The Battle of Britain (15 page)

As it became increasingly obvious that the more sanguine predictions for DB 601A engine delivery could not be met, the decision was taken to build an interim model, the Bf 110B with direct-fuel-injection two-stage supercharged Jumo 210Ga engines. While it was considered that the Bf 110B would possess an inadequate performance for combat purposes, it was seen as an ideal tool for equipment and armament evaluation, and the development of operational techniques. It was accordingly issued during late 1938 to I (Schweren Jagdgruppe)/LG 1 of the so-called Luftwaffe Lehrdivision, or Instructional Division, whose task was that of formulating tactics and techniques. In January 1939, this Gruppe was to become I(Z)/LG 1 when the title schwere Jagd was abandoned in favour of that of Zerstörer.

With the DB 601A engine, the Messerschmitt Zerstörer became the Bf 110C, a pre-series of 10 being delivered to the Luftwaffe early in January 1939, and acceptances of the initial production Bf 110C-1 by I(Z)/LG 1 began before the end of that month. Production of the Bf 110C-1 gathered momentum rapidly owing to the high priority that it enjoyed, and by the early summer of 1939, Focke-Wulf and the Gothaer Waggonfabrik had tooled up to supplement the output of Messerschmitt's Augsburg-Haunstetten factory, and MIAG at Braunschweig was preparing to phase into the programme.

By August 31, 1939, a total of 159 Bf 110C fighters had been accepted, although the Quartermaster-General's strength returns for that date indicated that only 68 of these, plus 27 Bf 110Bs, had actually been taken into the inventory. Two Zerstörergruppen, I/ZG 1 and I/ZG 76, had meanwhile been working up on the new warplane, and these, together with I(Z)/LG 1, were to be included in the Order of Battle against Poland.

Output of the Bf 110C had risen to more than 30 per month, and a further 156 were to be delivered during the first four months of hostilities when tempo was progressively rising – the average monthly production during 1940 was to be 102.6 aircraft – and the Zerstörer element of the Luftwaffe expanding commensurately. Powered by two DB 601A-1 12-cylinder
inverted-vee engines each rated at 1,050hp for take-off, the Bf 110C-1 carried an armament of two 20mm MG FF cannon each with 180 rounds, four fixed forward-firing 7.9mm MG 17 machine guns each with 1,000 rounds and a flexibly-mounted aft-firing MG 15 with 750 rounds. With maximum speeds ranging from 295mph (475km/h) at sea level to 336mph (540km/h) at 19,685ft (6,000m), and a high-speed cruise of 262mph (422km/h) at sea level and 304mph (490km/h) at 16,400ft (5,000m), performance compared favourably in these respects with the best single-seat fighters extant.

Normal maximum range at economic cruise of 217mph (350km/h) at 13,780ft (4,200m) was 680 miles (1,095km), but the introduction of auxiliary tanks in the wing outboard of the engine nacelles raised internal fuel capacity by a further 121 Imp gal (550 litres) to increase maximum range to 876 miles (1,410km).

Early operational experience had resulted in the successive introduction of the Bf 110C-2, differing solely in having FuG 10 HF radio in place of the original FuG 3aU R/T and the Bf 110C-3 which differed in having improved MG FF cannon. These now gave place to the Bf 110C-4 in which, for the first time, some attempt was made to provide at least nominal armour protection for pilot and gunner, normal loaded weight rising some 490lb (222kg) over that of the Bf 110C-1 to 13,779lb (6,250kg). Further escalation in weight resulted from a demand for adaptation of the aircraft for the Jagd-bomber (Jabo) mission, two EM 250 racks being introduced beneath the fuselage centre section for a pair of 551lb (250kg) bombs.

The substantially increased overload weight necessitated more power for take-off and emergency use, and thus the Jabo model, the Bf 110C-4/B, was fitted with DB 601N engines which, with increased compression and 96 Octane fuel, had a maximum take-off output of 1,200hp with full boost for one minute. Issued to the Erprobungsgruppe 210, the Bf 110C-4/B fighter-bombers of two staffeln of this unit were to operate throughout the ensuing Battle singly and in small groups, and taking maximum advantage of the element of surprise by using terrain-following tactics.

A parallel development was the Bf 110C-5 which had a single Rb 50/30 reconnaissance camera in the cockpit floor, forward-firing armament being restricted to the quartet of machine guns. This sub-type was to reach the Aufklärungstaffeln, or reconnaissance squadrons, in time to
participate in the Battle, initially in mixed units with the Do 17P and Do 17Z.

