Bombers defensive armament: a misconceived idea?

[Udet]

I would like to focus exclusively on certain bombers within the thread, leaving aside ground attack planes and interceptors which were equipped with defensive armament.

The Battle of Britain saw Luftwaffe´s He111s, Do17s, Ju88s bombing targets all across central/southern England.

While each of the 3 bomber models were equipped with defensive machine guns -the number of guns depending on the bomber model- the German notion did not rely on defensive armament to ensure survival of the bombers. The Luftwaffe rather saw speed and maneuverability of its medium bombers to make interception an unlikely event -even if this was a pre world war two notion-.

They also relied on fighter escort which would be provided by the Bf110Cs (Zerstörer) as the BoB progressed.

Both notions were proved wrong once put into practice over England: the Luftwaffe bombers, while indeed fast for bomber standards, were uncapable of outspeeding the RAF interceptors and the "Zerstörer" did not perform well as bomber escort.

The Battle of Britain, however, saw the vast majority of the planes involved, German and British alike, armed with very light caliber armament: RAF´s fighters had .303 Browning caliber machine guns while the Germa bombers mainly carried 7.92 mm machine guns (either MG15 or MG81) for self defense. The exception to this rule was made by the cannon armed Bf109E-3 and Bf110C.

So as you can see, German bombers defensive MG´s were of a caliber slightly higher than the guns of RAF interceptors.

I have several combat film recorded from the cockpits of Do17s and Ju88s showing the German gunners setting Hurricanes and Spitfires ablaze during the Batlle of Britain. (I also hapenn to have rear gunner camera footage of a Stuka, where a Spitfire tailing the dive bomber is set on fire and disengaes in a cloud of smoke and fire, to immediately dissapear from the camera sight).

So far, it seems like most of us think of the USAAF heavies (B24s & B17s) shooting down German interceptors with their big number of defensive machine guns. The German bombers during the Battle of Britain certainly killed a number of RAF interceptors, however, that is not the topic.


However, it was the USAAF´s 8th Air Force who pushed the bomber defensive armament theory further down the spiral.

They were firmly convinced, on paper, the massive boxes of heavy bombers such as the B17 and B24, fitted with up to 12 .50 cal defensive machine guns, were powerful enough to look after themselves from German interceptors and to accomplish their bombing runs then return safely to base and have a warm dinner. Fighter escort was not considered a necessary element.

While on the paper, the theory appeared to be sound, for the B17 indeed made a sound massive all metal aircraft packed with defensive machine guns capable of taking a good deal of damage and still be flying, once it got put to practice battlefield reports proved them very wrong.

Different notions for bomber formations:

(a) Luftwaffe in 1940: speed and maneuverability/fighter escort.

(b) USAAF 1943/early 1944: soundness of the construction of their heavy bombers/ heavy defensive armament.

Both theories with different grounds each were failures.

Still, the failure of the USAAF heavies was a disaster which surpassed that of the Germans during the Battle of Britain, both in terms of bombers and aircrews lost.

The German pilots very soon learned on the weaknesses of the defensive fire of the "heavies" and immediately started destroying big numbers of those.

The bombers while of course capable of shooting down a number of Luftwaffe interceptors proved very vulnerable.

The 2 Schweinfurt and the first Ploesti raids conducted by the USAAF, while being representative cases of terrible disasters, are only a percentage of the failed USAAF doctrine on heavy bomber boxes.

You are talking about so many days when hundreds of USAAF bomber crews simply did not return for dinner and had to be erased of the 8th Air Force order of battle for good.

Yes, several of those who made it through could hit the targets but not with the requiered intensity to put German industry at jeopardy.

The daylight unescorted bombing missions brought an attrition rate for the USAAF in terms on bombers and crews, not even a large country with massive resources could afford.

Conclusion: flying unescorted the bombers lose to fighters. No matter how heavily packed with guns your aircraft is if it is very big, very clumsy and totally uncapable of maneuvering. The B17s and B24s on their own are losers.

Your much smaller and perhaps "less" armed (by no mean implying the fighter armament wasnt powerful) but very fast and very maneuverable foe will bring you down in bigger numbers.

Meeting with USAAF veterans, they accepted the claims of the USAAF gunners reached levels of insanity. On return to base, those who made it through, would claim numbers of fighters which simply surpassed the whole order of battle for the Lufrtwaffe in the combat area.

Example: they could return claiming to have shot down 40 fighters, while during the complete bombing run they were intercepted in total by 35 fighters.

Only until fighter escort arrived the "heavies" improved their combat performance.

What are your thoughts?

[the lancaster kicks ass]

very good points, that's what annoys me, people always talk about the american bomber's huge armorment, but even 13x.50cal wouldn't give you much of a chance against a fighter attack, another similar thing that annoys me is when people say the british bombers lacked defensive armourment, however we developed numerous measures to counter the threat of night fighters, many were extremely effective, Flight Sergeant Tom J. McLean, a tail gunner with 617 Sqn even became an ace in his own right after gaining the tally of 5 confirmed kils and one probable, if i get round to it i'll post his story at the weekend.................

