[1.0] First Generation Bf 109s

v2.0.8 / chapter 1 of 3 / 01 oct 17 / greg goebel

* The Bf 109 incorporated the latest aeronautical technologies when it was introduced in the mid-1930s -- but due to official resistance, there was still an element of luck in its adoption by the German Air Force, the Luftwaffe. However, even the initial variants of the Bf 109 proved impressive, and the type quickly matured to the excellent Bf 109E, which gave Hitler's Reich a great advantage in the opening rounds of World War II in Europe. This chapter describes the origins of the Bf 109 and its evolution up to the Bf 109E.

Messerschmitt Bf 109A versus Polikarpov I-16

[1.2] BF 109 ORIGINS
[1.4] BF 109E


* The path that led Willy Messerschmitt to the Bf 109 was a complicated one. Born in 1898, Messerschmitt formed his own company in March 1926, named the "Messerschmitt Flugzeugbau GMBH", with financial help from the Bavarian state government. However, the state government also had an interest in another aircraft firm named "Bayerische Flugzeugwerke (BFW / Bavarian Aircraft Company)". Unable to support both firms, the state government persuaded them to merge in September 1927, with Messerschmitt providing design and development expertise while BFW handled manufacturing. The company was established in Augsburg, Bavaria.

The first aircraft to be built by the new firm was an all-metal single-engine monoplane transport that could carry 8 passengers, designated the "M 20". The aircraft appeared very impressive, and the German state airline, Deutsche LuftHansa (DLH), ordered two. However, the M 20's development encountered delays, and when the prototype crashed during trials in February 1928, killing its pilot, the director of procurement of DLH, Erhard Milch, canceled the order. BFW built a second prototype in a hurry and put it through successful flight tests. The order was hesitantly reinstated, with LuftHansa requesting a batch of ten M 20s. Unfortunately, there were further crashes. The DLH canceled the order again, demanding repayment of advance funds.

Germany was in the grips of the global Depression at the time and BFW went bankrupt in June 1931. Fortunately, BFW's board of directors were sharp businessmen, and by 1933 BFW was back in operation again. However, the whole fiasco had led to bitter feuding between Messerschmitt and Milch. Since Milch had been given the post of Secretary of State for Aviation when Adolf Hitler came to power in 1932, prospects for contracts for BFW from the new Nazi government appeared slim.

To stay in business, Messerschmitt looked for work outside of Germany and landed two contracts from Rumania, including one for the "M 36" commercial transport, and one for the "M 37" trainer. Milch publicly denounced the transactions as treasonous; Gestapo secret police officers paid Messerschmitt and other BFW officials visits to investigate. Messerschmitt stood his ground, insisting that he had no choice: the German government refused to do business with BFW, and it was either export or go broke. Besides, if the Reich didn't want Messerschmitt aircraft, what reason was there to object to selling them to a friendly country like Rumania? Nothing more came of the investigations, possibly because Theo Croneiss, a high official of BFW, was a close friend of Minister of Aviation Hermann Goering, and in fact had been placed at BFW at Goering's request. It also appears that some German government officials were sympathetic to Messerschmitt's complaints of government indifference.

After a long streak of troubles, Messerschmitt and the BFW got a break in late 1933, when the German Air Ministry (Reichs Luftsfahrt Ministerium / RLM) decided that Germany should show off its capabilities in aviation by racing in the 4th "Challenge de Tourisme Internationale" air race, to be held in 1934. BFW and other German aircraft manufacturers were asked to develop air racers for the event. In fact, BFW had built a racer for the 1932 Challenge de Tourisme Internationale, but their "M 29" was disqualified from the race after two of the four machines built crashed. Unintimidated by this bad luck, Messerschmitt decided to build a new air racer, based on the M 37 trainer he was designing for the Rumanians.

