Messerschmidt ME-109...........................................................Specifications
The Messerschmitt Bf 109 was a German World War II fighter aircraft designed by Willy Messerschmitt in the early 1930s. It was one of the first true modern fighters of the era, including such features as an all-metal monocoque construction, a closed canopy, and retractable landing gear. The Bf 109 was produced in greater quantities than any other fighter aircraft in history, with a wartime production (September 1939 to May 1945) of 30,573 units. Fighter production totalled 47% of all German aircraft production, and the Bf 109 accounted for 57% of all German fighter types produced.] 2,193 Bf 109 A-E were built prewar, from 1936 to August 1939. An additional 1,000 or so were manufactured postwar under licence as Czechoslovakian built Avia S-99 & S-199s and Spanish Hispano Aviación HA-1109 and HA-1112 Buchons.
Ironically the 109, one of Germany,s key fighter aircraft of World War Two, started and ended life with a Rolls Royce engine. The Prototype V1 had a Kestrel VI engine due to the lack of a German engine capable of powering it, and the last version (all be it Spanish built) manufactured after the war, the HA 1112 was powered by a Merlin Engine.
Although the 109 was being partially replaced by the Focke-Wulf Fw 190 from 1941 onwards, this neat fighter scored more aircraft kills in World War II than any other aircraft. At various times it served as an air superiority fighter, a bomber escort, an interceptor, a ground-attack aircraft, and a reconnaissance aircraft. Although the Bf 109 had weaknesses, including a short range, and especially a sometimes difficult to handle narrow, outward-retracting undercarriage, it stayed competitive with Allied fighter aircraft until the end of the war.
The first prototype (Versuchsflugzeug 1 or V1), with the civilian registration D-IABI, was completed by May 1935, but the German engines were not yet ready. In order to get the designs into the air, the RLM acquired four Rolls-Royce Kestrel VI engines by trading Rolls-Royce a Heinkel He 70 Blitz as an engine test-bed. Messerschmitt received two of these engines and started adapting the engine mounts of V1 to take the inverted Vee-12 engine. This work was completed in August, and V1 completed flight tests in September 1935. The aircraft was then sent to the Luftwaffe Test Center at Rechlin to take part in the design contest.
By the late summer, the Jumo engines were starting to become available, and V2 was completed with the 602 hp (449 kW) Jumo 210A in October 1935. V3 followed, being the first to actually mount guns, but another Jumo 210 was not available and it ended up delaying the flight of V3 until May 1936. Like V1, V2 and V3 were sent to Rechlin after acceptance tests at the factory.
The flight data of these three aircraft were very nearly identical. The maximum airspeed was about 470 km/h at 4,000 m altitude, and the service ceiling was about 8,300 m.
The new design of the 109 was based on Messerschmitt's "lightweight construction", which essentially aimed at reducing the total number of parts in the aircraft as much as possible. One of the more notable examples of this were the two large, complicated brackets which were fitted to the main engine firewall; these brackets incorporated the lower engine mounts and landing gear pivot points. Another large forging which was attached to the firewall carried the main-spar pick up points, which carried most of the wing loads. Contemporary design practice was usually to have these main load-bearing structures mounted on different parts on 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 109 was able to be made relatively light and uncomplicated.
Another notable advantage of this design was that, since the landing gear was attached to the fuselage itself, it was possible to completely remove the wings of the aircraft for major servicing, if necessary, leaving the fuselage intact sitting on the landing gear. 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 take-off or landing. However, this had one major drawback, this landing gear arrangement ensured a narrow track and hence made the aircraft unstable in terms of balance while on the ground. In an attempt to increase the wheel track the legs were splayed out; this created another problem in that loads imposed during take-off and landings were transferred at an angle up the legs. The small rudder of the 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 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. The Spitfire had a similar, narrow landing gear arrangement, but because there were no sideways loads imposed on the undercarriage legs the undercarriage didn't have the same tendency to collapse.
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.
Although there have been suggested that from five to 33% of all 109s were damaged or destroyed in this way, the Luftwaffe's loss records show that approximately 1% of the Bf 109s had suffered landing incidents or accidents at the beginning of its career, a figure comparable to the other monoplane fighters introduced at the time. Ground accidents were, however, more of a problem with rookie pilots, especially during the later stages of the war. Even experienced pilots, especially those who were tired, were caught out. Most Finnish pilots report that the swing was easy to control, but some of the less experienced pilots lost fighters on startup. As more powerful engines and larger propeller blades were used the swing became more pronounced, although 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.
Right 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.
Reflecting Messerschmitt's belief in low-weight, low-drag, simple monoplanes, the armament was placed in the fuselage; two machine guns were mounted in the cowl, while a third could be fired through the airscrew hub, with the engine buffering the recoil. Fitting with Dr Messerschmitt's ethos, this kept his gun-free wings very thin and lightweight. When it was discovered the RAF was producing eight-gun monoplanes, it became clear the Bf 109 would need to carry more weaponry; a new wing was designed to carry machine guns, and later, 20 mm MG FF cannon configurations.
In 1938 the "Emil" entered production. To improve on the performance allowed by the rather small 600 to 700 hp Jumo, the larger Daimler Benz DB 601A engine was used, yielding an extra 300 hp at the cost of an additional 400 lb.
