The Bf 109B was the first version of this famous fighter to enter mass production. The Bf 109 was designed to meet the requirements of a specification for the “Armed Aircraft IV”. At a time when the main Luftwaffe fighters were still biplanes, this specification called for a low-wing all-metal monoplane with retractable undercarriage, a very advanced design. The “Armed Aircraft IV” specifications were drawn up in December 1933, and issued to three aircraft manufacturers in February 1934. Arado and Heinkel were established producers of Luftwaffe fighters. Messerschmitt was very much the outsider in the contest. His company, the Bayerische Flugzeugwerke (thus the Bf), had a poor relationship with the Luftwaffe high command, and in the major rearmament drive after the Nazis came to power had only been given one contract, to build twelve Heinkel He 45s.
Willy Messerschmitt came up with the most advanced design. He created a all-metal stress-skin aircraft, with a fully enclosed cockpit (unlike the partly open cockpits on the Arado and Heinkel planes. The fuselage was the narrowest that could take the two most powerful aircraft engines then under development in Germany – the Junkers Jumo 210 and the Daimler Benz DB 600 (although the second engine would not enter mainstream service until the appearance of the Bf 109E). Basic test models were ready by October 1934. By mid-1935 the first prototype was ready to receive its engine. This aircraft, Bf 109V-1 had to use a Rolls-Royce Kestrel V 12-cylinder engine, after problems with the development of the two German engines. This was a 695 hp engine, slightly more powerful than the Jumo 210A used in the second and third prototypes (V-2 and V-3), which provided 610 hp. The Bf 109 V-1 took to the skies in September 1935.
The Bf 109 V-1 was flown to the Luftwaffe testing ground at Rechlin in October and then on to the trail ground at Travemünde in the same month. The V-2 joined it in February 1936 (crashing in April), and the V-3 in June.
The first of the serious competitors to drop out of the contest was the Arado Ar 80. This aircraft had suffered from delays in development, especially with the retractable undercarriage, and entered the first comparative tests with a fixed undercarriage. This reduced its maximum speed and overall performance to the extent that Arado withdrew it from the contest. A second competitor was also soon disposed of. Focke-Wolf entered the fray late, with the Fw 159, a high-winged monoplane which could not compete with the He 112 or the Bf 109.
When the tests began the He 112 was the favourite to win the contest. It was initially more popular with the Luftwaffe test pilots, but at extended tests in February-March 1936 the Bf 109 V-2 proved itself to be the superior fighter. Heinkel made great efforts to improve their aircraft, but were unable to catch up in time. After these first tests, the Luftwaffe placed orders for ten pre-production models of both aircraft.
The final fly-off between the two aircraft came in November 1936 at Travemünde. Here the Bf 109 performed a sequence of 23 left hand spins then 21 right hand spins followed by a dive from 23,000 feet. The Heinkel was unable to repeat this performance. It was also now clear that the Bf 109 was considerably cheaper to build, and so Messerschmitt was awarded the contract to construct the Luftwaffe’s new front-line fighter aircraft.
Even before the contract was awarded, the Luftwaffe’s requirements had changed. In the original plans the Bf 109A had been armed with two MG 17 machine guns. By the end of 1936 rumours were reaching Germany about the new British fighters – the Hurricane and the Spitfire. It was clear that these new fighters would out-gun the Bf 109A. The specifications were according adjusted to include a third machine gun, firing through the engine, which was to be replaced by a 20 mm MG FF cannon. This engine mounted gun was to be repeated in several early versions of the Bf109, and was never popular with pilots, suffering from overheating and vibration problems inevitable from its position inside the engine.
Four prototype 109Bs followed. V-4 appeared in November 1936, V-5 and V-6 followed in December and V-8 early in 1937. By that time, the previous four prototypes had been spent to Spain for combat evaluation. The production Bf109 B-1 appeared in the spring of 1937. In April some of the early models were sent to Spain to reinforce the Legion Condor, whose biplane fighters were rapidly becoming obsolete. A second variant, the B-2, soon followed, before the Bf109 C entered production in September 1937.
