a mine sweeping Helicopter and as another writer replied the large sponsons are gas tanks.

As to floating... YES BUT...Notice the height of the aircraft the weight of the rotor and gearbox would roll the helicopter on its Back. Capsize!!!

If the main rotor is under power, and a blade hits the water the action of 15000 horsepower stopping would instantly destroy the airframe and kill those aboard.

If the aircraft were going down at sea the engines would be shut down and the pilot would auto-rotate to the landing that way the freely rotating blades would not destroy the aircraft (though the tail might come off)

The thing is, it will sink, it is so heavy (34376 lbs empty) it will not float for more than 15 seconds (in the book), but that is enough time to evacuate. The crews are trained for this.

I worked on the aircraft and at Sikorsky for a while in the last century.

Captn Tommy