By 1937 it had become clear that the 109 was too lightly armed, especially when compared with the eight machine guns which armed the new RAF fighters, the Hawker Hurricane and Supermarine Spitfire. The problem was that when it came to fitting additional armament the only place in which it could be located was in the wings. However, the positions of the undercarriage bays, main spar and wing slots meant that room was limited to two bays between the undercarriage and slots. There was room for only one weapon per wing, either an MG 17, or an MG FF or MG FF/M. The first version of the 109 to have wing guns was the C-1, which had one MG 17 per wing fitted in the inner bays. To avoid redesigning the wing to accommodate large ammunition boxes and access hatches an unusual ammunition feed was devised whereby a continuous belt, holding 500 rounds of ammunition, was fed along chutes out to the wingtips. The belt was fed around a roller and back along the wing, forward and beneath the gun breech, to the wingroot where it was fed around another roller and back to the weapon. The gun barrels were buried in long, large diameter tubes between the spar and the leading edge. These tubes channelled cooling air around the barrels and breeches and was ejected via a slot at the rear of the wing diaphragm and top of the flap. Room was still so restricted that parts of the MG 17's breech mechanism poked into an accommodating hole in the flap structure.
The much longer and heavier MG FF had to be mounted in the outer bay. A large hole was to be cut through the spar webbing to allow the cannon to be fitted with ammunition feed forward of the spar and the rear breech block projecting through the spar. The 60 round ammunition drum was placed in the machine-gun compartment; a small hatch incorporating a blister was needed in the wing lower surface to allow access to change the drum. The entire weapon could be removed for servicing by removing a leading edge panel. From the 109F series very few 109s had weapons mounted within the wings, with any additional guns being mounted in drag-inducing pods under the wings.
The BF/ME 109 was built in various versions.
The Bf 109A ("Anton") was the first version of the Bf 109. The armament, planned to be only two cowl-mounted 7.92 mm MG 17 machine guns. However, possibly due to the introduction of the Hurricane and Spitfire, each with eight machine guns, led to experiments with a third machine gun firing through the propeller shaft. V4 and some A-0 were powered by a 640 PS Jumo 210B engine driving a two-bladed fixed-pitch propeller. As soon as the 670 PS Jumo 210D became available production was changed to this engine. The A-0 were not of a uniform type but saw several changes in their appearance. Visible changes include engine, cockpit and machine gun ventilation holes/slats as well as changing the location of the oil cooler several times to prevent overheating. Many of those Bf 109A-0 served with the Condor Legion and were often misidentified as B-series aircraft; they probably served in Spain with the tactical markings 6-1 to 6-16 . One A-0, marked as 6-15, ran out of fuel and was forced to land behind enemy lines. It was captured by Republican troops on 11 November 1937 and later transferred to the Soviet Union for a closer inspection . 6-15 incorporated several improvements from the Bf 109B production program and was able to use the variable-pitch propeller.
According to RLM documentation 22 aircraft were ordered and delivered with V4 as the A-series prototype.
The first Bf 109 in serial production, the Bf 109B ("Bruno"), was fitted with the 670 PS (660 hp, 493 kW) Jumo 210D engine driving a two-bladed fixed-pitch propeller. During the B-1 production run a variable pitch propeller was introduced and often retrofitted to older aircraft, these were then unofficially known as B-2s. Both versions saw combat with the Condor Legion during the Spanish Civil War, although it was apparent that the armament was still inadequate. Several aircraft were produced with an engine-mounted machine gun but it was very unreliable again, most likely because of engine vibrations and overheating. Thus the Bf 109 V8 was constructed to test the fitting of two more machine guns in the wings. Results showed that the wing needed strengthening. In the following V9 prototype both wing guns were replaced by 20 mm MG FF cannons.
A total of 341 Bf 109B of all versions were built by Messerschmitt, Fieseler, and Erla.
The short-lived Bf 109C ("Caesar") was powered by a 700 PS Jumo 210G engine with direct fuel injection. Another important change was a strengthened wing, now carrying two more machine guns giving four MG 17 in total. The C-0 were pre-production aircraft, the C-1 was the production version, the C-2 an experimental version with an engine-mounted machine gun. The C-3 was planned with 20 mm MG FF cannons replacing the two MG 17 machine guns in the wings but its not known how many C-3 (if any) were built. The C-4 was planned to have an engine mounted MG FF, but the variant was not produced.
A total of 58 Bf 109C of all versions were built by Messerschmitt.
The next model, the V10 prototype, was identical to the V8, except for its Jumo 210G engine. The V10, V11, V12 and V13 prototypes were built using Bf 109B airframes, and tested the DB600A engine with the hope of increasing the performance of the aircraft. However the DB600A was found to be unreliable, and as the improved DB601A was to become available soon, the DB600A was dropped.
