Messerschmitt Bf 109

Willy Messerschmitt began designing this revolutionary aircraft as early as 1934 at the Bavarian Aircraft Works (hence the Bf) in Haunstetten. The all-metal aircraft first flew in May 1935. The construction stood out in many respects from the hunting single-seaters of the time; there was a retractable landing gear and a closed pilot’s pulpit. From 1937, the aircraft was the standard fighter of the air force. The aircraft was built until the end of the Second World War, and around 33,000 units of all series left the various factory halls.

Messerschmitt had extensive experience in the construction of all-metal aircraft at an early stage, a design that was not taken for granted at the time. Messerschmitt was also able to inspire Richard Bauer, an Arado designer, for his ideas. In 1934 Messerschmitt presented the BFW Bf108, a design that was sensational at the time. This fast passenger aircraft with retractable landing gear should be the basis for a new fighter aircraft. Not an easy task for Richard Bauer and his team.

The plan was simple. A powerful engine as possible should be installed in a cell that is as light as possible, virtually an aircraft around the engine. The typical Messerschmitt half-shell construction was the key to success. Self-supporting half-shells with longitudinal profiles proved to be very stable with the lowest possible weight. The structure also had to be very light. The single-bar all-metal construction was kept quite small, so rather buoyant, but fast. In order to obtain balanced properties, it was a long time that the aerodynamic trick box had to be reached. Revolutionary at the time, the structure was equipped with automatic forewings and split-landing flaps.

At the time of development, closed pilot pulpits were not the standard. The pilots wanted to be able to leave the driver’s room as soon as possible in an emergency, because a closed hood was rather unhelpful. Here, too, the design team found a remedy with a right-hand hinged, hinged cabin hood. The pilot only had to unlock and hit the hood in an emergency, the rest was taken over by the wind.

Messerschmitt and his team were not only thinking about flying this fighter plane, he was thinking further logistically. Modular design is the magic word. Messerschmitt disassembled the aircraft into individual modules that could be assembled independently of each other, a step into decentralized production. The modular design also facilitated maintenance and repair work for the flying units on site. Quick replacement of damaged parts was the goal.

The catalogue also included the fact that the fuselage can be moved without aids. For this purpose, it was necessary to make the cell rollable without wings, wants to hot the chassis was attached to the fuselage. Thus, the equipped aircraft cell could be moved quite easily in the shipyard without having to .B cranes. This idea and also the desired loading possibility on normal railway wagons of the Deutsche Reichsbahn, however, led to the relatively small gauge of the main landing gear, ultimately one of the Achilles heels of this aircraft design.

The measure of the gauge was the result of the so-called “light space profile” of the Deutsche Reichsbahn. This profile prescribes maximum widths for web loading. As a further constructive aspect, it was the three-division of the wing main spar. The advantage is clearly the fast loading possibility, the feasibility of field repairs without additional equipment and the possibility of returning damaged aircraft to the shipyard without needing special wagons.

However, the price of the logistical feat was very high. The aircraft tended to dangerous breakout during take-off due to its high engine power due to its high engine power due to poor seats, side and shear winds. Many pilots paid for this unspecies with their lives. Some sources speak of more losses due to landing and take-off accidents than from the downing of an enemy aircraft. Especially towards the end of the war, the poor level of training of the pilots led to high losses in this type of accident. Nevertheless, in the hands of an expert, the heavily motorized and light Messerschmitt Bf109 was a dangerous and balanced weapon.

The most famous series are probably the “Emil” with the DB601, the “Friedrich” with DB601E and the “Gustav” with the DB605. The “Emil” is usually associated in one breath with the “Air Battle for England”. The “Friedrich” is considered the most balanced and beautiful Bf109 and of course one connects the “Friedrich” with the famous JG27 over Africa, with Hans-Joachim Marseille as pilot. The “Gustav” is the most famous series and was a feared opponent in all theatres of war. Various sub-variants, countless set-up kits and also basis for various license buildings. The “Gustav” was also the most built variant, with around 20,000 copies leaving the various production sites.

The Messerschmitt Bf109 was also exported, so the fighter aircraft was also used by the Swiss air troops. After the war, the licensed buildings also followed in Israel and Czechoslovakia.

A word about the licensed buildings. After the war, the Bf109 was continued to be built. For example, the G-10 series at Avia in Czechoslovakia, type designation Avia S-199. As a motorization, the licensees chose the Junkers aggregate JUMO 211F , because the Daimler-Benz units were no longer available. Among other things, the Israeli Air Force used this type of aircraft. In the Palestine War, former adversaries met again. The Egyptian Air Force countered the Avia S-199 Spitfires.

