The Combined Bomber Offensive 1943 - 1944: The Air Attack on Nazi Germany. L. Douglas Keeney
over hand-held guns in field of fire, accuracy, and fire power per gunner. Since the chin turret was not expected until late in 1943, another temporary experiment in the form of a reworked Bendix lower turret was tried out during the first phase. An airplane with one of these experimental turrets arrived in the theater on 27 June and was given thorough tests. The preliminary results indicated some superiority over the hand-held guns, but combat tests proved the later better. The reworked turret would not react quickly enough on simultaneous attacks from several directions. Orders were given from Headquarters, AAF to stop installation of the makeshift lower turret and to continue with the development of the regular chin turret. Meanwhile it should be remembered that the chief dependence for forward fire cover by heavy bombers during the first phase was upon the hand-held .50caliber gun provides with direct sighting. Other armament modifications were performed on the heavier but those designed to increase forward fire power seen most significant.
Coupled closely with the effort to increase the firepower of the bomb-carrying heavies was the attempt to convert a member to an escort cruiser by substituting fire power and armor for bomb-carrying capacity. In the spring of 1942, Maj. Gen. Carl A. Spaatz had speculated on the possibilities of such an aircraft: “Auxiliary (expendable) tanks offer the only immediate solution for extending the range of fighters, unless it can be developed that the bomber, with its fire-mover, can substitute ammunition for bomb-load and act as an accompanying fighter. The escort cruiser which was developed – a heavily armed and armored B-17 – was designated the XB-40. This craft had the chin turret, upper turret, ball turret, direct-sighting power-boosted twin .50’s on each side of the waist, twin .50’s in a Martin electric upper turret in the radio compartment, and twin .50’s in a power-boosted tail gun mount with reflector sights. It carried 40,000 rounds of ammunition. General Eaker was quite interested in the development and in mid-March 1943 expressed a desire to try it out against the Germans, but at the same time voiced doubt about the economy of taking bombers that did not carry bombs on combat missions. In the operating groups there was more enthusiasm for the escort airplane, particularly for the chin turret which was one of its most promising features.
In mid-April, when the German fighters were concentrating on the lead formations of his bomber forces, the Eighth’s commander became very anxious to get some of the YB-40’s as quickly as possible. He was told that 13 YB-40’s were to be sent to the United Kingdom just as soon as the crews had completed their gunnery training.
These heavy cruisers arrived in the theater in the first part of May and most of them were assigned to the 92d Bomb Group (II). After additional training and modification they embarked on their first mission on 29 May, when seven were dispatched to St. Nazaire. The initial dictated the necessity for modification of waist and experience tail gun feeds and ammunition supplies, and indicated the basic defect of the craft, which was its inability to keep up with normal B-17’s – especially after the latter had dropped their bombs. Modifications were complete by 15 June, and YB-40’s took part in five missions during the last half of the month. On the 22 June raid on Huls, 11 were dispatched and one was lost. On the 25th, only four of the seven dispatched were able to accompany the formations to Northwest Germany. Five took off on the 26th, but not one was able to complete the attack. Their record was better against St. Nazaire on the 23th, when all six dispatched completed the mission. The mission to Le Mans on 28 June found the two that were dispatched abortive.
Although the YB-40’s were to see further action in the theater, the June experience was sufficient for the Eighth’s commander to form an adverse judgment on this version of the escort cruiser. His report condemned it because it had different flight characteristics (it was tail-heavy) and was so much heavier than the normal B-17 that it could not fly formation with them. And 40’s had been tried in their own formations and on either side of the lead ship in a combat wing, but in neither case were they successful. The crews of the YB-40’s did not like the planes because they had to occupy the hot spots in the formation and because they carried no bombs. General Eaker was strongly sold on one feature of the YB-40 – the chin turret – which was presently to be placed on all operating heavies. He did not entirely condemn the whole idea of such an escort, but the June experience convinced him that such a craft required two features that the 40’s did not have: the ability to carry bombs and the same flight characteristics as other bombers.
At the same time that the development of the heavy escort was taking place, attention was given to the build-up of a fighter force and the extension of the range of our fighter craft for escort purposes.
The fighter situation in the Eighth Air Force during the first quarter of 1943 was pitiful. It has been noticed that three P-38-equipped groups had been sent from the Eighth to the Twelfth Air Force in October 1942. Four additional fighter groups were trained by the Eighth for the North African theater during the last part of 1942. There was but one operational group left to the Eighth and that was the 4th (“Eagle”) Fighter Group, equipped with Spitfires. This situation prevailed until 3 April 1943, when three groups became operational. These three (4th, 76th, and 56th) were all using the P-47 Thunderbolt at the time. The 4th first had had some P-47’s assigned to it in January, and was converted to this craft in March. The 78th camp to the theater equipped with P-38’s but was presently reequipped with the P-47. The 56th came to the United Kingdom on 13 January 1943, already out-fitted with the Thunderbolt. The tardiness in getting the P-47 into operation was due partly to radio and mechanical difficulties in the aircraft and to the necessity for “selling” it to the pilots. Moreover, the Fighter Command had to proceed cautiously, for it did not want to run the risk of a serious setback in making a new airplane operational.
Three operational groups of fighters were all the Eighth had during the first phase of the bomber offensive. Although the 353d Group arrived in the theater in June, it did not become operational until August.
Inquiry as to why VIII Fighter Command was no better off in the early part of 1943 is not very profitable. Inter-theater competition drained the groups away and there seems to have been some weight of opinion that the B-17 could carry out daylight operations without escort. The CBO Plan had provided no build-up rate for fighters as it had for bombers, although it had called attention to the need for the latter craft. General Bradley, chief author of the build-up and troop basis for the Eighth, had made the assumption that strategic bombing would generally be unsupported by fighters because of the fighters’ deficiency of range. Whatever the reason, VIII Fighter Command was sadly lacking in planes all during the first phase.
The realization that they were needed, however, became strongly impressed upon the minds of the air force leaders on both sides of the Atlantic. The attrition and damage figures were easy to read. In April the Commanding General of VIII Fighter Command expressed the need for 30 groups and the opinion that opposition to the bomber offensive would grow heavier unless the German fighters were neutralized by an American fighter force. The German fighter tactics of concentrating against the bombers during the bombing run made it clear that protection would have to go all the way to the target. This was set forth by Assistant Secretary of war for Air Robert A. Lovett after a trip to the United Kingdom in June. He declared, “The greatest single factor differentiating the 8th AF operations from those in other theaters is the extremely high proportion of battle damage resulting from combat with the best German fighters … . There is an immediate need for long range fighters. This may be met by tanks for the P-47s for now but ultimately P-38s and P-51s will be needed.”
The story of increasing fighter range by use of drop tanks is well covered in the histories of VIII Fighter Command and VIII Air Force Service Command. Here all that is necessary is to note the progress that was made in this development during the first phase of the bomber offensive. Expendable tanks were not a development of the European theater, but had been used for some time for ferrying purposes. One of the first tanks used by the P-47 was a 200-gallon-capacity paper ferry tank. The tests which were made on this tank in March 1943 were only partially satisfactory because fuel could not be extracted above 20,000 feet. Moreover, its structure was much that it was not capable of pressurization, and it was not good aerodynamically. However, the range of the Thunderbolt could be extended by using fuel from this tank while climbing to altitude. Such tanks were employed on the first escort mission in which VIII Fighter Command used droppable tanks.