The result was the "Bf 108A", which was first flown in February 1934. The Bf 108A was a two-seat low-wing monoplane with dual controls; a flush-riveted fuselage; retractable tailwheel landing gear with a tailskid; a Hirth HM 8V inverted-vee engine with 186 kW (250 HP), and a three-blade propeller. It could fly at 320 KPH (200 MPH) and was extremely agile. Five more prototypes followed. Then, on 27 July 1934, just before the race, the initial prototype crashed, killing its pilot. Messerschmitt and his staff worked frantically to ensure that the remaining five Bf 108As were qualified without mishaps.

The Bf 108A came in third in the competition. That was a bit disappointing, but the Bf 108A was clearly an excellent aircraft, and in fact as pilots got their hands on production machines, they started setting records with them. German aviatrix Elly Beinhorn flew one named "Taifun (Typhoon)" from Berlin to Constantinople in one day, and the BFW adopted the name for the aircraft.

The popularity of the Bf 108A Taifun led Messerschmitt to improve the design into a four-seat touring aircraft designated the "Bf 108B" that could also be used for military liaison and air ambulance roles. The Bf 108B featured an Argus As-8C inverted-vee piston engine with 180 kW (240 HP) in place of the Hirth engine, a proper tailwheel instead of a tailskid, and a two-blade fixed propeller.

Messerschmitt Bf 108 Taifun

The Bf 108B Taifun proved even more popular than the Bf 108A, with hundreds built.

   _____________________   _________________   _______________________
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                10.51 meters        34 feet 6 inches
   wing area               16.40 sq_meters     176.53 sq_feet
   length                  8.30 meters         27 feet 3 inches
   height                  2.3 meters          7 feet 7 inches

   empty weight            880 kilograms       1,940 pounds
   loaded weight           1,355 kilograms     2,990 pounds

   max speed at altitude   300 KPH             186 MPH / 162 KT
   service ceiling         6,000 meters        19,700 feet
   range                   1,000 kilometers    620 MI / 540 NMI
   _____________________   _________________   _______________________

A single "Bf 108C" using a Hirth HM 512 inverted-vee engine with 298 kW (400 HP) was built as a conversion of a stock Bf 108B, and two "208s" with tricycle landing gear were built by the French Societe Nationale de Constructions Aeronautiques du Nord during the German occupation. Nord also built stock Bf 108Bs during the war, and after the war the French firm continued the production of the type, with the Bf 108B sold as the Nord N.1000 "Pingouin (Penguin)" and the 208 as the "Nordalpha" and "Ramier (Woodpigeon)", powered by Renault 6Q or Potez 6 engines.

Interestingly, two Bf 108Bs used by the German embassy in Britain before the war were abandoned by the embassy staff on the outbreak of the conflict, and were impressed into British service as "hacks". They were called "Aldons" by their crews. The Bf 108B also served with the Luftwaffe as a liaison aircraft.


[1.2] BF 109 ORIGINS

* Messerschmitt and his colleagues were encouraged by the Bf 108, and decided they could compete in a competition for a new fighter for the Luftwaffe. The RLM specification had been issued in early 1934, and dictated a fast monoplane, armed with at least two MG 17 7.9-millimeter machine guns, and capable of being fitted with the new liquid-cooled inverted vee-12 engines being developed by Junkers and Daimler-Benz.

The request had been sent to other German aircraft manufacturers, including Focke-Wulf, Arado, and Heinkel, but Milch had blocked it from being sent to BFW. Lobbying by Theo Croneiss with his friend Hermann Goering, enthusiasm by a clique of Luftwaffe officers for the Bf 108A, and heavy demands on German aircraft production overcame Milch's hostility to Willy Messerschmitt, and in 1935 BFW was given a contract to participate in the fighter competition. Milch let it be known that as far as he was concerned there would be no follow-on production contract granted to BFW under any circumstances. Messerschmitt had to decide between going ahead with the fighter or taking a professorship at Danzig Technical University; having faith in his design and knowing that Milch expected him to fail, he decided to push on with the fighter.

Work on the new aircraft, the "Bf 109A", had been proceeding in parallel with Bf 108 development, and it was ready to fly by August 1935. It was, like the Bf 108, a low wing, all metal, flush riveted monoplane with leading-edge slats and retractable tailwheel landing gear. It had a single-seat cockpit, with a fully enclosed canopy that hinged open to the right. These innovations were not new in themselves, but the Bf 109A was one of the first aircraft to put them all together.