In Spain, production continued at Hispano Aviacion. The “Buchon”, which is called HA-1109 and HA-1112, was equipped with a RollsRoyce/Packard Merlin. Willy Messerschmitt had a not inconsiderable influence on the production and interpretation of the “Buchon”, he worked as a designer at Hispano Aviacion after the war.

History of Hispano Aviacion HA-1112 “Buchon”

Prototypes
Design work on Messerschmitt Project Number P.1034 began in March 1934, just three weeks after the development contract was awarded. The basic mock-up was completed by May, and a more detailed design mock-up was ready by January 1935. The RLM designated the design as type “Bf 109,” the next available from a batch of numbers assigned to BFW.

The first prototype (Versuchsflugzeug 1 or V1), with civilian registration D-IABI, was completed by May 1935, but the new German engines were not yet ready. In order to get the “RIII” designs into the air, the RLM acquired four Rolls-Royce Kestrel VI engines by trading Rolls-Royce a Heinkel He 70 Blitz for use as an engine test-bed.

Messerschmitt received two of these engines and adapted the engine mounts of V1 to take the V-12 engine upright. V1 made its maiden flight at the end of May 1935 at Haunstetten, piloted by Hans-Dietrich “Bubi” Knoetzsch. After four months of flight testing the aircraft was delivered in September to the Luftwaffe test centre at Rechlin to take part in the design competition.

In the late summer of 1935, the first Jumo engines became available so V2 was completed in October using the 449 kW (600 hp) Jumo 210A engine. V3 followed, the first to be mounted with guns, but it did not fly until May 1936 due to delay in procuring another Jumo 210 engine.
Design & developement
The fighter needed to have a top speed of 400 km/h (250 mph) at 6,000 m (19,690 ft), to be maintained for 20 minutes, while having a total flight duration of 90 minutes. The critical altitude of 6,000 metres was to be reached in no more than 17 minutes, and the fighter was to have an operational ceiling of 10,000 metres. Power was to be provided by the new Junkers Jumo 210 engine of about 522 kW (700 hp).

It was to be armed with either a single 20 mm MG C/30 engine–mounted cannon firing through the propeller hub as a Motorkanone or, alternatively, either two engine cowl-mounted 7.92 mm (.312 in) MG 17 machine guns, or one lightweight, engine-mounted 20 mm MG FF cannon with two 7.92 mm MG 17s. The MG C/30 was an airborne adaption of the 2 cm FlaK 30 anti-aircraft gun, which fired very powerful “Long Solothurn” ammunition, but was very heavy and had a low rate of fire. It was also specified that the wing loading should be kept below 100 kg/m2. The performance was to be evaluated based on the fighter’s level speed, rate of climb, and manoeuvrability, in that order.

Messerschmitt Bf 109 G-2/trop “Black 6”, WkNr 10639
It has been suggested that Bayerische Flugzeugwerke (BFW) was originally not invited to participate in the competition due to personal animosity between Willy Messerschmitt and RLM director Erhard Milch; however, recent research by Willy Radinger and Walter Shick indicates that this may not have been the case, as all three competing companies—Arado, Heinkel and the BFW—received the development contract for the L.A. 1432/33 requirements at the same time in February 1934.

A fourth company, Focke-Wulf, received a copy of the development contract only in September 1939. The powerplant was to be the new Junkers Jumo 210, but the proviso was made that it would be interchangeable with the more powerful, but less developed Daimler-Benz DB 600 powerplant. Each was asked to deliver three prototypes to be delivered for head-to-head testing in late 1934.
Design & feature
As with the earlier Bf 108, the new design was based on Messerschmitt’s “lightweight construction”, which was essentially aimed at reducing the total number of parts in the aircraft as much as possible. Examples of this could be found in the use of two large, complicated brackets which were fitted to the main engine firewall; these brackets incorporated the lower engine mounts and landing gear pivot points.

A large forging attached to the firewall carried the main-spar pick up points, and carried most of the wing loads. Contemporary design practice was usually to have these main load-bearing structures mounted on different parts of the airframe, with the loads being distributed through the main structure via a series of strong-points. By centralising the loads on the main bulkhead, the main structure of the Bf 109 was able to be made relatively light and uncomplicated.

