The B-17 was used for a significant portion of the Allied campaign during WWII. My understanding is the earliest bombs in aviation consisted of just throwing stuff out of the open cockpit of planes. Later this progressed to some doors in the fuselage through which bombs simply fell out when opened.

The B-17 appears to have a more complex bomb bay system, with doors and with the bombs mechanically retained somehow. Did Allied crews ever experience difficulty getting the bombs to release? How did they deal with this (landing with bombs seems dangerous)? Does any data exist for what percentage of missions encountered problems with the bomb release mechanisms?

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    The evidence (based on how much stuff blew up on German soil) suggests that whatever difficulty was had was overcome far more quickly that the US submarine fleet's problems with torpedoes that did not work. (See Lockwood's efforts to sort that out with BeauOrd during WWII). Given that it began service around 1939 and was already in service by Dec 1941, most of the bugs had been worked out. Feb 7, 2017 at 2:52
  • I have never read any source describing problems related to bombs release. Usually bombers problems were their armor, defensive guns and navigation.
    – Santiago
    Feb 7, 2017 at 12:09
  • @Santiago, it could happen. More of a problem with underwing hardpoints, of course.
    – o.m.
    Feb 7, 2017 at 17:25
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    For bombers returning to England with unused bombs in WWII, there were designated areas in the English channel for jettisoning the bombs...
    – DJohnM
    Feb 7, 2017 at 21:46
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    We have Aviation.SE; this question should have been asked there.
    – Vikki
    Dec 13, 2019 at 23:24

4 Answers 4


B-17 had, in fact, two primary release mechanisms - electrical release device and a manual lever. The standard procedure would be to first use electrical release, in case of failure - the manual lever. If both failed, either bombardier or waistgunner would have to get on the catwalk in the bomb bay and physically dislodge the jammed bomb with whatever they had on hand - this process is detailed in many memoirs, for example, here. I am not aware of any historical documents containing any particular statistics on this matter, though.

Also, as o.m. noted, it's not like B-17 had a significantly different bomb bay rigging as any other contemporary bomber, and even to this day release mechanism failure remains a common occurence on combat aircraft.

  • Did you mean to include a link to a Cyrillic text in your answer?
    – Eric Urban
    Aug 30, 2017 at 13:59
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    @EricUrban I didn't quite get what the problem was, since the book is properly displayed in english when I follow that link, but edited it to use .com domain anyway. Aug 31, 2017 at 3:08

I think you are misunderstanding the development of bomb bays and underwing shackles.

The period of hand grenades thrown from open cockpit lasted only a few years. In the interwar period one would see something like this video.

Bombs outside the aircraft add drag, so the next step was to put the bombs inside, but they would still be held in shackles. This is a B-17, a B-24, and this is a British Lancaster, and you can see how each bomb was individually held.

  • Related is that the vaunted Norden Bomb Site was not used much, at least according to one crewman I saw interviewed. He said basically they just got over the target and let the bombs go. I can see why, while being subject to flack and enemy fighters, one would want to drop bombs and get out of there but I wonder if the site if used (and maybe it was) made that much difference.
    – Jeff
    Feb 7, 2017 at 8:27
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    @Jeff In 1943 8th Air Force changed from each individual bomber sighting to a tight combat box formation where only the lead bombers with the best bombardiers were aiming. Everyone else dropped when the lead bomber dropped. Because of the tight formation, this gave a better chance of hitting the target.
    – Schwern
    Feb 7, 2017 at 11:44

My dad was the top turret machine gunner on a B-17g in England. One time the bombs did not release so he used a screw driver on the catwalk to release them one at a time. Possibly since he was the First Engineer he had trained on this? I believe they just dropped them one at a time in the countryside. Not sure which mission it was and if over France or Germany.


There were two ways to open the bomb bay doors: Electro-hydrolic and a manual crank.

Bombs had a pin that was tethered to the Bombay by cables. When the bombs fell, it pulled the pin. They also had a spring wound fuse and vanes that would unwind the spring as the bomb dropped. These were set to detonate the bomb at a specific altitude.

Bombs were normally released by electronically activated solonoids that automatically relased the bombs at a 1-20 millisecond interval.

If the electronics failed to release the bombs. The pilot had a mechanical release next to his left foot, the infamous "green apple". It was called the green apple because the screw on ball was green.

If either the hydrolics or crank could not open the bomb bay doors. The pilot would resort to the green apple. B-17s carried 6000 lbs. of bombs. Dropping this weight on the damaged bombay doors usually did the trick. It was clearly a last resort as it was not without significant risk!!

The answer to your question is YES, FLAK damaged the bomb bay doors quite often.

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    Hi Gregg Chapman and welcome to History SE. Adding sources would improve your answer. May 7, 2020 at 22:49

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