Mitsubishi Stuka and Thunderbolt

[MiloMorai]

Testing done by the USAAF found that the bullet pattern from ground testing had the following results for 12 rounds to 600yds:

For the B-17:

ball turret > dia. 15' - 8.3mils
upper turret > dia. 21' - 11.7mils
chin turret > dia. 23' - 12.6 mils
waist(closed) dia. 26' - 14.3mils
side nose > dia. 34' - 18.7mils
tail turret > dia 45' - 25mils

For the B-24:

ball turret > dia. 15' - 8.3mils
upper turret > dia. 20' - 11.2mils
nose turret > dia. 23' - 12.9mils (Emerson)
nose turret > dia. 35' - 19.3mils (Motor Prod.)
waist(closed) dia. 23' - 12.9mils
waist(open) dia. 63' - 35.6mils
tail turret > dia 35' - 19.3mils

source: "Gunner" ISBN 1-55046-332-2

This should be easy enough to replicate in game.

[Pursuivant]

Originally Posted by MiloMorai

Testing done by the USAAF found that the bullet pattern from ground testing had the following results for 12 rounds to 600yds:

This is very good information, the sort of quantitative data that's hard to come by. Thank you for posting it. Since the numbers for the gun positions on the two different bombers were reasonably close, the data could possibly be used for similar weapons mounted on other U.S. bombers, like the B-25 or the A-20.

[horseback]

Originally Posted by Pursuivant

This is very good information, the sort of quantitative data that's hard to come by. Thank you for posting it. Since the numbers for the gun positions on the two different bombers were reasonably close, the data could possibly be used for similar weapons mounted on other U.S. bombers, like the B-25 or the A-20.

The data for the open waist positions is the most relevant to the majority of man-served guns; it was a pintle-type mount rather than one in a reinforced ball socket mount, similar to the majority of the rear gunners in the sim. Scharf ring and pintle mounts are much more subject to vibration and flex.

Note also that the data is for ground testing, which means that there is no relative motion to joggle the gunner's elbow or guesstimations about where the target was going to be when the bullets got there. Chances are good that the guns were sighted in and then clamped down and fired by a fixed remote to get those figures in order to eliminate human error.

cheers

horseback

[horseback]

This might be a bit too extreme. Some planes flying solo really did shoot down multiple enemy aircraft - or at least damage them seriously enough that they were "probables" and out of the action. So, aerial gunners weren't completely useless - especially the tail gunners who accounted for a majority of the 8th Air Force gunner aces. It's also worth mentioning that the USAAF kept tailgunners long after they ditched every other gunner position (last tailgunner kill was over Vietnam).

Most of the stories we hear about a solo aircraft's gunners managing to destroy or damage attacking single engine fighters usually turns out to be apocryphal if we try to investigate; about 20 years ago, I was commissioned to build a 1/72nd scale B-24J with the markings of a Foggia based aircraft that was shot down in the sort of circumstances you describe for one of the surviving aircrewmen. I was invited to the presentation, and the honoree confessed to all present that the claims of four or five enemy fighters destroyed in their heroic last fight (over Turin, I think) were all bulls**t (his word, used as he pointed right at the Groups' former Public Information Officer), but he wasn't giving his Air Medal back.

As for the B-52's stinger, the 'gunner' operated a radar aimed gun remotely, with the help of a slightly more advanced stabilization system than that used on late-WWII era battleships's guns. It took shameless advantage of the limited range and acquisition cone of early Warsaw Pact heat guided missiles like the Atoll.

But, as you said, the USAAF (and every other Air Force) had problems with overclaiming kills. Often, when some hapless Bf-109 diving through a formation B-17 or B-24 coughed up smoke because pilot mishandled the fuel mixture, every gunner in the formation would claim it as a kill because they saw the 109 coughing up black smoke were sure that their gun was the one that "hit." With claims like that, even the most skeptical debriefing intelligence officer was likely to believe that the fighter was a "probable" even if the Luftwaffe plane wasn't scratched.

Almost any Allied fighter pilot in the theater for more than two days (i.e., long enough to visit the Officers' Club bar) could have told them that German fighters tended to belch black smoke whenever the throttle was shoved forward or back too quickly, and the Allies' commanders were well aware that the Luftwaffe wasn't taking even a tiny fraction of the losses the the gunners claimed to be inflicting. "Morale" was the only justification for awarding the overwhelming majority of gunners' claims for destroyed enemy aircraft, and they beat it to death.

cheers

horseback

[Pursuivant]

Originally Posted by horseback

Most of the stories we hear about a solo aircraft's gunners managing to destroy or damage attacking single engine fighters usually turns out to be apocryphal if we try to investigate

Interesting. Do you have any further info to back up this claim? I'm not disputing you, I'm interested in actually figuring out what was actually going on, and I've always wondered just how good gunners actually were.

