...daylight bombers:
The 8th AF
In July 1942 the first aircraft of the 8th Army Air Force arrived in Britain. Initially the American commanders restricted themselves to cautious attacks on targets within the range of the available escort fighters, but soon they ventured beyond the range of the escort fighters. On 27 January 1943 a target in Germany was attacked for the first time: 91 heavy bombers attacked Wilhelmshaven and Emden.
All precedents indicated that unescorted daylight attacks would result in heavy losses of bombers, but the leaders of the 8th AAF nevertheless adopted this as a tactic. They believed that only daylight attacks could have the precision needed to take out the German war industry. Day bombardments, Ira Eaker argued, were five times as accurate as night bombardments; and in 1943 this was probably true. Only later in the war, when better navigation aids became available and marking techniques were improved, did night bombardments rival the accuracy of day bombardments. Besides, the 8th AAF was a day bombing force, and switching to night attack would have required a complete reorganisation, re-training and re-equipment.
The answer to the fighter treat, it was believed, was to have more and heavier guns per bomber, attacks by fleets of 300 or more bombers, and close-packed formations that were carefully arranged to give each gunner the best possible field of fire. The "combat boxes" would be able to bring more firepower to bear on the enemy fighters than any bomber formation had ever done before.
Only small men would fit in the ball turret of a B-17. Although uncomfortable, this was a much more effective defense than remote-controlled weapons with periscopic gunsights, and it caused less drag than a "dustbin" turret. [32]
The Boeing B-17 Flying Fortress and Consolidated B-24 Liberator certainly were heavily armed. In the first versions, the armament of the "Flying Fortress" had consisted of only five manually operated machineguns, an arrangement that invoked sharp criticism from the British, who considered the aircraft "practically indefensible against any modern fighter."[34] But when the 8th AF began operations, the US heavy bomber had been redesigned, taking into account the combat reports from Europe. They had dorsal turrets and ventral "ball" turrets with two Browning .50 M2 machineguns. A tail gunner controlled two more .50s. Two windows in the waist of the aircraft each accomodated a single .50 gun. In the B-17 another single .50 was fired from the radio room. Of course all this armament was rather heavy, to a total of over 2580 kg (5700 lb),[66] and that was more than the bombload on long-range missions. In principle this gave them excellent defensive firepower in the entire rear hemisphere. Optimists declared that it meant "almost certain death" for any enemy fighter to approach a Flying Fortress.[67]
The front was a weak point, however. Although the prototype had had a nose turret, the frontal defense of the production B-17 was limited to a number of manually aimed machineguns, initially a single .30 machinegun; it was soon replaced by a .50, and one or two more .50s were installed in small "cheek" windows. The B-24 had similar armament. This was not enough, because the Germans soon understood that the B-17 was really vulnerable to frontal attack. Not only was the forward firepower limited, there was no armour to protect the crew from such attacks. The German pilot Anton Hackl commented:[11]
One accurate half-second burst from head-on and a kill was guaranteed. Guaranteed!
The Germans concluded that in a head-on attack, four or five 20mm hits would destroy a bomber, while it usually required more than 20 hits when attacking from another angle. Of course the head-on attacks were difficult to set up, and required very experienced pilots. But clearly something had to be done. The cockpit windows were soon replaced by laminated armoured glass,[65] and the nose armament was increased. At first units in the field improvised more powerful nose armament, but the B-17G and B-24H introduced powered nose turrets with two .50s.
These nose turrets were a fortunate spin-off of new experiments with the "air cruiser" concept: The YB-40, a heavily armed "escort fighter" version of the B-17, and the XB-41, a similar version of the B-24. Only one prototype of the XB-41 was completed, but twenty-one YB-40s were created. Combat experience showed that the YB-40s with all their additional armament, armour and ammunition were too slow to maintain formation with the B-17s, and that ended the experiment.
The single XB-41. Note the two dorsal turrets and the chin turret, B-17G style. Waist gun positions were fitted with two power-operated guns each. This was not just a bad idea, the aircraft had poor flying characteristics as well. [32]
Even the best all-round armament was never enough. Deep penetrations in German territory turned out to be extremely costly. The most famous examples are the attacks on Regensburg and Schweinfurt: The first attack, on 17 August, resulted in the loss of 60 bombers out of a force of 363. Some consolation was found in the claims by the gunners, which amounted to a total of 228 enemy fighters shot down; even after careful evaluation of claims the 8th AF estimated the German losses to be between 148 and 100. In fact the Luftwaffe had lost only 25 fighters. A repeat attack on 14 October gave a confirmation, if any was necessary: 65 more B-17s were lost. The initial claim of enemy fighters downed was even higher than in the first attack, 288; but even the official figure of 104 was way above the real German loss: 35. (See Note 3.)
The infamous attacks on Schweinfurt were not unique. They were merely the most serious in a long series of disasters for the 8th AAF. In 1943, it was clearly losing the battle with the German fighter defenses.
Why did the heavy bombers fail? Apparently the leaders of the 8th AF simply underestimated the difficulty of the task the gunners faced. There were some skeptics, such as Col. Claude E. Putnam, the commander of the 306th BG, who estimated in 1943 that only 10% of the gunners who could theoretically have fired at an enemy aircraft really did so, and that at least four gunners needed to fire to have a 50% probability to shoot an enemy aircraft down. The commander of the 308th shared his doubts, wondering whether the guns were not more a hazard than a protection.[35]
The attacking fighters were small targets in an often confusing battle, and it was not at all evident that gunners would see them, identify them, estimate their distance and speed, aim correctly, and fire at the right time. This looked good on paper, but in practice it was an almost impossible task. During WWII, the hit probability for fixed, forward-firing guns was estimated to be only about 2% for an average pilot; and the operation of flexible guns is far more complex. The German fighter pilots flew short missions; the gunners spent long hours in cold, draughty, and incredibly noisy aircraft, shaking in the turbulence created by the large bomber formations. The gunsights were often primitive: The powered turrets had some form of computing sight, but most hand-aimed guns had simple ring-and-bead sights. The field of view and fire from some positions, notably the radio room of the B-17 and the waist positions, was quite limited. Overall, the German fighters held a clear advantage.
Another factor was that the gunners were not trained well enough.[27] After the outbreak of war a large training program was created, but there was little experience in the field, little equipment, and it was very difficult to find and retain competent instructors. During the war some improvements were made, but as late as 1944 a War Department report admitted that some gunners simply didn't know how to operate their gun turrets! Operational units had priority for equipment, and gunnery training was sadly neglected: It was mid-1944 before enough aircraft were made available to gunnery schools and gun cameras became available for training purposes.
The assumption that the concentrated fire of a "combat box" would fend off fighters also had a fundamental flaw: It ignored that the fighters would react by concentrating their attacks. Initially the Luftwaffe went after the lower groups, but later it often attacked the lead group, because they knew that it contained the lead bombardier. The formation did offer significant protection to the bombers; indeed any bomber that left the formation became an easy kill. But it was not enough.
The exaggerated kill claims gave a false impression of the effectiveness of the defensive guns, and for this reason the 8th AF continued unescorted daylight attacks for far too long. The usual reason given for the excessively high claims is that any German aircraft shot down was claimed by multiple gunners, who had all fired in its direction. In addition, too often any puff of smoke from a German aircraft was interpreted as a sign of a fatal hit, while it often enough just indicated a rough handling of the throttle. The gunners had to do an impossible job in extremely dangerous conditions, and can hardly be blamed for compiling incorrect statistics.
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