Developed from the V10 and V13 prototypes, the BF 109D "Dora" was the standard version of the Bf 109 in service with the Luftwaffe during the period just before World War II. Despite this, the type saw only limited service during the war, as all of the 235 Doras still in service at the beginning of the Polish campaign were rapidly taken out of service and replaced by the Bf 109E, except in some night fighter units, where some examples were used into early 1940. Variants included D-0 and D-1 Models, both with a Junkers Jumo 210D engine and armed with two wing-mounted and two nose-mounted 7.92mm MG 17 machine guns. The D-2 was an experimental version with an engine mounted machine gun but this installation failed again. The D-3 was similar to the C-3 with two 20mm MG FF cannon in the wings.
A total of 647 Bf 109D of all versions were built by Focke-Wulf, Erla, Fieseler, Arado and AGO. Messerschmitt is listed as having only four Bf 109D produced, probably the D-0 preproduction series with the serial production transferred to license manufacturers. Several Bf 109D were sold to Hungary and Switzerland.
To test the new DB601A engine, with its 1,100 PS (1,085 hp, 809 kW), two more prototypes, the V14 and V15, were built, that differed in their armament. While the V14 was armed with the two MG 17 above the engine and one 20 mm MG FF cannon in each wing, the V15 was fitted with just two MG 17s mounted above the engine only. After test fights the V14 was considered more promising and a pre-production batch of 10 BF 109E "Emil" (E-0) was ordered. Batches of both E-1 and E-3 variants were shipped to Spain for evaluation, and received their baptism of fire in the final phases of the Spanish Civil War.
The production version E-1 kept the two 7.92 mm MG 17s above the engine and had two MG 17s in the wings. Later many were modified to the E-3 armament standard. The E-1B was a small batch of E-1s becoming the first operational Bf 109 fighter bomber, or Jagdbomber (usually abbreviated to Jabo). They were fitted with either a ETC 250 bomb rack, carrying one 250 kg bomb or two ETC 50 bomb racks, carrying a 50 kg bomb under each wing. The E-1 was also fitted with the Reflexvisier "Revi" gunsight. Communications equipment was the FuG 7 Funkgerät 7 (radio set) short-range radio equipment, effective to ranges of 30-35 miles.
A total of 1,183 E-1 were built, 110 of them were E-1/B.
The E-2 was not built for unknown reasons, probably another failed attempt to install an engine mounted machine gun or Motorkanone cannon.
To improve the performance of the Bf 109E, the last two real prototypes were constructed, the V16 and V17. They got some structural improvements and stronger armament. These prototypes were the basis of the Bf 109 E-3 version. They were armed with the two MG 17s above the engine and one MG FF cannon in each wing. The E-3 also received additional armour, many receiving self sealing fuel tanks and an optional, improved DB601Aa with 1,175 PS (1,159 hp, 864 kW) respectively.
A total of 1,276 E-3 were built, 75 of them were E-3a export versions without equipment classified as secret.
The E-3 was replaced by the E-4 (with many airframes being upgraded to E-4 standards starting at beginning of the Battle of Britain) which was different in some small details, most notably by the modified MG-FF/M wing cannon and by improved head armor for the pilot. The MG FF/M fired a new and improved type of explosive shell, called Minengeschoß (or 'mine-shell') which was made by drawn steel (the same way brass cartridges are made) instead of being cast as was the usual practice. This resulted in a shell with a thin but strong wall, which had a larger cavity in which to pack a much larger explosive charge than was otherwise possible. The new shell required modifications to the MG FF's mechanism due to the different recoil characteristics, hence the MG FF/M-this special /M designation has also been thought to designate a Motorkanone version of the MG FF cannon.
The canopy was also revised to an easier-to-produce, "squared-off" design, and stayed fairly unchanged until the introduction of welded, heavy framed canopy on the G series in the autumn of 1942. The E-4 would be the base for all further Bf 109 E developments. Some E-4 and later models got a further improved 1,175 PS DB601N high-altitude engine resulting in a slightly changed model number; this E-4/N, first appeared in July 1940. The E-4 was also available as fighter-bomber with equipment very similar to the previous E-1/B. It was known as E-4/B (DB 601Aa engine) and E-4/BN (DB 601N engine).
496 E-4 of all versions were built - 250 E-4, 20 E-4/N, 211 E-4/B and 15 E-4/BN.
The E-5 and E-6 were both reconnaissance variant with a camera installation behind the cockpit. The E-5 was a reconnaissance variant of the E-3, the E-6 was a reconnaissance variant of the E-4/N.
29 E-5s were built and 9 E-6 were ordered.
The E-7 was the next major production variant. It was based on the E-4/B and was able to carry drop tank, which greatly increased their range, or a bomb to be used as fighter-bomber. As the DB 601N was still not available in large numbers many E-7 used a mix of DB 601A, Aa or N engines with the latter designated as E-7/N.
