1936 heavy fighter family by Messerschmitt
The Messerschmitt Bf 110, often known unofficially as the Me 110, is a twin-engined (destroyer, heavy fighter), fighter-bomber ("Jagdbomber" or "Jabo"), and night fighter ("Nachtjäger") designed by the German aircraft company Bayerische Flugzeugwerke (BFW) and produced by successor company Messerschmitt. It was primarily operated by the "Luftwaffe" and was active throughout the Second World War.
Development of the Bf 110 commenced during the first half of the 1930s; one early proponent of the type was Hermann Göring, who believed its heavy armament, speed, and range would make it the premier offensive fighter of the "Luftwaffe". Early variants were armed with a pair of MG FF 20 mm cannon, four 7.92 mm (.323 in) MG 17 machine guns, and one 7.92 mm (.323 in) MG 15 machine gun for defence (later variants would replace the MG FFs with MG 151s and the rear gunner station would be armed with the twin-barreled MG 81Z). Development work on an improved type to replace the Bf 110 - the Messerschmitt Me 210 - began before the conflict started, but its shakedown troubles resulted in the Bf 110 soldiering on until the end of the war in various roles. Its intended replacements, the aforementioned Me 210 and the significantly improved Me 410 "Hornisse", never fully replaced the Bf 110.
The Bf 110 served with considerable success in the early campaigns in Poland, Norway, and France. The primary weakness of the Bf 110 was its lack of manoeuvrability, although this could be mitigated with better tactics. This weakness was exploited by the RAF, when Bf 110s were flown as close escort to German bombers during the Battle of Britain. When British bombers began targeting German territory with nightly raids, some Bf 110-equipped units were converted to night fighters, a role to which the aircraft was well suited. After the Battle of Britain, the Bf 110 enjoyed a successful period as an air superiority fighter and strike aircraft in other theatres and defended Germany from strategic air attack by day against the United States Army Air Forces (USAAF)'s Eighth Air Force, until an American change in fighter tactics rendered them increasingly vulnerable to developing American air supremacy over the Reich as 1944 began.
During the Balkans and North African campaigns and on the Eastern Front, the Bf 110 rendered valuable ground support to the German Army as a potent fighter-bomber. Later in the conflict, it was developed into a formidable radar-equipped night fighter, becoming the principal night-fighting aircraft of the "Luftwaffe". The majority of the German night fighter aces flew the Bf 110 at some point during their combat careers and the top night fighter ace, Major Heinz-Wolfgang Schnaufer, flew it exclusively and claimed 121 victories in 164 sorties. In addition to its use by the "Luftwaffe", other operators of the type included the Hungarian Air Force, the "Regia Aeronautica", and the Romanian Air Force.
Design and development.
Genesis and competition.
Throughout the 1930s, the air forces of many major military powers were engaged in a transition from biplane to monoplane designs. Most concentrated on the single-engined fighter aircraft, but the problem of range arose. The Ministry of Aviation (RLM, for "Reichsluftfahrtministerium"), at the encouragement of Hermann Göring, issued a request for a new multipurpose fighter called the "Kampfzerstörer" (battle destroyer) with long range and an internal bomb bay. This request called for a twin-engined, three-seat, all-metal monoplane that was armed with cannon and a bomb bay. Of the seven companies approached, only Bayerische Flugzeugwerke (which later became "Messerschmitt"), Focke-Wulf, and Henschel responded to the request.
The Focke-Wulf design, the Focke-Wulf Fw 57, had a wingspan of 25.6 m (84 ft) and was powered by a pair of DB 600 engines. It was armed with two 20 mm MG FF cannons in the nose, while a third was positioned in a dorsal turret. The Fw 57 V1 flew in 1936, but its performance was poor and the machine crashed. The Henschel Hs 124 was similar in construction layout to the Fw 57, equipped with two Jumo 210C for the V1. The V2 used the BMW 132Dc radial engines generating 870 PS compared with the 640 PS Jumo. The armament consisted of a single rearward-firing 7.92 mm (.312 in) MG 15 machine gun and a single forward-firing 20 mm MG FF cannon.