[cheddar cheese]

During the BoB, the Dornier Do-17 was equipped with experimental Flamethrowers in the rear. They were largely a failure however, and just squirted oil everywhere.

[Udet]

Lancaster, I do think I agree with you.

The Avro Lancaster, for instance, carried too powerful defensive armament, although of smaller caliber than those of the USAAF, carrying up to 8 .303 Browning machine guns.

As I am sure you know Lancaster Kicks Ass, the RAF bomber command faced an extraodinarily professional weapon: the Luftwaffe´s NJGs, and losses of the RAF were very high many times as well, if smaller to those of the USAAF though.

While I have never ever read it on any book of my private library, it appears to me like if the British, when knowing of the intention of the 8th Air Force to conduct bombing missions in daylight "because or big heavy bomber boxes will deal with the German fighters", thought to themselves: "Ok sods, go ahead and have a lovely flight" and simply said: "Ok Sir, in view of your insisting and since you are our guests, we, the RAF, will have to take the night shift."

If you remember, in 1939 and 1940 the RAF conducted some daylight bombing raids over Germany, just small formations of their bombers (Blenheims and Wellingtons), and took catastrophic losses (i.e. December 1939) at the hands of the Luftwaffe.

The RAF had endured the experience of daylight bombing when unescorted small bomber formations faced the Luftwaffe. Yes, such RAF bombers (1939 and 1940) did not carry the number of defensive machine guns those of the USAAF did from 1943 and on; but they learned the lesson and knew daylight bombing unescorted missions were extremely dangerous, switching thus to night missions.

It appears to me, after all, the theory of the Luftwaffe to send big fleets of bombers to bomb England, even if it failed, had more coherence and had a certain level of combat background (Spanish civil war).

Unlike the Luftwaffe, the USAAF went on to put into practice an experiment which proved a failure. We now know the outcome of such experiment: dozens of thousands of airmen simply took off to never be seen again.

While I agree when you say many speak only on how massive the defensive armament of the USAAF heavies was and also how effective they were at shooting down German fighters (which most of the times were not shot down, at all), the RAF effort has been certainly remained in a lower profile.

[Medvedya]

Originally Posted by Udet

Ok sods, go ahead and have a lovely flight" and simply said: "Ok Sir, in view of your insisting and since you are our guests, we, the RAF, will have to take the night shift."

Shhhhh! You know far, far, too much about us!

[Tony Williams]

There was a fundamental difference in the requirements for day and night bombing. The day bombers needed their heavy defensive armament (if only for the morale of the crew!) but the night bombers would have been better off without it. All they needed was people to keep a good lookout for the night fighters, as once spotted the bombers' best chance of escape was to take violent evasive action and hope to 'lose' the fighter.

Tony Williams: Military gun and ammunition website and Discussion forum

Gunnery was difficult for fighter pilots. It was nearly impossible for bomber gunners.

The defensive guns of planes like the B-17 did force the enemy to modify their tactics. A fighter could not just sit behind a bomber box and pick off the targets at will. But this could have been accomplished with perhaps just the turrets and tail positions, the other guns were relatively ineffective (until the chin turret came into play).

Had the B-17's had the gun system of the B-29, they might have been more effective in defending themselves. The computerized gunsights and firing system meant that hitting fighters, even when making relatively fast approaches, would be much more likely.

But in the end it's simply a matter of cost. A single fighter, costing under $100,000 (in WWII $) with a crew of one could reasonably be expected to kill a $600,000+ bomber with a crew of ten more often than it got killed itself. Given this fact, the idea of gunners defending the bombers was totally unrealistic. However, in combination with escort fighters, which made proper setup for attacking the bombers very difficult, the gunners were somewhat effective in protecting themselves. Without both escorts and gunners the bombers would have been much more vulnerable. On the other hand, faster bombers with only a tail gunner might have been even more successful.

=S=

Lunatic

[the lancaster kicks ass]

but the night bombers would have been better off without it. All they needed was people to keep a good lookout for the night fighters, as once spotted the bombers' best chance of escape was to take violent evasive action and hope to 'lose' the fighter.

that's a fair point and i agree largely, however the defensive armourment was still nessisary, 9/10 if an attacking night fighter pilot knew he had been spotted and the bomber was doing something about it (firing on him/taking evasive action) he would find another target, as such the armourment was important if only to scare off the fighters..............

[Udet]

Tony Williams¿?

He makes a very good point when saying perhaps an implicit element in the massive defensive armament of the USAAF heavies was the morale boosting one. To make them crews feel they had a "powerful" tool to defend themselves from interceptors.

Why is it you think the RAF heavy bombers would have fared better without defensive armament?