Since the advanced German engines were not yet available, the first prototype used a British liquid-cooled Rolls-Royce Kestrel VI twelve-cylinder upright-vee engine with 518 kW (695 HP) takeoff power. This engine was used in the other competing fighter prototypes for the same reason.

The first prototype, the "Bf 109V1", where "V1" stood for "Versuchs / Prototype 1", was run through preliminary flight tests in September 1935, and then passed on to the Luftwaffe Test Center at Rechlin. The test pilots were suspicious of the Messerschmitt design. It looked frail compared to the heavier aircraft they were used to; they were uncomfortable with the fully enclosed cockpit, which was cramped in any case; they were unhappy with the aircraft's high wing loading; and didn't like the steep ground angle, which restricted their forward view on takeoff. The head of the RLM procurement office, World War I ace General Ernst Udet, was openly contemptuous, saying: "That will never make a fighter!"

The concerns were completely justified in one respect. The main landing gear of the Bf 109A had a narrow track, hinged in the fuselage to retract into the wings. The narrow gear not only made the aircraft a "roller skate" on the runway but were also weak and prone to collapse. In fact, the prototype suffered a landing gear failure when it was handed over to the Luftwaffe for test. Landing gear problems would be a long-standing difficulty for the Bf 109.

Whatever problems the Bf 109A had on the ground, it was agile and fast in the air, and fighter became one of the front-runners in the competition. Udet overcame his original suspicions and became an enthusiastic advocate of the type.

In the meantime, acting as if he already won the competition, Messerschmitt pressed on with the second and third prototypes. The "Bf 109V2" was completed in October 1935. It was similar to the V1, but used a 455 kW (610 HP) Junkers "Jumo 210A" engine instead of the Kestrel, and had other minor differences, such as a small intake in the cowling to provide cooling for the two machine guns, which were to be mounted there to fire through the propeller arc. The Bf 109V2 was not actually fitted with armament. The third prototype, the "Bf 109V3", was the first armed aircraft in the series, fitted with the required pair of MG 17 7.9-millimeter machine guns, with 500 rounds per gun (RPG). It was otherwise identical to the Bf 109V2. Problems in obtaining the Jumo 210A engine delayed the first flight of the Bf 109V3 until May 1936.

By this time, the Bf 109A was clearly becoming the front-runner in the competition. The Arado and Focke-Wulf entries had fallen to the wayside early on, due to poor performance and mechanical failures, and the Bf 109A was demonstrating itself superior to the Heinkel machine, the "He 112". German intelligence stacked the deck even more clearly in favor of the Bf 109A when they reported that the British were working on a conceptually similar advanced fighter, the Supermarine "Spitfire".

The RLM was sufficiently impressed by the Bf 109A to order ten preproduction aircraft, though they ordered ten He-112s as well. Willy Messerschmitt had won his gamble, and Milch could only fume over giving Messerschmitt as many chances as he had.



* The initial Bf 109 preproduction aircraft, the "Bf 109V4", was first flown in November 1936. It was much like the Bf 109V3, being powered by a Jumo 210A engine, but incorporated a third MG 17 machine gun, situated between the engine cylinders and firing through the propeller hub. The engine-mounted weapon fitted in many Bf 109 variants is often referred to as a "Motorkanone", though it is unclear if this term applied to small-caliber guns as well as automatic cannon. The improved armament was the consequence of reports that new British fighters had four guns instead of two. The question of armament would be another long-running issue for the Bf 109.

Two additional preproduction Bf 109s, designated "Bf 109V5" and "Bf 109V6" were flown in the next two months, featuring an improved "Jumo 210B" engine, as well as a number of other minor enhancements, such as a stronger forward windscreen and replacement of the gun cooling intake by three flush cooling slots.