Bayerische Flugzeugwerke omitted the internal bomb load requirement from the RLM directive to increase the armament element of the RLM's specification. The Bf 110 proved to be far superior to its rivals in providing the speed, range, and firepower to meet its role requirements. Accordingly, Bayerische Flugzeugwerke's submission bested Focke-Wulf, Henschel, and Arado, and thus the firm was given the funds to build several prototype aircraft. By the end of 1935, the Bf 110 had evolved into an all-metal, low-wing cantilever monoplane of semimonocoque design featuring twin vertical stabilizers and powered by two DB 600A engines. The design was also fitted with Handley-Page wing slots (actually, leading-edge slats).
Early variants.
By luck (and pressure by Ernst Udet), the RLM reconsidered the ideas of the "Kampfzerstörer" and began focusing on the "Zerstörer". Due to these changes, the Bayerische Flugzeugwerke design better fit the Ministry's requests. On 12 May 1936, Rudolf Opitz flew the first Bf 110 from Augsburg. As many pre-war designs found, the engine technologies promised were of insufficient reliability. Even with the temperamental DB 600 engines, the RLM found that the Bf 110, while not as manoeuvrable as desired, was rather faster than its original request specified, as well as faster than the front-line fighter, the Bf 109 B-1. The order for four pre-production A-0 units was promptly placed, the first of which was delivered in January 1937. Amid this phase of testing, both the Focke-Wulf Fw 187 and Henschel Hs 124 competitors were rejected and the Bf 110 was ordered into full rate production.
The initial deliveries of the Bf 110 encountered several delays with their DB 600 engines, which forced Bayerische Flugzeugwerke to install Junkers Jumo 210B engines, leaving the Bf 110 seriously underpowered and able to reach a top speed of only 431 km/h (268 mph). The armament of the A-0 units was also limited to four nose-mounted 7.92 mm (.312 in) MG 17 machine guns. Even without delivery of the DB 600 engines, Bayerische Flugzeugwerke began assembly of the Bf 110 in mid-1937. As the DB 600 engines continued to have problems, Bayerische Flugzeugwerke was forced to keep on using Jumo motors, the 210G, which supplied 515 kW (700 PS) each (versus the 471 kW/640 PS supplied by the 210B). Three versions of the Bf 110B were built, the B-1, which had four 7.92 mm (.312 in) MG 17 machine guns and two 20 mm MG FF cannons, the B-2 reconnaissance version, which had a camera in place of the cannons and the B-3, which was used as a trainer, with the cannons replaced by extra radio equipment. Only 45 Bf 110Bs were built before the Jumo 210G engine production line ended. The major identifier of the -A and -B-series Bf 110s was the very large "mouth" bath radiators located under each engine.
In late 1938, the DB 601 B-1 engines became available in quantity, and thus were promptly adopted on the Bf 110C. In the adoption of this engine, the design teams opted to remove the radiators under the engine nacelles and replace them with water/glycol radiators for the C-series airframes, placing them under the wing just outboard of each nacelle, otherwise similar in installation, appearance and function to those on the Bf 109E. With the DB 601 engine, the Bf 110's maximum speed increased to with a range around . A compact oil cooler and air scoop remained under each engine nacelle for the remainder of the Bf 110's production run.
