Images originally posted by Mark Allen.
Several photos showing rubberized fabric spherical bags attached to airplane wings which, in the event of crash landing at sea, are inflated from compressed air cylinders so as to support the plane in water.
The problem was, the bags had a tendency to inadvertently deploy in flight. When this happened, the bags acted like giant spoilers, destroyed lift, and effectively stopped the wing from flying.
After several aircraft were lost (and at least one pilot was killed) due to these inadvertent deployments, the system was abandoned.

Woman worker applying the finishing touches to a flotation bag.

Vought SU-3 Corsair with bags deployed.
Below: Three photos of a Hawker Hart with Flotation Bags RAF 33 Squadron.



In the early 1940's, Grumman and the US Navy tested emergency flotation bags on Grumman F4F Wildcats.
These bags were stowed in the wing. In the event of a ditching, they deployed upward through doors in the leading edge to prevent the aircraft from sinking.



Grumman XF4F-3 Wildcat VF-6 White 6F2 during the factory stage to produce a floatation device.

Grumman XF4F-1 Wildcat

Douglas TBD Devastator with flotation bags.

Curtiss A-12 Shrike No. 26 with emergency flotation gear - test inflation. Photograph taken May 6, 1937.

Flotation Gear on a Curtiss F6C-3 Hawk on factory floor, April 25, 1928 .