Why an ordinary seat cushion can float
A seat cushion is useful in a water landing because its foam can provide buoyancy: tiny pockets of air in the material help it displace water rather than sink immediately. The cushion can therefore give a passenger something buoyant to hold while getting clear of the aircraft or waiting for rescue.
The seat is built so the cushion can be removed quickly. That simple design choice turns part of the cabin furnishing into an emergency aid without requiring passengers to find special equipment first.
A cushion is not a life jacket
A flotation cushion and a life vest solve different problems. A cushion is something to grip or lean against; it has no wearable straps to keep it in place. In rough water, a tired or injured person may find it harder to hold on than to use a properly secured vest.
That is why a cushion should not be treated as a replacement for the aircraft’s designated flotation equipment or crew instructions. Its value is practical but limited: if a passenger ends up in the water, a removable buoyant object is better than having nothing to hold.