The Avro Lancaster was not capable of taking violent evasive action if spotting a German Ju88, Bf110 or He219 nightfighter homing in for the attack.

Even after releasing their bombs, the Lanc MkI is heavier than the B-17 and the maximun speed of both models is almost the same.

[the lancaster kicks ass]

The Avro Lancaster was not capable of taking violent evasive action if spotting a German Ju88, Bf110 or He219 nightfighter homing in for the attack.

Even after releasing their bombs, the Lanc MkI is heavier than the B-17 and the maximun speed of both models is almost the same.

the lancaster was EXTREMELY manouverable for a plane of it's size, it was extremely capable of violent evasive action, even by day the best fighter pilots would struggle to get a good aim on a corkscrewing lancaster....................

the maximun speed of both models is almost the same.

their top speed was the same, and bombers never flew at maximum, the cruising speed of the lanc was 28mph faster than that of the B-17, and speed means nothing in a Bomber-fighter encounter............

[cheddar cheese]

I think a Zero would do it easily

[Udet]

Lan Kick Ass:

The thread swiftly begins switching to off-topic playgrounds.

When I remarked upon the speed of both the B-17 and the Lancaster, I did so in order to put a minimun reference on their specifications, and not to give that sole element full value for the outcome in combat action.

Well, I do not doubt the Avro Lancaster, for heavy bomber standards, had a good level of maneuverability, since all aircraft have either a higher or lesser level of it. But against the 2 engine night fighters?

A big four engine heavy bomber with a crew of 7 and an empty weight about 10 times that of most Luftwaffe interceptors, does not stand much of a chance in outmaneuvering the twin engine Ju88Gs or Bf110s.

The Ju88 as a medium bomber during the Battle of Britain was strikingly fast and maneuverable once its bombload had been delivered and indeed surprised many Hurricane and Spitfire pilots with its ability to turn and accelerate: With this I am just telling the Ju88 as bomber, was a tough cookie for RAF interceptors in 1940, and not superior in terms of speed and maneuverability, ok?

If I recall correctly it was the German bomber with the lowest casualty rate during the BoB. Try to think of it as pure fighter during the night bombing missions of the RAF pursuing the Lancs.

[the lancaster kicks ass]

A big four engine heavy bomber with a crew of 7 and an empty weight about 10 times that of most Luftwaffe interceptors, does not stand much of a chance in outmaneuvering the twin engine Ju88Gs or Bf110s.

ah, you interpreted what i said to mean "the lanc could out manouver an attacking fighter" which, if you read my post again, you'll find i never said, i said

the best fighter pilots would struggle to get a good aim on a corkscrewing lancaster

that means that they, literally wouldn't be able to keep their aim on the lanc for long enough because it was being thrown around too violently, and it worked extremely well, there was absolutely no way to counter it and it saved thousands of lives

I think a Zero would do it easily

no it couldn't for the same reason as above, it wouldn't be able to keep it's aim for long enough...................

[BombTaxi]

To echo a point already made, the aim of the USAAF's 'Combat Box' was not to ensure the accuracy of individual gunners when engaging German interceptors. Like the box barrage used by German flak batteries, and by every surface fleet of WW2, it was designed to ensure the maximum amount of lead in the air during an inteceptors pass, hopefully crippling it. IMHO, the mistake of the USAAF was in underestimating the power of contemporary fighter armament. Against six- or eight gun fighters, such as the USAAF used, the Combat Box may well have succeeded, as each fighter would need to make a number of passes to destroy a B-17 sized target. However, cannon-armed LW fighter, especially the Fw190, were capable of destroying or seriously damaging a heavy bomber in one short pass, thereby negating the Combat Box principle.

German bombers suffered defensively largely as a result of faulty design philosophy. The idea of concentrating the crew in a small, glazed nose compartment, in order to preserve morale, simply made the crew more vulnerable to being eliminated in a single pass, and also limited the arc of defensive MG's, especially on aircraft like the Ju88 and the Dornier bombers. Had the designs allowed for a greater distribution of weapons as as seen on the later He11s and on allied heavy bombers, the LW medium bombers might have fared better defensively.
Furthermore, the LW made a similar mistake to the USAAF in underestimating the power of its enemies. When the medium bomber designs were formulated aroud the Spanish Civil War, the fighters then available to European airforces were inferior inperformance to the LW mediums. The RAF and Regia Aeronautica were still flying biplanes, with some monoplanes appearing, while the VVS and Armee d' Air (excuse my poor French! ) were using first-generation monoplanes like the I-16, which did not compare favourably to the latest German designs. So in 1936-8, the German bomber philosophy was well-founded; however, the introduction of fast monoplanes, especially the Spitfire and Hurricane in the post-Munich era, invalidated both the bomber philosophy, and the Zerstorer philosophy that acommpanied it.

[the lancaster kicks ass]

all very valid and interesting points, you sound like you know what you're talking about...................