In 1936, Nazi Germany had decided to assist Generalissimo Franco's Nationalist forces in the Spanish Civil War; participation in a shooting war gave the Luftwaffe an opportunity to evaluate the Bf 109 in combat. The three preproduction aircraft available at the time were sent to Seville in December 1936 and January 1937, to be flown by the German "volunteer" group in Spain, the "Condor Legion". The preproduction aircraft suffered from a number of teething problems in combat service, as would be expected for prototypes. Taking that into consideration, they otherwise gave the Luftwaffe good reason to be excited about the new fighter. The three prototypes were returned to Augsburg, but would be replaced in Spain by improved successors.

In the meantime, the RLM had placed orders for a first batch of 30 production aircraft, with the designation "Bf 109B". The first rolled off the production line in February 1937. They featured a "Jumo 210Da" engine, rated at 507 kW (680 HP) for takeoff, driving a Schwarz two-blade fixed-pitch wooden propeller. The third machine gun that fired through the prop spinner was not fitted, since trials had shown it caused engine overheating problems.

The Bf 109Bs were transferred to the Condor Legion in Spain as soon as their pilots had been trained on the new aircraft, which was given the nickname "Bertha" -- Germans liked to use names as a phonetic alphabet, with "Bertha" being the phonetic for "B", as is "Bravo" in the US. In Spain, the German pilots fought with Soviet Polikarpov I-15s and I-16s, being flown in defense of the Spanish Republican government against Franco's Nationalists. At low altitudes, the maneuverable Polikarpovs could outfight the Bf 109B, and so the Luftwaffe pilots quickly learned to take the fight to high altitudes where they had the advantage.

A Bertha was forced down behind Republican lines later in the civil war when it ran out of fuel, and the French discreetly asked to inspect the aircraft. The Republicans agreed to the request. A French team went to Spain and wrote up a detailed report that praised the aircraft -- but the report was marked SECRET to avoid a diplomatic squabble, and few ever read it.

Messerschmitt Bf 109B

* Following the first batch of 30 Bf 109Bs, in July 1937 the propeller was changed from the fixed two-blade wooden propeller to a variable-pitch two-blade metal propeller. The new propeller was an American Hamilton Standard design, built under license by the German firm VDM.

Some sources claim the preproduction aircraft were "Bf 109B-0s"; the 30 machines with the Schwarz propellers were "Bf 109B-1s"; and the remainder of Bertha production were "Bf 109B-2s". Other sources claim no such distinction was made at the time, with the subvariant designations later applied retroactively. Whatever the case, BFW couldn't make the Bf 109 fast enough to make the Luftwaffe happy. New manufacturing facilities were in construction at Augsburg, but to fill the need a license manufacturing agreement was signed with Fieseler, which began to roll out the Bf 109 from its Kassel facility in December 1937.

* By this time the improved "Jumo 210G" and "Jumo 210Ga" engines were becoming available; they featured fuel injection, a two-stage supercharger, and were rated at 522 kW (700 HP) for takeoff. A Jumo 210G had been evaluated in the "Bf 109V7", which first flew in March 1937, and late Bf 109B-2 production featured this engine fit.

The "Bf 109V8" prototype was fitted with the Jumo 210Ga, as well as an extra pair of MG 17 7.9-millimeter guns, one in each wing with 420 RPG, for a total of four guns. A similar "Bf 109V9" was built as well, but replaced the wing machine guns with MG FF 20-millimeter cannon with 60 RPG. The MG FF cannon was suffering from teething problems at the time, and so the production "Bf 109C-1" was much like the Bf 109V8, with four MG 17 machine guns and the Jumo 210Ga, but also added an "FuG-7" radio that permitted, for the first time in the Bf 109 series, communications with ground troops. Incidentally, the Jumo 210Ga engine was also fitted to very late production Bf 109Bs.

The first "Claras", as the C variant was called by Luftwaffe pilots, were rolled off the production line at Augsburg in March 1938, and were rushed off to fight in Spain.