The E-1 and E-4 saw the most heavy action during the Battle of Britain — most of the E-3s were already converted to E-4 standard. The fuel-injected DB601 proved most useful against the British Supermarine Spitfire and Hawker Hurricane, as the British fighters used gravity-fed carburetted engines, which would cut out under negative g forces whereas the DB601 did not. The Bf 109s thus had the initial advantage in dives, either during attack or to escape. The Spitfire proved a formidable opponent, being approximately as fast and allegedly able to out-turn the 109 at medium to high speeds, due to the Bf 109's high wing loading. On the question of comparative turning circles in combat, Spitfires and Hurricanes benefited from their lower wing loading compared with the Bf109; 22 to 24 pounds per square foot on the RAF machines against 32 pounds per square foot for the Bf 109. Royal Aircraft Establishment tests with a captured Bf 109 showed the Spitfire's turning circle — without height loss — was 696 feet (212 m) in radius (the Hurricane's would be slightly tighter) while the 109's was 885 feet (270 m) radius according to British calculations using assumed values as basis. According to the German manuals however, the smallest turning circle was 170 m, and fighter pilots on both sides claim they would out-turn their opponents in combat. Another source states the following:
In roll rates the Bf 109 enjoyed an advantage at dogfight speeds, though at high speeds the manoeuvrability of all three fighters, especially the Spitfire, was severely limited in this regard. The Bf 109 enjoyed good handling near stalling speed.
Firepower was comparable, with the Spitfire and Hurricane having eight .303 inch (7.7mm) machine-guns versus the Bf 109's two 7.92mm MG17s and two 20mm MG FF cannon. However, the MG FF occasionally jammed and had a small (60-round) ammunition capacity. To be fair, when the Spitfires were later upgraded to two 20 mm Hispano-Suiza cannon, the British fighter initially had serious jamming problems with the new weapon. RAF pilots who tested captured Bf 109s liked the engine and throttle response but criticised the high speed handling characteristics, poorer turning circle, greater force required on the control column at speed, and the thick framing of the cockpit glazing which they felt created blindspots in the pilot's field of vision.
In August 1940 comparative trials were held at the E-Stelle in Rechlin, with famous ace Werner Moelders being one of the participants. The tests concluded that the Bf 109 had superior level and climb speed to the Spitfire at all altitudes, but also noted the significantly smaller turning circle of the British fighter. It was advised not to engage into turn-fights unless the performance advantage of the Bf 109 could be used to full effect. The roll rate of the Bf 109 was deemed superior as was its stability on target approach. Moelders himself called the Spitfire "miserable as a fighting aircraft", due to its two-pitch propeller and the inability of its carburettor to handle negative g-forces.
Bf 109E variants and sub-variants
After February 1940 an improved engine, the Daimler-Benz DB 601E, was developed for use with the Bf 109. The engineers at the Messerschmitt facilities took two Bf 109E-1 airframes and installed this new powerplant. The first two prototypes, V21 (Werksnummer (Works number) or W.Nr 5602) and V22 (W.Nr 1800) kept the trapeziform wing shape from the E-1, but the span was reduced by 61 cm (2 ft) by "clipping" the tips. Otherwise the wings incorporated the cooling system modifications described below. V22 also became the testbed for the pre-production DB 601E. The smaller wings had a detrimental effect on the handling so V23, Stammkennzeichen (factory Code) CE+BP, W.Nr 5603, was fitted with new, semi elliptical wingtips. The fourth prototype, V24 VK+AB, W.Nr 5604, flew with the clipped wings but featured a modified, "elbow" shaped supercharger air intake which was eventually adopted for production, and a deeper oil cooler bath beneath the cowling. On all of these prototypes the fuselage was cleaned up and the engine cowling modified to provide improved aerodynamics. The spinner, which was adapted from that of the new Messerschmitt Me 210 was much larger and more rounded.
Development in the shape of the BF109F "Fritz" continued. The rudder was slightly reduced in area and the symmetrical fin section changed to an airfoill shape, which helped increase the effectiveness of the rudder. The conspicuous bracing struts were removed from the horizontal tailplanes which were placed slightly below and forward of their original positions. A semi-retractable tailwheel was fitted and the main undercarriage legs were raked forward by six degrees to improve the ground handling. As the DB601E was not yet available in numbers the pre-production F-0 (the only F variant to have a rectangular supercharger intake) and the first production series F-1/F-2 received the 1,175 hp (875 kW) DB601N engine. The 1,350 hp (1,005 kW) DB601E was first used in the F-3 model together with an enlarged propeller for improved performance.
Externally the Bf 109F had many aerodynamic improvements over the E series. The propeller unit was a three bladed VDM unit 2.96 meters (9 ft 8.5 in) in diameter, slightly smaller than that of the E although the blades were slightly wider. The engine cowling was redesigned to be smoother and more rounded and incorporated a new ejector exhaust arrangement. The supercharger air-intake, still on the left cowling was, from the F-1 series on, a rounded, "elbow" shape which protruded further out into the airstream. On later aircraft the left hand exhaust was fitted with a metal shield to stop exhaust fumes from entering the supercharger intake. Underneath the cowling was a revised, more streamlined oil cooler radiator and fairing. The canopy stayed essentially the same as that of the E-4 although the handbook for the F stipulated that the forward, lower triangular panel to starboard was to be replaced by a metal panel with a port for firing signal flares. Many F-1s and F-2s kept this section glazed. A two-piece, all metal armour plate head shield was added to the hinged portion of the canopy, although some lacked the curved top section. A bullet-resistant windscreen could be fitted to the windscreen as an option.
