20mm Gatling for tailgunners

For the first time in my life i'm talking to a bunch of people that don't need explanations of things, so heres my question:
Given the importance of the tail gunner...most enemy fighters wanted to come up from behind and fire a "straight shot" where every round has a chance for a hit...so the tail gunner suffers more than anyone on a bomber (Bottom turrets not too cool either!) So, given the importance to the entire bomber and crew of the tail gunner, why wasn't a gatling gun used? Either .303 .50 or 20mm?
We have all seen in the history books and in movies the gatling gun, hand cranked, gravity fed jobs mostly. And today we have gatlings and mini-guns in almost everything.
The B-52 used a 20mm gatling in its tail, so if the concept needed proving, the B-52 is it.
My thinking is that if you have a zip line of 20mm tracer rocketing toward you, NO enemy fighter is going to come in close and only stay on station for a few seconds before getting the heck out of there! It would force the enemy into a deflection shot, drastically reducing the hit-kill rate.
I posted this question a while back on an aviation site and got some half decent replies (particularly from some Viet vets). The general consensus was that they never thought of it! (Redesign was taken as red).
A flattering answer for me perhaps, but a little unbeleivable non-the-less.
Anyone care to shed some-hard core-knowledged up-answers?

 

A 'gatling gun' takes up a lot of space to operate and there simply was not room in the tail section for the gun, gunner, ammunition and feedways. The other thing to consider is that guns such as the current GAU-2B, GAU-8 or the M-134D just didn't exist back then at the level they do now.

I am sure if they were around during WW2, like they are today, LeMay would have strapped them on to something; I think the ammunition load would have adversely affected the bombload though.

 

It's not a silly question and indeed, one which occurred to the USAAF during WWII, particularly with the appearance of the Me262.Rather than go into long detail, perhaps its best to say the the modern 'Gatling cannon' belongs to the jet age. It was introduced during the late 1940s as a direct response to the threat posed by fast-moving jet fighters. And, as formerjughead has pointed out, the weight and complexity of the gun and ammo were a significant factor perhaps best overcome by being installed in jet-propelled bombers.

Piston-engined WWII bombers always faced a terrible trade-off between weight of ammunition and bomb payload. The Lancaster was under-gunned, but could carry a ( for the time ) huge payload. The B-17 was far more capable in the defensive role, but couldn't deliver large payloads.

 

It was also an answer to the famous "dead angle" (the bomb hatch for bombers without a ball turret) which was the weak spot on the Lancaster and the the Halifax for example.
Not only the Germans would not face the Tail gunner and attack from below , but the famous "Schräge Musik" gun burst would appear to come out of nowhere, to the point that some crash survivors could not tell precisely who hit them.

For day bomber Operations, one German innovation (first tried by egon Meyer) to avoid facing the rear gunner(s) would be to attack from the front and stay right in the pitch. This would prevent gunners from shooting at the enemy for fear of hitting their own friends.

 

Other than a modern gatling gun being incredibly heavy, it requres power to operate it and, it uses a prodigious amount of ammunition. All three of these argue against its use in WW 2 aircraft.

As for attacking bombers, the best method is the high or low side pass (high being prefered). In this method the attacking fighter approaches head on above and to one side of the bomber. This makes it a fast approaching target requiring a high amount of deflection in shooting something most defensive gunners were not well versed in. The fighter when it got about even with the bomber would then make a diving turn into the target (a downwards immelmann sort of) and attack the bomber from abeam just aft of the wing when done properly. This made the deflection fairly simple as the pilot just aimed a bit ahead of the nose and would then rake the plane's center section with fire.
The whole time the fighter presents a deflection target making defensive gunnery difficult and avoids most of the rear facing defensive guns.

 

Others have provided good answers, so I'll only add one point. The weight involved with the Gatling gun installation not only affects the overall weight of the aircraft, but that much weight mounted that far back would have a serious impact on the Center of Gravity (front to rear balance) of the aircraft. It would have been extremely difficult to add that kind of weight to the tail of an existing design and keep the COG in the proper range.

 

As pointed out vs B-17s and B-24s both Germany and Japan found that head on attacks were the best bet. I have read that powered Gatling guns were esperimented with prior to WWII perhaps even prior to WWI but after the initila experiments seem to have been forgotten until after WWII.