On July 20, 1940, a total of 278 Bf 110s was available to Luftflotten 2, 3 and 5, and of these 200 were serviceable. Overall strength of the Zerstörergruppen that were to participate in the assault on the United Kingdom was virtually unchanged on August 13, Adler Tag, comprising 289 aircraft of which 224 were serviceable. Apart from the langstrecken Zerstörergruppen I/ZG 76 and V(Z)/LG 1 with Bf 110C-4s and D-1s*, and 1. and 2. Staffeln of E.Gr.210 with Bf 110C-4/Bs, the principal Bf 110-equipped units committed to the Battle were the Stab and I and II/ZG 2, the Stab and I, II and III/ZG 26, and II and III/ZG 76.

Theoretically, with their superior endurance, the Bf 110s were to entice the RAF fighter squadrons into combat. The bomber squadrons would then follow at a suitable distance, arriving when the defending fighters had exhausted their fuel and were thus powerless to intervene. Furthermore, it was anticipated that the RAF fighters, sitting on their bases rearming and refuelling, would be extremely vulnerable and would afford excellent targets for the bombers and the additional Bf 110s escorting them.

This theory was to prove fallacious from the outset. To the chagrin of the Zerstörergruppen, the capabilities of their mounts fell far short of their expectations. The flying characteristics of the Bf 110 were very pleasant; its controls were fairly light, well harmonised and very effective up to 250mph (402km/h), although they began to heavy up above this speed. Stability was good fore and aft and directionally, but neutral laterally, and manoeuvrability was very good for so large an aeroplane. It was sluggish by comparison with the manoeuvrability of the Hurricane and Spitfire, however, and a serious fault was provided by the wing leading-edge slots which kept popping open in tight turns, gun sighting being ruined by the resultant lateral wobble.

While the forward-firing armament was undeniably lethal, it was difficult to bring to bear on the Bf 110's more agile opponents and the single 7.9mm MG 15 wielded by the radio operator/gunner in the rear cockpit afforded little protection against attack from astern. The acceleration and speed of the Bf 110 were insufficient to enable its pilot to avoid combat when opposed by superior numbers of interceptors, and as soon as RAF Fighter Command had taken the measure of the Messerschmitt Zerstörer, the Bf 110-equipped Gruppen began to suffer frightful operational attrition.
During August alone a total of 120 Bf 110s was lost on operations, the preponderance of them after Adler Tag. Thus, within less than three weeks, the Zerstörergruppen lost some 40 per cent of the aircraft on strength when the assault began.

It was patently obvious that the Bf 110 should have been withdrawn from the aerial offensive, but an overall shortage of Bf 109Es, coupled with their inadequate range, necessitated retention of the Messerschmitt Zerstörer. Incapable of defending the bombers that it was intended to escort, the Bf 110 was hard put to defend itself and its losses were out of all proportion to its achievements. Despite a substantial reduction in sorties and changes in tactics, the Zerstörergruppen had lost a further 83 aircraft by the end of September, their presence in the area providing a defensive liability for the overstretched Bf 109E units.

The catastrophic losses had already dictated the disbandment of some Gruppen, including I and II/ZG 2, and the folly of pitting the Bf 110 against a determined force of single-seat fighters was finally accepted by the Oberkommando der Luftwaffe, which, throughout the final weeks of the Battle confined the Messerschmitt twin to the fighter-bomber and reconnaissance tasks. Reichsmarschall Goering's boastful claims for his élite Zerstörergruppen had been proved singularly hollow.

No warplane possessed greater réclame in the opening months of World War II than the Junkers Ju 87 two-seat dive bomber, its notoriety assiduously propagated by German publicity. Indeed, the Polish and French campaigns in which it had participated had endowed the Ju 87 with a fearsome reputation as an outstandingly effective precision bombing instrument and a supremely effective ground strafer. With its banshee-like wail emitted as it hurtled vertically earthwards, it had a devastating psychological effect on the recipients of its attention. Synonymous with the sobriquet of Stuka – a derivation of Sturzkampfflugzeug, a term embracing all dive bombers – the Ju 87 was seen by the German High Command as a successor to long-range artillery, and first and foremost a tool for the direct support of ground forces.

Lacking all aesthetic pretentions, the Junkers dive bomber was an angularly ugly creation, but it was an extremely sturdy aircraft, offering its pilot light controls, pleasant flying characteristics and, for an aircraft of its size, a comparatively high standard of manoeuvrability. Its crew members
enjoyed good visibility and it was reputed to be capable of hitting its target with an accuracy of less than 100ft (30m). All very desirable though these characteristics were, successful operation of the Ju 87 presupposed a considerable measure of control in the air without which it became an anachronism, the natural prey of the fighter. Once the Ju 87 encountered determined fighter opposition, such as was to be found over the United Kingdom, its career dramatically entered its eclipse.