The wings were redesigned, incorporating revised slats and flaps, along with more streamlined radiator baths. A new cooling system was introduced which was regulated by a system of interconnected variable position flaps which would balance the lowest drag possible with the most efficient cooling possible. A new radiator, shallower but longer than that fitted to the E was developed. A boundary layer duct allowed continual airflow to pass through the airfoil above the radiator ducting and exit from the trailing edge of the upper split flap. The lower split flap was mechanically linked to the central "main" flap, while the upper split flap and forward bath lip position were regulated via a thermostatic valve which automatically positioned the flaps for maximum cooling effectiveness. In 1941 "cutoff" valves were introduced which allowed the pilot to shut down either wing radiator in the event of one being damaged; this allowed the remaining coolant to be preserved. However, these valves were only delivered to frontline units as kits, the number of which, for unknown reasons, was limited. These cutoff valves were never made available for G or K series 109s. Other features of the redesigned wings included new leading edge slats, which were slightly shorter but had a slightly increased chord, and new rounded, removable wingtips which changed the profile of the wings and increased the span slightly over that of the E series.
The redesigned wing made the internal mounting of guns impractical, so armament was revised. The armament of the Bf 109F consisted of the two MG 17 above the engine plus a Motorkanone cannon firing through the propeller hub: The early F versions were equipped with the MG FF/M cannon, the F-2 got the 15 mm MG 151, and from F-4 on the 20 mm MG 151/20 was used. Several aces, particularly Oberst Adolf Galland, criticised the light armament as inadequate for the average pilot. Major Walter Oesau refused to fly an F as long as Emil's were still available. Only after a lack of spare parts, did he accept an F. Later on, an attachment of underwing 20 mm cannons addressed the issue of fire-power, but at a price to performance. Werner Mölders on the other hand saw the single centerline gun as an improvement. It is possible that the criticism of the Bf 109F's armament is based on the early F-2 version with the 15 mm MG 151/15 cannon, which was later replaced by the 20 mm version of the same weapon and was praised for being highly effective by aces like Günther Rall.
The first Bf 109Fs were rushed into service; consequently some aircraft crashed or nearly crashed, with either the wing surface wrinkling or fracturing, or by the tail structure failing. In one such accident, the commander of JG 2 "Richthofen", Wilhelm Balthasar lost his life when he was attacked by a Spitfire during a test flight. While making an evasive manoeuvre, the wings broke away and Balthasar was killed when his aircraft hit the ground. When the wreck was investigated, not a single bullet hole was found. Slightly thicker wing skins and reinforced spars dealt with the wing problems. Tests were also carried out to find out why the tails had failed and it was found that at certain engine settings a high-frequency oscillation in the tailplane spar was overlapped by vibrations from the engine; together this was enough to cause structural failure at the rear fuselage/fin attachment point. Initially two external stiffening plates were screwed onto the outer fuselage on each side and later the entire structure was reinforced.
With these problems out of the way, pilots generally agreed that the F series were the best-handling of all the Bf 109 series. Werner Mölders flew one of the first operational Bf 109F-1s over England from early October 1940; he may well have been credited with shooting down eight Hurricanes and four Spitfires while flying W.No 5628, Stammkennzeichen SG+GW between 11 October and 29 October 1940.
Bf 109F variants and sub-variants
The Bf 109 G "Gustav" series was developed from the F-series airframe although there were several differences. This series used the 1,475 PS Daimler-Benz DB 605. Modifications included reinforced wing structure, an internal bullet-proof windscreen, the use of heavier, welded framing for the cockpit transparencies, and additional light-alloy armour for the fuel tank and armouring of the radiators. It was originally intended that the wheel wells would incorporate small doors to cover the outer portion of the wheels when retracted. To incorporate these the outer wheel bays were squared off. Two small inlet scoops for additional cooling of the spark plugs were added on both sides of the forward engine cowlings. A less obvious difference was the omission of the boundry layer bypass outlets, which had been a feature of the F series, on the upper radiator flaps.
The G-series was designed to adapt to different operational tasks with greater versatility, using field kits known as Rüstsätze. Special high-altitude interceptors with GM 1 high-altitude boost and pressurized cockpits were also produced.
The "new" Daimler-Benz DB 605A series was a development of the DB 601E engine utilised by the preceding Bf 109F-4. This was achieved through increasing the displacement and the compression ratio, as well as other detail improvements. The DB605 suffered from reliability problems during the first year of operation, forcing Luftwaffe units to limit maximum power output to 1,310 PS (975 kW) at 2,600 rpm and 1.3ata manifold pressure, until October 1943, when the full 1475 PS rating at 2800 rpm, 1.42ata manifold pressure was cleared for service use.
The early versions of the Bf 109G closely resembled the Bf 109F-4 and carried the same basic armament - however, as the basic airframe was modified to keep pace with different operational requirements, the basically clean design began to change. From the spring of 1943, the G-series saw the appearance of bulges in the cowling when the 7.92 mm MG 17 was replaced with the 13 mm MG 131 heavy machine guns (G-5 onwards) due to the latter's much larger breechblock, and on the wings (due to larger tyres), leading to the Bf 109G-6s nickname "Die Beule" ("The Bulge"). The Gustav continued to be improved constantly: cockpit visibility, firepower in the form of the 3cm MK 108 cannon was added to the basic design in 1943, and a new, enlarged supercharger for the DB605, an enlarged vertical stabilizer (G-5 onwards), MW-50 power boost in 1944. It has been suggested the added weight of the new engines and heavier armament adversely affected the handling characteristics of the Bf 109, especially since it already had a high wing loading. While technically the statement is true, it is somewhat unfair as analysis show only a modest increase in weight as a result of development, fairly comparable to the development trend with Western Allied fighters.