First conceived in the latter half of 1939, the Bf 110D featured a series of modifications and improvements that were focused on increasing its range. The initial D-series version, the Bf 110D-0 was designed to add a large, streamlined, 1,050-litre (277 U.S. gallon) ventral fuel tank built under the fuselage, which required a substantially sized, conformal streamlined ventral fuselage fairing extending from halfway back under the nose to the rear of the cockpit glazing, inspiring the nickname "Dackelbauch" (dachshund's belly). The D-1 was also set up to accept a pair of fin-equipped 900-litre (238 U.S. gallon) drop tanks, one under each wing, increasing the total fuel capacity to 4,120 litres (1,088 U.S. gallons). The substantial added drag of the early "dachshund's belly" ventral fuselage tank in test flights mandated its omission from production D-1s, although they were still prepared to mount an improved, better-streamlined, version. D-1s so equipped were known as D-1/R1, whereas the D-1/R2 was equipped with two 900-litre drop tanks and a droppable 85-litre oil tank. Later D-2 and D-3 versions retained the twin underwing 900-litre drop tank capability, using multipurpose ordnance racks capable of holding either drop tanks or carrying bombs.
Later production variants.
The production of the Bf 110 was put on a low priority in 1941 in expectation of its replacement by the Me 210. During this time, two versions of the Bf 110 were developed, the E and F models. The E was designed as a fighter bomber ("Zerstörer Jabo"), able to carry four 50 kg (110 lb) ETC 50 racks under the wing, along with the centreline ETC 500 bomb rack. The first E, the Bf 110 E-1 was originally powered by the DB 601B engine, but shifted to the DB 601P as they became available in quantity. In total, 856 Bf 110E models were built between August 1940 and January 1942. The E models also had upgraded armour and some fuselage upgrades to support the added weight. Most pilots of the Bf 110E considered the aircraft slow and unresponsive, with one former Bf 110 pilot commenting the E was "rigged and a total dog."
The Bf 110F featured the new DB 601F engines, which produced 993 kW/1,350 PS (almost double the power the original Jumo engines provided), which allowed for upgraded armour, strengthening, and increased weight with no loss in performance. Three common versions of the F model existed. Pilots typically felt the Bf 110F to be the best of the Bf 110 line, being fully aerobatic and in some respects smoother to fly than the Bf 109, though not as fast. Eventually, 512 Bf 110F models were completed between December 1941 and December 1942, when production gave way to the Bf 110G.
Bf 110G production details.
Although the Me 210 entered service in mid-1941, it was plagued with problems and was withdrawn from service for further development. In the wake of the failure of the Me 210, the Bf 110G was designed. The G model was fitted with DB 605B engines, producing 1,085 kW (1,475 PS) at their "Notleistung" (war emergency) top-level setting, and 997 kW (1,355 PS) at 5.8 km (19,000 ft) altitude. The Bf 110G also had upgraded nose armament, and underwent some changes which improved the aerodynamics of the aircraft. The rear cockpit access was moved forward from the transversely-hinged, "tilt-open" rearmost canopy glazing to a side/top hinged opening section of the main canopy, opening to port, with a new rearmost framed glazing section fixed in place. No Bf 110 G-1 existed, so the Bf 110 G-2 became the baseline Bf 110G. A large number of "Rüstsätze" field conversion packs were available, making the G subtype the most versatile production version of the Bf 110.
The initial batch of six preseries production G-0 aircraft built in June 1942 were followed by 797 G-2, 172 G-3 and 2,293 of the night fighter-dedicated, three-seater G-4 models; built between December 1942 and April 1945. Pilots reported the Bf 110G to be a "mixed bag" in the air, in part due to all changes between the G and F series. The Bf 110G was considered a superior gun platform with excellent all-around visibility, and considered, until the advent of the Heinkel He 219, to be one of the best night fighters flown by the "Luftwaffe".
Armament.
The Bf 110's main strength was its ability to mount unusually powerful air-to-air weaponry. Early versions had four 7.92 mm (.312 in) MG 17 machine guns in the upper nose and two 20 mm MG FF/M cannons fitted in the lower part of the nose. Later versions replaced the MG FF/M with the more powerful 20 mm MG 151/20 cannons and many G-series aircraft, especially those which served in the bomber-destroyer role, had two 30 mm (1.18 in) MK 108 cannons fitted instead of the MG 17. The defensive armament initially consisted of a single, flexibly