I have to wonder if it wasn't a huge amount of institutional inertia that led to bombers being heavily equipped with gunners. After all, there is a strong tendency to "fight the last war," and during WW I gunners really were a threat given the relatively short range, limited damage and poor accuracy of the frontally-fixed fighter machine guns. But, by WW 2, many WW I pilots were colonels and generals, so they might have figured that if one or two men armed with single .30 caliber MG were good, 7-8 men armed with multiple 0.30 or 0.50 (or even 20 mm) MG were even better, without realizing that higher airspeeds made gunnery much less effective.

Arguably, the best strategy for bombing during WW2 was the Mosquito - two man crew, decent bomb payload and a very fast aircraft to make interception difficult. You send them out knowing that fast fighters and flak are going to get some of them, but low manpower requirements and relatively inexpensive design means that you can absorb the losses and win via attrition.

Instead, it seems to me that most air forces made huge design sacrifices, as well as operational and human sacrifices, to load up their bombers with gunners who literally might not have been worth their weight.

Originally Posted by horseback

As for the B-52's stinger, the 'gunner' operated a radar aimed gun remotely, with the help of a slightly more advanced stabilization system

Yep. But some of the later WW2 era bombers at least had tail warning radar, even if they didn't have radar-guided and stabilized guns. My point is that the "least useless" place to have a gun on a bomber is the tail, and tailgunners (or other gunners who faced to the rear) generally had the least
complicated firing solutions. I forget the exact numbers, but most of the gunner "aces" of the 8th AF were tailgunners, with top-turret gunners coming in next.

Originally Posted by horseback

Almost any Allied fighter pilot in the theater for more than two days (i.e., long enough to visit the Officers' Club bar) could have told them that German fighters tended to belch black smoke

Yeah, but if you've got an entire squadron of gunners swearing to God that they saw big trails of black smoke, and a few guys claiming they saw fire (due to reflections, tracers, sun glare, or whatever), plus one or two guys saying that the plane was diving "out of control" then a credulous intel officer might let the claim stand.

Eyewitness accounts are pretty damned unreliable, especially in the heat of combat. But, until you realize that, you might believe "they were there, they saw it, who am I to dispute them."

[Pursuivant]

Originally Posted by horseback

Note also that the data is for ground testing, which means that there is no relative motion to joggle the gunner's elbow or guesstimations about where the target was going to be when the bullets got there. Chances are good that the guns were sighted in and then clamped down and fired by a fixed remote to get those figures in order to eliminate human error.

It might be possible to find the actual technical report in the National Archives. That would settle a lot of questions about methods

In any case, TD now have actual factual data for the ABSOLUTE BEST accuracy possible using certain guns, which could be extrapolated for other types.

What would really be useful is if the USN or USAAF did studies on accuracy of pintle or Scarff-ring mounted rear-facing guns.

Or, even better, did any Air Forces keep records on relative gunner accuracy during training missions against aerial targets? Were there acceptable "Go/No Go" standards for aerial gunnery against target drogues in order to graduate from aerial gunner school? At least for the USAAF, it might be a bit easier to find that sort of data since Clark Gable was an air gunner (and, unusually, a commissioned officer). Stuff that might have otherwise been tossed at the end of the war might have been kept for sentimental reasons if it involved a movie star.

[MiloMorai]

My Dad was a WAG in the RCAF and during training and his instructor wrote `excellent` in his log book for a 5% hit on the drogue, if that is any help Pursuivant.

Typical was 1-2%.

[horseback]

Originally Posted by Pursuivant

It might be possible to find the actual technical report in the National Archives. That would settle a lot of questions about methods

In any case, TD now have actual factual data for the ABSOLUTE BEST accuracy possible using certain guns, which could be extrapolated for other types.

What would really be useful is if the USN or USAAF did studies on accuracy of pintle or Scarff-ring mounted rear-facing guns.

Or, even better, did any Air Forces keep records on relative gunner accuracy during training missions against aerial targets? Were there acceptable "Go/No Go" standards for aerial gunnery against target drogues in order to graduate from aerial gunner school? At least for the USAAF, it might be a bit easier to find that sort of data since Clark Gable was an air gunner (and, unusually, a commissioned officer). Stuff that might have otherwise been tossed at the end of the war might have been kept for sentimental reasons if it involved a movie star.