From the Bf 109G-5 on an enlarged wooden tail unit (identifiable by a taller fin and rudder with a morticed balance tab, rather than the angled shape) was often fitted. This tail unit was standardised on G-10s and K-4s. Although the enlarged tail unit improved handling, especially on the ground, it weighed more than the standard metal tail unit, and required that a counterweight was fitted in the nose, increasing the variant's overall weight.
With the Gustav, a number of special versions were introduced to cope with special mission profiles. Here, long range fighter-reconnaissance and high-altitude interceptors can be mentioned. The former were capable of carrying two 300 litre (66 Imp gal) droptanks, one under each wing, the latter received pressurized cockpits for pilot comfort and GM-1 nitrous oxide "boost" for high altitudes. The latter system was capable of increasing engine output for limited periods by 300 horsepower above the rated altitude and high altitude performance above of that of any Allied fighter in service in 1942-43.
The G-1 was the first of the G-series, starting production in February 1942. This was the first production Bf 109 with a pressurized cockpit and could be identified by the small, horn-shaped air intake for the cockpit compressor just above the supercharger intake on the left upper cowling. In addition the angled armour plate for the pilot's head was replaced by a vertical piece which sealed-off the rear of the side hinged cockpit canopy. Small, triangular armour-glass panels were fitted into the upper corners of this armour, although there were aircraft in which the plate was solid steel. Silica gel capsules were placed in each pane of the windscreen and opening canopy to absorb any moisture which may have been trapped in the double glazing. The last 80 G-1s built were lightweight G-1/R2s. In these GM-1 nitrous oxide 'boost' was used, and the pilot's back armour was removed, as were all fittings for the long range drop tank. A few G-1s flown by I./JG 1 are known to have carried the underwing, MG 151/20E 20mm cannon gondolas..
The G-2, which started production in May 1942 lacked the pressurization and GM-1 installation . The canopy reverted to one layer of glazing and incorporated the angled head armour used on the F-4, although several G-2s had the vertical type of the G-1. Several Rüstsätze could be fitted, although installing these did not change the designation of the aircraft. Instead the /R suffix referred to the G-2s Rüstzustand or equipment condition of the airframe, which was assigned at the factory, rather than in the field. There were two Rüstzustand planned for G-2s:
The rack and internal fuel lines for carrying a 300 litre drop-tank were widely used on G-2s, as were the underwing MG 151/20 cannon gondolas. Several G-2s were fitted with the ETC 500 bomb rack, capable of carrying one 250 kg bomb. The final G-2 production batches built by Erla and Messerschmitt Regensburg were equipped as tropical aircraft (often referred to as G-2 trop), equipped with a sand-filter on the front of the supercharger intake and two small, teardrop shaped metal brackets on the left side of the fuselage, below the cockpit sill. These were used as mounts for specially designed sun umbrellas (called Sonderwerkzeug or Special tool), which were used to shade the cockpit.
167 G-1s were built between February and June 1942, and 1586 G-2s between May 1942 and February 1943; one further G-2 was built in Győr, Hungary, in 1943. Maximum speed of the G-2 was 537 km/h at sea level and 660 km/h at 7,000 m rated altitude with the initial – reduced – 1.3ata rating. Performance of the G-1 was similar, but above rated altitude the GM-1 system could be used for additional performance: 680 km/h could be achieved at 12,000 meters.
In September 1942 the G-4 appeared. It was identical to the G-2 in all respects, including performance, except that the much improved FuG 16 V.H.F. radio set was fitted. Up to July 1943, 1,242 G-4s were produced, and an additional 4 were produced in Győr and WNF factories in the second half of 1943. A pressurized version, G-3 was also produced, being identical to the G-1 in all except its V.H.F. radio set FuG 16. Only 50 were produced between January-February 1943.
In February 1943 the G-6 was introduced with the 13 mm MG 131s, replacing the smaller 7.92 mm MG 17 - externally this resulted in two sizeable blisters over the guns. These bulges reduced speed by nine km/h.
Over 12,000 examples were built well into 1944; the exact number being impossible to ascertain due to numerous variants and rebuilds. The G-5 was identical to the G-6 with pressurized cockpit, and of which 475 examples were built between May 1943 and August 1944. The G-5/AS was the first to be equipped with a DB 605AS engine for high altitude missions. GM-1-boosted G-5 and G-6 variants received the additional designation of /U2.