Bf 109 B-1
The B-1 was powered by the Jumo 210D engine. This engine gave 720 hp at take off, and 650 hp in continuous flight, giving the B-1 a maximum speed of 470kph/ 292 mph at 13,120 feet. It had a wooden fixed pitch propeller, and was armed with two 7.9 mm MG 17 machine guns, located over the engine cowling. These guns had to be manually cocked by the pilot between bursts of firing. Just under 30 B-1s were made, before production switched the B-2 variant.
Bf 109 B-2
The B-2 differed mainly from the B-1 in having a third MG 17 mounted in the engine, firing through the propeller hub, and in having a Hamilton two-blade variable pitch metal airscrew. This third gun was prone to overheat and jam, as it was very hard to provide adequate cooling in the cramped confines of the space between the engine cylinder banks. The metal propeller was also often added the B-1s to improve their performance. Later models had the slightly more powerful Jumo 210 Da engine.
Max speed 465 km/h (298 mph); Jumo 210 600hp?
The young Luftwaffe gained valuable combat experience during the Spanish Civil War. At first German support for Franco was carried out as secretly as possible, but on 7 November 1936 that support was made public with the official creation of the Legion Condor. At its peak, the Legion Condor included twelve staffeln (squadrons) of aircraft, including three (sometimes rising to four) fighter staffeln (1.J/88 to 4.J/88) and an experimental fighter staffel (VJ/88). This force was initially equipped with the Heinkel He-51 biplane fighter, and had won some easy victories against markedly inferior opponents. However, by the end of 1936 the He-51 was outclassed by both the Polikarpow I-15 “Chato” (sometimes called the “Curtiss”), itself a biplane, and the I-16 “Rata”.
In December 1936 four of the prototype Bf 109s (V.3, V.4, V.5 and V.6) were sent to Spain, for evaluation by VJ/88 (the He 112 V3 was also sent). The V.4 was destroyed while taking off on 10 December, but the remaining prototypes proved their worth.
Production model Bf 109B-1s soon began to appear in Spain. The first three arrived on 14 March 1937, and were allocated to 2.J/88. The Bf 109B scored its first combat victory in 6 April 1937, when Oblt. Günther Lützow shot down an I-15. In all 41 109Bs were shipped to Spain (14 B-1s and 27 B-2s). When the Bf 109B-2 reached Spain, it proved to be the equal of the I-16, and superior to every other Republican plane.
However, this was a period of rapid aircraft development. By the end of 1937 the Bf 109B-2 was outclassed by the I-16 Type 10, which could out-climb, out-turn and out-gun the Messerschmitt. By the summer of 1938, the Legion Condor was starting to run out of aircraft – 1.J/88 was down to four 109s while 2.J/88 and seven. Only five Bf 109Cs were sent to Spain, and the 109Bs had to fight on until the end of June 1938, when the first 109Ds began to appear.
The Spanish experience played a crucial role in the development of the Bf 109. The 109B was not the equal of its British contemporaries – the Hurricane I and Spitfire I. Even with the extra machine gun added to the original design, it proved to be distinctly under-gunned. Later models were significantly more heavily armed. The undercarriage also proved to be a weakness, both because it was prone to collapse under stress, and because pilots used to fixed undercarriages sometimes forgot to lower it! Accidents while landing or taking off destroyed around 5% of all Bf 109s built, causing around 1,600 losses. The Bf 109 also had a very short operational range. Even during the Battle of France this was to cause problems when the speed of the German advance left the Luftwaffe airfields too far to the rear, and it was to be a serious weakness during the Battle of Britain. Despite these weaknesses, the basic design of the Bf 109 was sound, and with more powerful engines and weapons it continued to be a potent force for most of the second world war.