   _____________________   _________________   _______________________
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                9.87 meters         32 feet 4 inches
   wing area               16.17 sq_meters     174.05 sq_feet
   length                  8.55 meters         28 feet 1 inches
   height                  2.45 meters         8 feet

   empty weight            1,597 kilograms     3,522 pounds
   loaded weight           2,296 kilograms     5,062 pounds

   max speed at altitude   470 KPH             290 MPH / 255 KT
   service ceiling         8,400 meters        27,600 feet
   range                   650 kilometers      405 MI / 350 NMI
   _____________________   _________________   _______________________

The Bf 109C-1 was followed by the experimental "Bf 109C-2", which had a fifth MG 17 7.9-millimeter Motorkanone, with improved insulation and cooling mechanisms to hopefully eliminate the overheating problems caused by this fit in earlier Bf 109 subtypes. However, the C-2 was not produced.

The "Bf 109C-3" was also an experimental type, like the Bf 109C-1 but featuring wing-mounted MG FF 20 millimeter cannon instead of the wing-mounted MG 17 machine guns, and the "Bf 109C-4" was similarly like the Bf 109C-1 but had an MG FF Motorkanone.

* While the improved Junkers Jumo engines were welcome, they still were unable to push the Bf 109 past 480 KPH (300 MPH). What Messerschmitt really wanted for the Bf 109 was the Daimler-Benz 600 (DB 600) engine.

The "Bf 109V10" prototype was originally built in a configuration much like that of the Bf 109V8, with a Jumo 210Ga engine, but it was then refitted with a "DB 600a" engine, rated at 671 kW (900 HP) for takeoff. Ernst Udet flew the re-engined Bf 109V10 at a flying meet in July 1937, in an attempt to make a new speed record, but ended up crash-landing the aircraft.

The Bf 109V10 was replaced for powerplant testing by the "Bf 109V11", fitted with the modestly improved "DB 600A" engine. The following "Bf 109V12" and "Bf 109V13" were similar, but the Bf 109V13 was soon upgraded to the "DB 601", with 876 kW (1,175 HP) for takeoff and greater reliability. The improved Bf 109V13 set a world speed record of 610.5 KPH (379.38 MPH) in November 1937.

The DB 601 was expected to be the proper powerplant for the Bf 109. Not only was it very powerful, but it was fuel-injected and could operate effectively in negative-gee maneuvers that would cause a carbureted engine to stall. However, there were problems: working out the bugs in the new engine was proving troublesome, the automatic supercharging system proving a great nuisance; Daimler-Benz couldn't build the engine in the needed quantities; and priority for engine deliveries had been given to the Heinkel He 111 bomber.

* These difficulties led to the production of an interim aircraft, the "Bf 109D", using Jumo 210D and 210G powerplants that were available. Roughly 200 Bf 109Ds, referred to as "Dora" by Luftwaffe pilots, were built, with subvariants designated "Bf 109D-1" through "Bf 109D-3" and differing in armament fit.

The Bf 109D-1 tried the three-gun armament again, with an MG FF 20 millimeter Motorkanone, but the weapon tended to jam and still caused overheating problems, and so the Bf 109D-2 went back to the four MG 17 7.9 millimeter guns of the Bf 109C-1. The Motorkanone was often pulled out of the Bf 109D-1 in the field. The Bf 109D-3 traded up the wing-mounted MG 17s for MG FF 20-millimeter cannon, a fit like that of the Bf 109C-4; the Bf 109D-3 actually saw operational service, though it was only built in small numbers.

The Dora was sent to Spain to prove itself in combat, and young Condor Legion pilots like Adolf Galland and Werner Moelders clearly demonstrated its value. Moelders was not merely a good fighter pilot but also an excellent air tactician, and devised new fighter tactics, such as the "finger four" formation that the Germans called the "Schwarm", and a more flexible approach to air-to-air combat than was practiced by other air arms at the time. Moelders would leave Spain with 14 kills, making him the highest scorer of the campaign.

* While the evolution of the Bf 109 was in progress, there was also a significant change at BFW. The fighter had given Willy Messerschmitt international recognition, and so the RLM suggested that BFW could improve its international recognition by changing its name to "Messerschmitt AG". Aircraft already in production by BFW would retain the "Bf" designation for the rest of their careers, but all new aircraft from the company would have the "Me" designation. The name "Messerschmitt" would become even more famous as his designs proved their worth against Germany's adversaries, and Nazi propaganda trumpeted their victories.


