Warbird Information Exchange

Actually a pretty common practice since any action early on would take place a long way beyond ferrying range, the space is unused and a clever way to use it to good advantage.
The ribbing is an easy way to stiffen up flat sheet metal, and right up to the end of production, every DOUGLAS airplane including MD-11's used corrigated metal as maintenance stepways and sub flooring in cabin areas and as the walkway out of the tailcone escape corridor in the aft fuselage on every DC-9/MD-80 ever built was aproximately 1/2' X 1/2' waffled sheet of about .032 thickness.
Great tips for modellers in these as you see that just about everything inside and out was silver laquer and NOT interior green including flap coves and end ribs on wings.

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Don't make me go get my flying monkeys-

The flotation bags are a distinct feature of the TBD and certainly reflect the needs of a peacetime navy that could ill afford to lose very many of its precious aircraft (only 129 Devastators were ever built).

From what I've heard however, they may have caused as much (or more) problems than they solved. The bags were occaisionally known to deploy unexeptedly and ruin the crew's whole day.

The feature was still in place during the early days of the war. Veterans of the VT-5 ditching at Jaluit, Marshall Islands (1 Feb, 1942) spoke of slashing the bags and shooting them with their .45s to ensure that the planes would sink out of sight. Even if the Japanese had managed to locate and investigate the wrecks, they would not have found the top-secret Norden bombsights which had been removed by the bombardiers and thrown into the sea while the aircraft were still in flight.

Not just Devastators .. there are also 3 SBD dive bombers hanging from the overhead in that picture. Cast a careful eye for distinguishing Dauntless features such as dive brakes, center line swing style bomb rack and main gear retracted flush with the underside of the wings (rather than protruding down into the slipstream as with the TBD) and I'm sure you'll be able to pick them out.

DC-3 also has corrugated metal in the wing structure.

As did B-17's.

What exactly is going on in this picture? It looks as though the crewmen are being rescued from an aircraft dangling over the edge of the flight deck.


Wait, were the flotation bags actually intended to allow the recovery of the ditched aircraft? I thought they were only included to facilitate crew survival. I figured that the aircraft would have been sunk once the crew were recovered.


Why exactly were the landing gear designed that way? I'd guess it has to do with lessening the damage on a wheels up landing, like on the A-10. And why only on the Devastator and not other navy aircraft? Is this another case of the "needs of a peacetime navy" you were talking about?

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Tri-State Warbird Museum Collections Manager & Museum Attendant

Warbird Philosophy Webmaster

I would hypothesize that retractable landing gear was still in its infancy and aircraft engineers had yet to master retracting gear that could twist and turn (such as the P-40). If you look at planes designed in the same time period (B-17, DC-3, P-35), they have a similar landing gear mechanism, just a straight fore and aft motion, without any thought about recessing the wheels fully.

If you look at the performance of the TBD over its predecessors at the time it was introduced, it was such a quantum leap forward that I imagine no one really thought about the few more miles per hour you would have picked up from a full recessed gear. It has been said that the TBD was a great torpedo bomber by 1937 standards. Unfortunately, it went to war in 1942, when fighter technology had rendered it obsolete, but it was all we had until the Avenger became available.

Looking at the F4F and SBD, the lessons were learned that those few extra mph were definitely worth the effort to have fully retractable gear.

I've seen it written somewhere years ago that Boeing developed the twist and retract landing gear and CURTISS and GRUMMAN paid some license fee to Boeing on every airpane they built. Sort of like CESSNA paid Steve Whitman a fee for every spring steel landing gear assembly they installed over the years.

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Don't make me go get my flying monkeys-

Hmmm... The DC-3 was also (obviously) a Douglas aircraft. I was wondering if it could have been a company specific design feature as well. Although, probably not - your theory makes too much sense and looking at the aircraft models you noted above, Douglas wasn't the only one to do it.

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Tri-State Warbird Museum Collections Manager & Museum Attendant

Warbird Philosophy Webmaster

I imagine it's a combination of all of the points put forward.

At the speeds the aircraft are operated, the bump of the wheel sticking out is a minor source of drag, (especially compared to fixed gear just a few years before).
Retracting straight back (or forward FTM) is mechanically simpler and lighter than gear that turns, bends or otherwise contorts itself when going to bed. Fore-aft retraction also has a more benign failure mode in most cases. If the gear doesn't lock down properly, it's more likely to simply fold up without ripping itself out of the wing.
Ditto the exposed wheel can prevent greater structural damage in the even of collapse or gear up landing. Engines and props are less expensive than complete airframes.

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Lest Hero-worship raise it's head and cloud our vision, remember that World War II was fought and won by the same sort of twenty-something punks we wouldn't let our daughters date.