 

Must inform all of you but the best method of attack by the LW was from the rear slightly above or from slightly below, developed as standard from the summer of 1944 till wars end when they still tried to knock down US heavies but in vain. the Sturmgruppen all 3 of them proved this to be true. I have countless first person accounts from both sides, knock out the tail position and the US bomber is doomed .........

attacks from the front utilized in 1943 till spring of 44 were almost suicidal due to the closeness of collision. In fact several aces fell during these close encounters with the Bombers.

the Gatling gun was in no way needed let alone could be fitted in the US bomber tail position with the technology developed at the time.

Have a great and pleasant day Gents.

 

I could see an application for it in the B-25 / A-20/ A-26 ground attack/ anti shipping roll; IF it had been developed enough. The other issue is that John Browning didn't develop it.

 

Of course the aircraft would need a re-design or even another bomber designed around it...I totally understand the trade off between defence and bomb load...But....The less you lose in bombers, the better and more experienced the crew become, plus NO bomb load is going to be dropped if the aircraft doesn't make it to the target at all. This here is a sign or illustration of how the bombers and crew were considered secondary to the target. Not only morally wrong but had some question marks militarily. The change in centre of gravity would have to be addressed, position the bomb bay differently to compensate...again may need a whole new aircraft. The amount of rounds needed is irrelevent except in terms of weight and disposal, the gunner trained to use small accurate bursts, as i have said, this was all proved in the B-52. The gun could even be radar guided (i know, i know...)
Frontal attacks are NOT the answer, chin turrets were soon fitted to counter and the closing speed means less time to position, less time to aim, and less time to fire (less metal in the air - less damage). Rockets (which gerry adopted) would have been a decent counter to the gatling...come in, fire quick and tear off, the rockets still being able to do considerable damage as opposed to bullets, or cannon rounds fired in the same time.

 

The tail gun was/ is remote operated in the B-52 and it was an M-61 Vulcan, much smaller footprint than the GAU series or a true gatling gun.

 

m61 IS a 20mm gatling isn't it? Or at least a gatling type (name is after the inventor i think not the actual machine or mechanism.) What is a TRUE gatling?

 

What do you mean a "TRUE" gatling? The design of a set of rotating barrels around a center axis is Dr. Gatling's design. The General Electric adaptation to create the "Vulcan" automatic, rotating barrel cannon is by definition a "Gatling" design.

I mean he came up with the idea, others have improved on it. Dr. Gatling himself couldn't possibly imagine what would be produced out of his hand cranked, multi-barreled weapon. He designed it to make the firepower of a set position so frightful that "war" would be seen as a losing proposition. Sorry Dr. Gatling, that wasn't what happened.

 

Even a 29? I know, i'm sh*t stirring. Good point though. So you think they didn't think of it because it wasn't in the realm of possibility in the first place? Or thought of it and dismissed it?

 

Hand cranked old school.

I think the only itteration that would stand a chance of fitting in the tail position of a B-17 would be the current M-134D in 7.62MM.

Another consideration is the affect of lighting off 3,ooo rds of 20 mike on the controls of the aircraft (Newtons 3rd Law: Action and Reaction). The 8 .50's in the nose of a B-25 / A-20 / A-26 was enough to slow forward air speed when fired so what affect would 6 .80 cals have when fired from the rear of all the control surfaces have on stability?

 

When you consider that all the major aircraft that fought in the war were either in production or already on paper at the beginning of the war, suddenly designing a new aircraft around the gatling cannon becomes a very big issue.

The only US aircraft on which design was started after the US entry into the war that came close to seeing combat was the F8F Bearcat, and it only got close.

Pushing for range extention of escort fighters was the real solution to bomber protection. It was late '43 when the crisis in bomber protection came. Five months after 2nd Schweinfurt, US fighters were over Berlin. No way to get a new bomber design there.

 

The B-29 might have been able to handle a powered gatling gun. If Boeing B-29 Superfortress - Wikipedia, the free encyclopedia is right early B-29 had a pair of 50 cals and a 20mm in the tail. I would think a 3 barreled gatling gun wouldn't have taken up much more space indeed if it had been 12.7mm possibly less.

 

Space was indeed an issue, especially for the ball turret.