[1.4] BF 109E

* The first really satisfactory version of the Bf 109 was the "Bf 109E". The Bf 109V13, mentioned above, was the first "Bf 109E-0", and was followed by seven more Bf 109E-0s ("Bf 109V14" through "Bf 109V20"), with minor variations in equipment fit.

The "Bf 109V21" and "Bf 109V22" are stated in some sources as being Bf 109E-0s, but other sources apply these two prototype numbers to the initial two "F" series prototypes, discussed later. Duplication of the designations seems unlikely, and given the fact that earlier prototype versions underwent changes in definition, it is plausible that they started out as "E" prototypes and ended up being "F" prototypes instead.

The initial "Bf 109E-1" subvariant was first delivered to the Luftwaffe in early 1939 and featured the DB 601A-1 engine, as well as a three-bladed variable-pitch propeller. Although earlier Bf 109 variants had featured a "chin" engine radiator, the Bf 109E featured twin radiators, mounted one under each wing. The Bf 109E was not quite as agile as the Bf 109D, but it was substantially faster, and in fact was one of the most potent fighters in the world at the time.

The Bf 109E-1 featured armament of four MG 17 7.9-millimeter machine guns, with two in the cowling and two in the wings. The cowling guns had 1,000 RPG, while the wing guns had 420 RPG. Twenty Bf 109E-1s were turned out in time to be sent to Condor Legion in Spain before the civil war ended in March 1939. By this time, Republican resistance was crumbling and the new fighters met little opposition. In the end, a total of some 200 Luftwaffe pilots served with the Condor Legion, obtaining combat experience that would make Germany's fighter pilots an elite in the campaigns to come. They left the twenty Bf 109E-1s behind for the Spaniards.

Manufacture of the Bf 109E, referred to as the "Emil" by Luftwaffe pilots, continued to ramp up, although Messerschmitt production was shifted from Augsburg to Regensburg to make way for the Bf 110 twin-engine fighter. Other aircraft manufacturers were brought in to help feed the Luftwaffe's appetite for the Bf 109.

* By the time Germany invaded Poland in September 1939, the Luftwaffe was flying about 850 Bf 109Es and 235 Bf 109Ds. The invasion was a complete success, overwhelming Polish resistance in a rapid "Blitzkrieg (Lightning War)". A little over 200 Bf 109s participated in the invasion, with 67 being lost, mostly to ground fire. After the invasion, things went quiet again as the British and French went passive, resulting in the "Sitzkrieg (Sitting War)".

However, from the start of the war the British Royal Air Force (RAF) performed small-scale raids on German territory. These actions climaxed in the biggest air battle of 1939, on 18 December 1939, when the RAF attacked Wilhelmshaven in daylight with 24 unescorted Vickers Wellington bombers. The Luftwaffe had a party with them, shooting down 12 of the Wellingtons and damaging three others badly. The Luftwaffe lost two Bf 109s. The British decided to reconsider their tactics, switching to night bombing.

There were intermittent air skirmishes over the French border during the Sitzkrieg. The French and British found the Bf 109 a nasty opponent; they were desperate to figure out its strengths and weaknesses. Luckily for them, in November a confused Luftwaffe pilot set an Emil down on the wrong side of the border, with the aircraft eventually ending up in England the following spring, for flight tests and mock dogfights with British fighters. An Emil had similarly fallen into French hands back in September, but it had been lost in a mid-air collision before serious evaluation could be conducted with it.

The British evaluation showed the Emil completely superior to the Hawker Hurricane in almost all respects, and generally superior to a Spitfire Mark I equipped with a two-bladed propeller. With a three-bladed Rotol propeller, the Spitfire Mark I had the upper hand at high altitude. This particular Messerschmitt is now in the RAF museum at Hendon in the UK.