An advantage of this design was that because the outboard-retracting main landing gear, retracting through roughly an 85º angle, was attached to the fuselage, it was possible to completely remove the wings of the aircraft for servicing without the need for additional equipment to support the fuselage. It also meant that the wing structure was able to be simplified through not having to carry the weight of the aircraft and not having to bear the loads imposed during takeoff or landing.

However, this had one major drawback—this landing gear arrangement had a narrow wheel track making the aircraft unstable while on the ground. To increase stability the legs had to be splayed out, creating another problem in that the loads imposed during takeoff and landings were transferred at an angle up through the legs.

Messerschmitt Bf 109 G-2/trop “Black 6”, WkNr 10639
The small rudder of the Bf 109 was relatively ineffective at controlling the strong swing created by the powerful slipstream of the propeller, and this sideways drift created disproportionate loads on the wheel opposite to the swing. If the forces imposed were large enough, the pivot points often broke and the landing gear leg would be forced sideways into its bay.

Because of the large ground angle caused by the long legs, visibility for the pilot, especially straight ahead, was very poor, a problem exacerbated by the sideways-opening canopy. This meant that the pilots often had to “snake” the aircraft during taxiing manoeuvres, which again imposed stresses on the splayed undercarriage legs. Ground accidents were, however, more of a problem with rookie pilots, especially during the later stages of the war.Most Finnish pilots reported that the swing was easy to control, but some of the less-experienced pilots lost fighters on startup.At least 10% of all Bf 109s were lost in takeoff and landing accidents, 1,500 of which occurred between 1939 and 1941.

The provision of a fixed “tall” tailwheel on some of the late G-10s and 14s and the K-series helped alleviate the problem to a large extent. Automatic leading edge slats on a Bf 109E. By using high-lift devices, the handling qualities of the Bf 109 were considerably enhanced.

From the inception of the design priority was given to total and easy access to the powerplant, fuselage weapons and other systems while the aircraft was operational from forward airfields. To this end, the entire engine cowling was made up of large, easily removable panels which were secured by large toggle-latches. A large panel under the wing centre-section could be removed to gain access to the L-shaped main fuel tank, which was sited partly under the cockpit floor and partly behind the rear cockpit bulkhead. Other, smaller panels gave easy access to the cooling systems and electrical equipment.

The engine was held in two large, forged, magnesium alloy Y-shaped legs which were cantilevered from the main firewall/bulkhead. Each of the legs was secured by two quick-release screw fittings on the main firewall. All of the main pipe connections were colour-coded and grouped in one place, where possible, and the electrical equipment plugged into junction boxes mounted on the firewall. The entire powerplant could be removed or replaced as a unit in a matter of minutes.

An aspect of this construction technique was the use of a single, I-section main spar in the wing, mounted close to the leading edge, thus forming a stiff D-shaped torsion box. Most aircraft of the era used two spars, near the front and rear edges of the wings, but the D-box was much stiffer torsionally, and eliminated the need for the rear spar. The wing profile was somewhere between NACA 2314 and 2315, with a thickness to chord ratio of 14.5%.

Another major difference was the higher wing loading than the competing designs. While the R-IV contract called for a wing loading of less than 100 kg/m2, Messerschmitt felt this was unreasonable; with the engines available to them, the fighter would end up slower than the bombers it was tasked with catching.[citation needed]

Since the fighter was being designed primarily for high-speed flight, a smaller wing area would be optimal for achieving high level speeds, but the downside of such a trade-off was that low-speed flight would suffer, as the smaller wing would require more airflow to generate enough lift to stay flying. To compensate for this, the Bf 109 included advanced high-lift devices on the wings, including automatically opening leading edge slats, and fairly large camber-changing flaps on the trailing edge. The slats increased the overall lift of the wing considerably when deployed, greatly improving the horizontal maneuverability of the aircraft, as several Luftwaffe veterans, such as Erwin Leykauft.

Messerschmitt also included ailerons (and later radiator flaps) that “drooped” when the flaps were lowered thereby increasing the effective flap area. When deployed, these devices effectively increased the wings’ coefficient of lift. Fighters with liquid cooled engines were vulnerable to hits to their coolant system. For this reason, on later Bf 109 F, G and K models the two coolant radiators were equipped with a cut-off system: if one radiator leaked, it was possible to fly on the second, or close both radiators down and fly at least five minutes more.
Flight and maintenance manual

Sound

Take off left to right

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