The G-6/U4 variant was armed with a 30 mm MK 108 cannon mounted as a Motorkanone shooting through the propeller hub instead of the 20 mm MG 151/20. The G-6 was very often seen during 1943 fitted with assembly sets, used to carry bombs or a drop tank, for use as night-fighter, or to increase fire power by adding rockets or extra gondola guns. During 1943, a number of improvements were gradually introduced for the type's benefit: armoured glass head-rest ("Galland Panzer") (early 1943), and the introduction of the clear-view "Erla Haube" canopy (autumn 1943) improved visibility, especially to the rear, and a taller tail unit improved stability at high speeds. The introduction of the WGr. 21 cm under-wing mortar/rockets and the 30 mm MK 108 cannon increased firepower. Certain production batches of the Gustav were fitted with aileron Flettner tabs to decrease stick forces at high speeds. Advanced radio/navigational equipment was also introduced. Subsequent Bf 109G versions were basically modified versions of the G-6. Early in 1944, new engines with larger superchargers for improved high-altitude performance (DB 605AS), or with MW-50 water injection for improved low/medium altitude performance (DB 605AM), or these two features combined (DB 605ASM) were introduced into Bf 109 G-6. Maximum speed of the G-5/G-6 was 500-510 km/h at sea level, 625-630 km/h at 6,600 m-rated altitude using the restricted 1.3ata boost, and when using the full 1.42ata boost 530 and 640 km/h respectively. Figures are without MW-50 or GM-1 boost.
The G-8 was a dedicated recon version based on the G-6. The G-8 had often only the Motorkanone engine cannon or the cowling machine guns installed and there were several subversions for short or long range recon missions with a wide variety of recon cameras and radios available for use.
The G-14, appearing in mid-1944 was basically a late-war Bf 109 G-6 with the aforementioned improvements standardized, and with MW 50 methanol/water injection increasing output to 1800 hp being a standard fitting. High-altitude models of the G-14 received the DB 605ASM engine and were named G-14/AS. There was increasing tendency to use wood on some less vital parts (e.g. on a taller tailfin/rudder unit, pilot seat or instrument panel) - not because of the shortage of strategic materials like aluminium as often suggested, but as it allowed freeing up metalworking capacity by involving of the woodworking industry of more parts.
The G-10 was an attempt to match the proven Bf 109 G-6/G-14 airframe with the new and more powerful DB 605D engine with minimal disruption of the production lines. Despite what the designation would suggest, it appeared in service after the G-14 and somewhat the K-4 in November 1944. Early production G-10s used fuselages taken from the G-14 production lines, this was probably a source of confusion as many authors still believe many G-10 were based on recycled G-series fuselages. The most recognizable change was the standardized use of the "Erla-Haube" canopy, sometimes referred to (incorrectly) as the "Galland" hood. This canopy improved the pilot's view by reducing the number of support struts, which was often criticized before. The G-10 was produced in very substantial numbers, with some 2,600 G-10s produced until the war's end. The Bf 109 G-10, AS-engined G-5s, G-6s and G-14s as well as the K-4 saw a refinement of the bulges covering the breeches of the cowl mounted MG 131, these taking on a more elongated and streamlined form, barely discernible on the upper sides of the cowl panels, as the large engine supercharger required a redesign of the cowling.
A similar varying product was the Bf 109 G-12. This was a two-seat trainer version of the Bf 109 and was rarely armed with anything more than the two cowling machine guns. The space needed for the second cockpit was gained by reducing the internal fuel capacity to only 240 l thus they nearly always used the 300 l drop tank as standard equipment. The G-12 was built using a wide variety of G-series fuselages, many were G-2 based but several were built of rebuilt/repaired G-1, G-4 and G-6.
Bf 109G subtypes and variants
The base subtypes could be equipped with a Rüstsatz add-on standard field kits, in practice this meant hanging on some sort of additional equipment like droptanks, bombs or cannons to standard attachment points, present on all production aircraft. Aircraft could be modified in the factory with Umrüst-bausatz (Umbau) conversion kits or by adding extra equipment, designated as Rüstzustand, to convert standard airframes for special roles - a reconnaissance fighter or bad-weather fighter, for example. Unlike the Rüstsatz field-kits these modifications were permanent.
The Rüstsatz-kits were designated by the letter R and a Roman number. Rüstsatz-kits did not alter the aircraft's designation, so a Bf 109G-6 with Rüstsatz II (50 kg bombs) remained designated as Bf 109G-6, and not 'G-6/R2' - the G-6/R2 was a reconnaissance fighter with MW 50 - as suggested by most of the publications. The Umrüst-bausatz, Umbau. or Rüstzustand were identified with either an /R or /U suffix and an Arab number, i.e. Bf 109 G-10/U4.
Common Rüstsatz kits, Bf 109G
Common Umrüst-Bausatz [Umbau] numbers
Known Variants
Fictional Variants
The Bf 109H was intended to be a high-altitude fighter, developed from the F-series. The wingspan was increased to 11.92 m, the stabilizer again received a strut leading to the fuselage, and it was also widened. Maximum speed was 750 km/h at 10,100 m. A small number of Bf 109H-1s were built, flying several sorties over Britain and France. Bf 109 H-2 and H-5 developments were also planned, before the entire H-series was scrapped because of wing flutter problems.
