Aircraft Emergency Flotation Bags ...

[WIX_Archive]

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 .

[WIX_Archive]

But!!! do they work?!! ..................

Below is a series of photos of an early US Navy plane that ditched off the coast of California in 1938.

[Jim MacDonald]

I think that the photos of F4F 6-F-2 were taken in San Diego Bay. In the first photo it looks like the El Cortez Hotel in the background. Possibly the flotation tests were being based out of North Island NAS?

Mac

[CAPFlyer]

The prototype Corsair, in addition to have the wing bomblet bays, also had flotation bags. It was interesting to see their exclusion on the actual production aircraft, but hearing of their bad habit of not working properly, I see why. Last thing you need is for one of those bags to inflate in a 400mph dive on a target.

[JohnB]

Aside from making it easier to find the pilot, admittedly no small thing, the bags wouldn't save the airframe...did to the stresses of ditching and salt water immersion.

[Noha307]

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.

I remember reading a claim that they were removed from the TBDs to ensure that the aircraft sank quickly so enemy couldn't recover the Norden bombsight. However, given the amount of mythmaking around the Norden, I wouldn't be surprised if the real reason was the accidental deployments.

On the other hand, I found one reference that states claims the inadvertent deployment was the cause for the removal from the F4F, while the reason for the removal from the TBD was the Norden bombsight. So maybe it was a bit of both.

One other possibility: I can't imagine those bags were that small even when uninflated. They would have taken up a lot of very valuable space that could have been used for other purposes.

Also, Mark, one of the pictures in your recent thread about the D3A recovered at Pearl Harbor seems to show some deflated bags:

(Source: Flickr)

I guess the idea never completely left aviation, just transferred to helicopter landing gear, since we now have emergency flotation systems. Apparently the idea was around as early as the R-4, although I'm guessing this particular implementation was not just for emergency use:

(Source: Vertical)

[JohnB]

You are correct, large helicopter floats like that were for regular amphibious operations, not emergency use.
R
You see pop out emergency floats on oil rig transports and other helicopters like some of the Hughes 500s in the old Magnum, PI series.

The earliest pop out emergency floats I'm aware of were on
some civil Vertol 44s (H-21s) and the VH-34s used for Presidential use in the early '60s, likewise the Westland Wessex used by the Queens Flight in the UK.

[maxum96]

I think that the photos of F4F 6-F-2 were taken in San Diego Bay. In the first photo it looks like the El Cortez Hotel in the background. Possibly the flotation tests were being based out of North Island NAS?

Mac

Yup San Diego bay with the El Cortez Hotel in the background.

[Noha307]

Researching hydrovanes in the aircraft design firsts thread led me back to this one and eventually resulted in me searching out a few more pictures:

Curtiss Hawk:

(Source: WW2Aircraft.net)

Curtiss SBC-4:

(Source: Tumblr)

Grumman F4F Wildcat:

(Source: Warbird Information Exchange)

(Source: SDASM via Flickr)

Hanriot HD.2:

(Source: SDASM via Flickr)

Parnall Panther:

(Source: Their Flying Machines)

Westland Walrus:

(Source: Aviastar)

Manufacture at Goodyear in Akron, Ohio:

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

(Source: Library of Congress)

[JohnB]

There are several photos of them in use in the 2020 Ginter publishing F2F/F3F book.
The Navy...or Grumman...figured out how much of the fuselage would be above water and it was marked.

And to correct my old comment, the device did save aircraft and allow them to return to service following a water landing (like the JAL DC-8 but unlike Capt'n Sully's Airbus). The individual aircraft history section has several examples. However, one was scrapped after sinking and being in the ocean for 17 days.

[Noha307]

Grumman XF5F Skyrocket:

(Source: Warbird Information Exchange)

[Scott Rose]

Broken images restored

[CoastieJohn]

A casual memory.

In my old CG helo days...we would inspect and test the emergency float bag system on a scheduled basis. When we did water landings in the H-52's, we had to pull the bags out of their storage compartment, (a pouch on the side of the sponsons) and rinse them off. When done rinsing, we'd roll them back up and stuff them back into the "pouch" and get ready for the next flight. After we got rid of the H-52's and H-3's.....the new helo's (H-65's and H-60's) had float bags too but you only landed in the water once with those aircraft. A couple of times I remember seeing both the H-52 and H-65 limping back to the Airsta with the bags inadvertently blown. As mentioned above....some of our early CG helo's had float bags installed as part of the landing gear system. I have someone's silent home 8mm video from the 1950's of these helo's on an icebreaker up off Greenland on a Polar Ops deployment.

[Noha307]

Development of the flotation bag system in the United States was apparently spearheaded by Walter Kidde & Company, as they took out four patents for the system from 1930 to 1937:

• 2,039,014 - Release Mechanism for Aeroplane Flotation Devices
• 2,052,186 - Aeroplane Flotation Device
• 2,058,244 - Aircraft Flotation Device
• 2,073,688 - Aircraft Flotation System

Furthermore, the National Air and Space Museum has a collection of images from the company that include depictions of aircraft floatation systems.

EDIT (22-07-25): Correct spelling of company name.