* The Doras were gradually phased out as new Emil subvariants were introduced. The "Bf 109E-2" was supposed to have been fitted with the MG FF 20-millimeter Motorkanone, but this subvariant was not actually built.

The "Bf 109E-3" featured a DB 601Aa engine with 895 kW (1,200 HP) for takeoff. The Bf 109E-3 also had a stronger canopy design; armor plate in the seat, and above the pilot's head; and replaced the MG 17 wing guns with MG FF 20-millimeter cannons with 60 RPG each. The bigger weapons dictated fit of a blister in the lower wing. The pilot had a selector switch to permit firing one or both cannons.

The definitive Emil variant, the "Bf 109E-4", was very similar to the Bf 109E-3, but the MG FF wing cannon were updated to MG FF/M cannon. The MG FF/M was externally identical to the MG FF, but had a "softened" recoil mechanism to allow it to fire devastating high-explosive "mine" shells. The softened recoil mechanism also resulted in a higher rate of fire.

   _____________________   _________________   _______________________
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                9.87 meters         32 feet 4 inches
   wing area               16.17 sq_meters     174.05 sq_feet
   length                  8.64 meters         28 feet 4 inches
   height                  2.50 meters         8 feet 2 inches

   empty weight            1,900 kilograms     4,190 pounds
   loaded weight           2,665 kilograms     5,875 pounds

   max speed at altitude   560 KPH             350 MPH / 300 KT
   service ceiling         10,500 meters       34,500 feet
   range                   660 kilometers      410 MI / 355 NMI
   _____________________   _________________   _______________________

When the Blitzkrieg against the Low Countries and France began in the spring of 1940, the Emil led the way, quickly gaining mastery over all opponents. The offensive was over in a matter of weeks.

The campaign in France had suggested the need for fighter-bomber ("Jagdbomber / Jabo") aircraft, and a number of Bf 109s and Bf 110s were experimentally fitted with centerline bomb racks. They performed attacks on Channel shipping, and the combat tests proved so successful that the Luftwaffe decided to create Jabo Bf 109 squadrons.

Messerschmitt Bf 109E

The first Bf 109 Jabo subvariant, the "Bf 109E-1/B", was a field conversion of existing Bf 109E-1s, featuring a centerline rack for a single 250-kilogram (550-pound) bomb, though more normally it carried a single 50-kilogram (110-pound) bomb to achieve greater range. Bf 109-E4s were also fitted with the rack in production, this modification being given the designation "Bf 109-E4/B". These Jabo subvariants were not fitted with a bombsight as such, but the standard Revi gunsight could be used in dive attacks with some accuracy, and a line was painted on the windscreen to help the pilot with his attack.

The Bf 109's centerline rack is a confusing subject. Such racks would be fitted to subvariants or modifications of the aircraft through the rest of its evolution, allowing the carriage of a 250-kilogram (550-pound) bomb, four 50-kilogram (110-pound) bombs, or a 300-liter (80 US gallon) drop tank. However, it is very unclear whether the same rack could be alternatively fitted with all three of these stores configurations, or whether different racks handled different subsets of them.

* Despite the success of the Bf 109E in the French campaign, some worries cropped up. For one, the Bf 109's range had proven inadequate. For another, the Bf 109E had come up against the British Supermarine Spitfire fighter during the mass evacuation of Allied troops at Dunkirk, and the British fighter had proven a formidable opponent.

These worries would become critical as the Luftwaffe shifted its attention across the English Channel. At first, things went well for the Luftwaffe. After the beginning of the Battle of Britain on 13 August 1940, the Bf 109s were allowed to range freely and engage British fighters at will, using the fluid tactics devised by Moelders in Spain. The British had been trained in traditional inflexible formation tactics that put them at a disadvantage, but the RAF quickly adopted the Luftwaffe's tactics.

While the Bf 109s ranged freely, the job of protecting the bombers fell to the twin-engine Bf 110s. The strategy didn't work. The Bf 110s were slaughtered, and so by early September the Bf 109s were ordered to operate as bomber escorts. Forced into a defensive posture, the Bf 109 was at a disadvantage relative to Hurricanes and Spitfires. The limited range of the Bf 109 was also proving a liability, since it could not stay over the battle area for very long before having to return home. After the bombings campaign was switched from British airfields to British cities, the RAF began to gain the upper hand.