Most of the Bf 109K "Kurfürst" series saw duty. This series was the last evolution of the Bf 109. The K series was a response to the bewildering array of series, models, modification kits and factory conversions for the Bf 109, which made production and maintenance complicated and costly — something Germany could ill-afford late in the war. The RLM ordered Messerschmitt to rationalise production of the Bf 109, consolidating parts, types, and so on, to produce a uniform, standard model with better interchangeability of parts and equipment. This was to have started in the later models of the G series, but things went in quite the opposite direction. The RLM told Messerschmitt, in effect, to try harder, and the K series was born. Work on the new version began in 1943, and the prototype was ready by the autumn of that year. Series production started in August 1944 due to delays with continuous changes and the new DB605D powerplant. Operational service began in October 1944, and approximately 200 were delivered to frontline units by the end of the month. By the end of January 1945, despite continuous heavy fighting, over 300 K-4s — about every fourth 109 — were listed on hand with the 1st line Luftwaffe units.
In the proposed K-6, K-8, K-10 and the K-14 the armament would have seen some changes. They retained the two MG 131 above its engine and added a built-in MK 108 in each wing and a MK 108 Motorkanone engine mounted cannon. The K-14 would have had the special performance DB605L and four bladed propeller.
Only the K-4 saw action in numbers, with approximately 1,700 being delivered by factories before the end of hostilities. K-4s with quasi-DB605Ls, a DB605 with the two-stage super-charger but not other improvements, and the standard three-bladed propellers, were assembled. Armament of the K-4 consisted of a 30 mm MK 108 engine-mounted cannon with 65 rounds and two 13 mm MG 131s in the nose with 300 rounds each, and there was the capacity to carry additional equipment such as a droptank, bombs up to 500 kg, underwing 20 mm cannon gondola pods or 210 mm Wfr.Gr. 21 rockets (as on the Gustav models); the latter two however were rarely used due to marauding Allied fighters necessitating maintaining high speed capability.
Some sources point to limited use of the K-14, but the type was never actually built. The K-14 it is believed, would have been powered by the DB 605L, reached 460mph and achieved an operational altitude of 38,000 ft. The armament would not have been as powerful as the K-10 (intended as a bomber-destroyer) and included only two wing-mounted 15mm MG 151s, two fuselage-mounted MG 131s and the MK 103 cannon fired through the propeller shaft.
The Bf 109 K-4 was the fastest 109 of world War II, reaching about 715 km/h (445 mph) at 7,500 m altitude; improved propellers were being developed when the war ended which would boost the speed to 727 km/h (452 mph), or even 741 km/h (460 mph). Rate of climb was outstanding, up to 5,800 ft (1,770 m)/min at 1.98 ata, and 5,500 ft (1,680 m)/min at 1.8 ata. With such improvements in performance, the Bf 109 remained comparable to the highest performance opposing fighters until the end of the war. However, the deteriorating ability of the thousands of novice Luftwaffe pilots by this stage of the war meant the 109's strengths were of little value against the numerous and well-trained Allied fighter pilots.
The Bf109T "Träger" version was developed as a carrier based version. Prior to the war the German Navy had become fascinated with the idea of the aircraft carrier.. Borrowing ideas from the British and Japanese (mainly Akagi), they started the construction of Graf Zeppelin as part of the rebuilding of the navy. The air group for the carrier was settled on Messerschmitt Bf 109T fighters and Ju 87T dive bombers. The suffix 'T' denotes carrier, 'Träger', in German use.
Initially 10 Bf 109E-3s were ordered to be modified to a Bf 109T-0 standard. This included, adding a tail-hook, catapult fittings, structural strengthening, manually folding wings and increased wingspan (to 11.08 m). Also the landing gear track was a little wider.
Following flight tests, especially the catapult tests, a series of 70 T-1s with DB601Ns was to be produced at Fieseler in Kassel, but after seven T-1s were built, the carrier project was canceled. The remaining 63 of 70 T-1s were built as T-2s without carrier equipment and some of the T-0 and T-1s may have been "upgraded" to T-2 standard. These fighters were assigned to I/JG.77, deployed in Norway. The decision to base them in Norway was made primarily by the conditions on the Norwegian landing strips. These landing strips were both short and subject to frequent, powerful cross-winds. Some time after the unit was ordered to turn over their aircraft to a test unit that was training on the Drontheim-Fjorde strip and received E-3s as replacements. The armament of the Bf 109T consisted of two MG 17 above the engine and one MG FF/M cannon in each wing.
Interest in Graf Zeppelin revived when the value of aircraft carriers became obvious, and in 1942 the ship was back in the yards for completion. By this time the Bf 109T was hopelessly outdated and a new fighter would be needed. Messerschmitt responded with the updated Me 155A series, but work on the ship was again canceled and the Me 155 was later re-purposed as a high-altitude interceptor.
Finally plans for a high flying high speed version, the Bf109Z "Zwillling" were also in the pipe line by wars end. This experimental aircraft was essentially two Bf 109F airframes (together with outer wing panels) joined together by means of a new wing, and new tail section, in a manner paralleled by the F-82 Twin Mustang. Two variants of this aircraft were proposed, one an interceptor armed with five 30 mm cannons, the other a fighter-bomber with a 1,000 kg bomb load. Only one Bf 109Z was built, and it was never flown, having been damaged in an Allied bombing raid while in hangar and the project was permanently abandoned in 1944.
The very first Bf109 V1 prototype, D-IABI as she flew from Augsburg-Haunstettenon the 28th of May 1935. Note the bulbous nose, thus constructed to accomodate the Rolls Royce Kestrel power plant.