The Navy and Marines used more pintle/ring mounted guns on their dive & torpedo bombers than the Army used; the various float planes launched from the cruisers and battleships also had rear gun installations. I retain the impression that the pre-war trained Navy gunners had a pretty high standard for accuracy, much like the pre-war Naval Aviators (Dave McCampbell was a chain-smoking guy in his thirties when he rang up his score; you have to wonder what John Thach, one of the other acknowledged 'Top Guns' of the prewar era could have accomplished in a similar position).

As for my description of how the gun mounts were most likely tested, sighting the guns in and then clamping the gunner's end down gives you the dispersion inherent to the gun mount type; humans are terribly non standard as a rule (even from minute to minute), so you would want to limit their influence as much as possible.

MiloMorai's numbers sound about right for shooting drogues flying in formation with your aircraft; 5% for a steady state target unlikely to shoot back.

cheers

horseback

[Pursuivant]

Originally Posted by horseback

The Navy and Marines used more pintle/ring mounted guns on their dive & torpedo bombers than the Army used

That's why I was asking about them. If you could get decent stats for inherent accuracy of rear-mounted pintle/ring-mounted guns from the USN, then it would be very easy to extrapolate it to similar gun mounts used by other air forces. All the mounting technology was roughly comparable (although gun performance differed a bit) and the human element was probably pretty much the same worldwide.

[horseback]

Quote:
Originally Posted by horseback:
Most of the stories we hear about a solo aircraft's gunners managing to destroy or damage attacking single engine fighters usually turns out to be apocryphal if we try to investigate

Interesting. Do you have any further info to back up this claim? I'm not disputing you, I'm interested in actually figuring out what was actually going on, and I've always wondered just how good gunners actually were.

Not much beyond the few times I've tried to look up the reports of aircraft like "Pistol Packing Mama's" last fight, and been able to find nothing to actually confirm beyond reports that usually came from people in no position to see what happened.

I have to wonder if it wasn't a huge amount of institutional inertia that led to bombers being heavily equipped with gunners. After all, there is a strong tendency to "fight the last war," and during WW I gunners really were a threat given the relatively short range, limited damage and poor accuracy of the frontally-fixed machine guns. But, by WW 2, many WW I pilots were colonels and generals, so they might have figured that if one or two men armed with single .30 caliber MG were good, 7-8 men armed with multiple 0.30 or 0.50 (or even 20 mm) MG were even better, without realizing that higher airspeeds made gunnery much less effective.

I've made exactly the same general argument myself on more than one occasion.

I think that the momentum was in place by 1930 or so, with Douhet's 'the bomber will always get through' dogma, coupled with the way that big multiengine aircraft were outperforming the single engine fighters of the same period. I'm sure that the Powers That Were assumed that the fighters would never become as fast, long ranged and heavily armed as they eventually did (or if they did, they assumed that they themselves would be safely retired by then). In the cash poor Depression era US Army Air Corps, big bombers offered a lot of bang for the taxpayers' buck (and they looked quite impressive).

A lot of the men who were generals in 1942 made their marks in the early-mid 1930s as advocates of this strategy before the development of radar made locating the bomber formations a lot less chancy, and fighter aircraft became not only as fast and high flying as the big bombers, but much more so. These generals and the big aircraft companies that built the big bombers had already made a major investment in the concept before the war though, and probably really did believe that the Germans and the RAF simply hadn't used big enough formations of aircraft capable of flying as high and fast as the B-17 or B-24, with enough well trained men at heavy machine guns to swat away the few fighters able to get to altitude in time to intercept.

By the time reality had set in, it was late 1943, and the war machine had poured billions into bomber production, trained aircrew and propaganda, not to mention lost thousands of lives. You could quietly reassign the less senior responsible parties to training commands and early retirement (after the war) but you couldn't tell the world, the taxpayers (a large subset of which had become Gold Star Mothers due to your miscalculations), the 'crusading' politicians and especially the enemy that you had been terribly wrong.

Rosie the Riveter would find you and kick your *%&$$!!! and that would be the least of your problems.

Better to re-purpose the bombers and let the new long range fighters destroy the Luftwaffe (and its pilots) in the air after using the bombers to get them to come up and fight; once the fighters finally established air supremacy, you could finally use the bombers to destroy the enemy's industry, starting with fuel and lubricants, and gradually reducing the surface of his territory to a moonscape for the sake of bragging rights and a shot at a role in creating a separate Air Force and maybe even take over the aviation arms of those arrogant bastages in the Navy and Marine Corps, all while saying that was how you had planned it all along.

As RoseAnne Rosannadanna used to say "It could happen."

cheers

horseback