Like many German prototypes of the period, the Ju 87 began flight test with a British engine, a fully supercharged Kestrel V rated at 640hp at 14,000ft (4,267m). Flown at Dessau in the late spring of 1935 this, the Ju 87 V1, was to enjoy only a brief test career. During diving trials in the following summer, the entire tail assembly began to oscillate, the starboard element of its twin vertical tail surface breaking away when the pilot attempted to recover from his dive. This necessitated Dipl-Ing Herman Pohlmann and his design team, who had initiated work on the Ju 87 in 1933, undertaking hurried redesign of the tail surfaces, a new single fin-and-rudder assembly being applied to the second prototype, the Ju 87 V2, with which the flight test programme was resumed in the late autumn of 1935.

Unlike the first prototype, the Ju 87 V2 was powered by the intended Junkers Jumo 210Aa inverted-vee 12-cylinder engine for which the dive bomber had been designed, this being rated at 610hp at 8,530ft (2,600m). This aircraft was fitted with dive brakes prior to its delivery to the Rechlin test centre for official evaluation in March 1936. Attached beneath the wings just aft of the leading edges and outboard of the main undercarriage, these took the form of slats turning through 90deg. Prior to commencing the dive, the pilot had to throttle back the engine in order to close the cooling gills, switch over to the sea-level supercharger and turn the propeller to coarse pitch, a series of lines of inclination marked on the starboard front side screen of the cockpit enabling the pilot to estimate the dive angle by aligning the lines with the horizon.

Two more prototypes, the V3 and V4, offered various refinements, the latter introducing a single 7.9mm MG 17 machine gun in the starboard wing and a crutch on swing links which, attached immediately aft of the radiator bath, lowered and swung the bomb – either of 551lb or 1,102lb (250 or 500kg) – forward on release to ensure clearance of the propeller arc.

The first pre-series Ju 87A-0 dive bombers came off the Dessau assembly line before the end of 1936, 10 of these being followed by the
series Ju 87A-1 early in the following year. Late in 1937, three aircraft were detached from the I Gruppe of Stuka Geschwader 162 Immelmann and sent to Spain to evaluate dive bombing techniques under operational conditions. The Ju 87A-1 gave place to the A-2 with a Jumo 210Da engine affording 680hp for take-off late in 1937, but by that time a major redesign of the aircraft was in train to accommodate the Jumo 211A engine which offered 1,000hp for take-off.

The more powerful engine was installed in the pre-series Ju 87B-0, the Jumo 211A giving place in the series model, the Ju 87B-1, to the Jumo 211 Da with direct fuel injection and an emergency take-off rating of 1,200hp. The substantial boost in power enabled the Ju 87B-1 to lift a 1,102lb (500kg) bomb with both crew members
in situ
whereas the Ju 87A had only been able to carry this weapon when flown as a single-seater. An alternative warload consisted of a 551lb (250kg) bomb on the fuselage crutch and four 110lb (50kg) bombs on underwing racks. Forward-firing armament was increased to two 7.9mm MG 17s with 500rpg, and a single MG 15 machine gun of similar calibre was attached to a flexible mounting in the rear cockpit with 900 rounds,

Five of the first Ju 87B-1s were despatched to Spain in October 1938, these emulating the success enjoyed by the Ju 87As that had preceded them, and with the transfer of the assembly line from Dessau to the ‘Weser' Flugzeugbau at Berlin-Tempelhof, production tempo of the Junkers dive bomber increased dramatically, exceeding 60 aircraft monthly by mid-1939, in which year 557 were to be delivered. Nine Ju 87B-1-equipped Stukagruppen were to be included in the Luftwaffe Order of Battle on September 1, 1939, these possessing 336 aircraft of which 288 were serviceable.

Operating under ideal conditions, with negligible aerial opposition, the Stukagruppen had a devastating effect during the Polish campaign, serving primarily as a weapon for back-area bombing and exploiting to the full the accuracy of bomb aiming inherent in the steep diving attack. Only 31 Ju 87Bs were lost during Polish operations, or less than 10 per cent of the total Stuka force engaged; the legendary reputation that had been in the making in Spanish skies had now been firmly established in Polish skies and was to be consolidated seven months later over France.

The Ju 87B-2 had succeeded the B-l on the ‘Weser' assembly line late in 1939, this incorporating several refinements, such as a broad-bladed propeller, hydraulically-operated radiator cooling gills and ejector
exhausts. Manufactured in parallel was a longer-range version, the Ju 87R – the suffix letter indicating ‘Reichweite', or Range – which, for extended-range missions such as anti-shipping operations, made provision for substantial additional quantities of fuel and oil. Although there were some factions in the Luftwaffe that, because of the relative low speed and the vulnerability of the Ju 87, now considered this warplane to be approaching obsolescence, its successes in the Polish campaign boosted the influence of the pro-Stuka element and, far from phasing out, production was boosted, and a total of 769 was to be built during the course of 1940.