The last action of the Battle of Britain was on 31 October 1940. The British had lost 631 Hurricanes, 403 Spitfires, and 115 Blenheim fighters, for a total of 1,149 aircraft. The Luftwaffe lost 610 Bf 109s, along with 235 Bf 110s and 937 bombers, for a total of 1,782 aircraft. Worse, many of the British pilots who had to bail out returned to battle the next day, while Luftwaffe pilots who bailed out went to prisoner of war camps. From a tactical point of view, the battle was not all that lopsided and could be regarded as a standoff. However, it was a moral victory for the British, who had been the first to stand up to Hitler and make him back off; and a moral defeat for the Luftwaffe, which had been used to victories.

* The Bf 109 was still a dangerous adversary, and its cannon armament was devastatingly effective against RAF fighters armed with rifle-caliber machine guns, another lesson the RAF would absorb. Werner Moelders was the first of Hitler's Luftwaffe pilots to exceed 50 kills, with Adolf Galland close behind him.

The Luftwaffe was still enthusiastic for the Bf 109, and new versions of the Emil were rolled out. The uprated DB 601N powerplant, with 895 kW (1,200 HP) for takeoff, was fitted to the to produce the "Bf 109E-4/N" modification.

"Fighter reconnaissance" subvariants were produced, such as the "Bf 109E-5" and "Bf 109E-6", which deleted the wing guns and featured a camera in the rear fuselage. The Bf 109E-5 was fitted with the DB 601Aa engine, while the Bf 109E-6 was fitted with the uprated DB 601N engine.

A long-range fighter / Jabo variant, the "Bf 109E-7", was produced with a rack for a 300 liter (80 US gallon) centerline drop tank or 250 kilogram (550 pound) bomb. A "Bf 109E-7/U2" modification was produced for ground attack with armor protection for critical engine systems, and a "Bf 109E-7/Z" modification was built for high-altitude operation using GM 1 nitrous oxide engine boost. The nitrous oxide provided supplemental oxidizer for the engine, with the nitrous oxide bottle placed under the pilot's seat. However, the nitrous oxide kit was heavy and its placement disturbed the balance of the aircraft, leading to unpleasant stall-spin characteristics.

Meanwhile, in Africa, after being introduced to the theater in April 1941, the Bf 109E was enjoying the success to which it had been accustomed, racking up large numbers of kills against RAF Hurricanes and Kittyhawks. The Emil was modified for African operations by being fitted with engine sand filters and a desert survival kit. The survival kit contained food and water, a lightweight carbine, signal equipment, and other gear. The result were the "tropicalized" subvariant modifications, designated with the suffix "Trop". "Bf 109E-4/Trop", "Bf 109E-5/Trop", and "Bf 109E-7/Trop" subvariants were introduced.

The last two major subvariants of the Emil were the "Bf 109E-8" and the "Bf 109E-9". The Bf 109E-8 was similar to the Bf 109E-1 in having an armament of four MG 17 7.9-millimeter guns, but had a DB 601E engine with 1,007 kW (1,350 HP) for takeoff, and a centerline rack for a bomb or drop tank.

The Bf 109E-9 was a long-range reconnaissance version, with a camera in the rear fuselage, two 7.9-millimeter machine guns in the cowling, and a centerline rack. Some sources claim it had the DB 601E engine and no wing guns, while others say it had the earlier DB 601N engine and an MG FF 20-millimeter cannon under each wing. The first configuration seems slightly more plausible, since the DB 601N would have been a throwback to earlier subvariants, and wing guns were not fitted to other reconnaissance subvariants of the Bf 109. The mission did not call for heavy armament and removal of the wing guns compensated for the weight of the camera.

In any case, the Bf 109E-8 and Bf 109E-9 were only built in small quantities. They were the last of the roughly 4,000 Emils built. Luftwaffe interest had clearly moved on to something more advanced.