The Heinkel He 219 ''Uhu'' ("Eagle-Owl") was a night fighter that served with the German Luftwaffe in the later stages of World War II. A relatively sophisticated design, the He 219 possessed a variety of innovations, including Lichtenstein SN-2 advanced VHF-band intercept radar, also used on the Ju 88G and Bf 110G night fighters. It was also the first operational military aircraft to be equipped with ejection seats and the first operational German World War II-era aircraft with tricycle landing gear. Had the ''Uhu'' been available in quantity, it might have had a significant effect on the strategic night bombing offensive of the Royal Air Force but only 294 of all models were built by the end of the war and these saw only limited service.〔Boyne 1997, p. 330.〕
==Design and development==
Development and production of the He 219 was protracted and tortuous, due to political rivalries between Josef Kammhuber, commander of the German night fighter forces, Ernst Heinkel, the manufacturer and Erhard Milch, responsible for aircraft construction in the ''Reichsluftfahrtministerium'' (RLM — the German Aviation Ministry). The aircraft was also complicated and expensive to build; these factors further limited the number of aircraft produced.
When engineer Robert Lusser returned to Heinkel from Messerschmitt, he began work on a new high-speed bomber project called P.1055. This was an advanced design with a pressurized cockpit, twin ejection seats (the first to be planned for use in any combat aircraft), tricycle landing gear (featuring a nose gear that rotated its main strut through 90° during retraction, to fit flat within the forward fuselage) and remotely controlled defensive gun turrets similar to those used by the Messerschmitt Me 210. Power was to be provided by two DB 610 "coupled" engines then under development, weighing on the order of about tonnes apiece, producing (2,200 kW/2,950 hp) each, delivering excellent performance with a top speed of approximately 750 km/h (470 mph) and a 4,000 km (2,500 mi) range with a 2,000 kg (4,410 lb) bomb load.
The RLM rejected the design in August 1940 as too complex and risky. Lusser quickly offered four versions of the fighter with various wingspans and engine choices in order to balance performance and risk. At the same time, he offered the P.1056 a night fighter with four 20 mm cannons in the wings and fuselage. The RLM rejected all of these on the same grounds in 1941. Heinkel was furious and fired Lusser on the spot.
About the same time as Lusser was designing the P.1055, Kammhuber had started looking for an aircraft for his rapidly growing night fighter force. Heinkel quickly re-designed the P.1055 for this role as the P.1060. This design was similar in layout but somewhat smaller and powered by two of the largest displacement (at 44.5 litres/2,700 cu. in.) liquid-cooled aviation engines placed in mass production in Germany, the DB 603 inverted V12 engine, using annular radiators similar to the ones on the Jumo 211-powered Junkers Ju 88 A but considerably more streamlined in appearance. The engine had poor altitude performance, which was a problem for Heinkel's short-winged design but Daimler had a new "G" version under development to remedy the problem. Heinkel was sure he had a winner and sent the design off to the RLM in January 1942, while he funded the first prototype himself. The RLM again rejected the He 219 in favour of new Ju 88- and Me 210-based designs.
Construction of the prototype started in February 1942 but suffered a serious setback in March, when Daimler said that the DB 603G engine would not be ready in time. Instead, they would deliver a 603A engine with a new gear ratio to the propellers, as the DB 603C with the choice of using four-blade propellers, as the similarly-powered Fw 190C high-altitude fighter prototypes were already starting to use into early 1943, with the DB 603.〔Wagner and Nowarra 1971, p. 246.〕 DB 603 engines did not arrive until August 1942 and the prototype did not fly until 6 November 1942.〔Green and Swanborough 1989, p. 12.〕 When Kammhuber saw the prototype on the 19 November, he was so impressed he immediately ordered it into production over Milch's objections. Milch—who had rejected the He 219 in January—was enraged.
Stability problems with the aircraft were noted but Heinkel overcame these by offering a cash prize to engineers who could correct them. Further changes were made to the armament during the development of the prototype He 219V-series. the dorsal rear defensive guns—mounted atop the fuselage and firing directly rearward from a fixed, internally mounted, rear-facing dorsal "step" position, at a point just aft of the wing trailing edge—were removed due to their ineffectiveness. The forward-firing armament was increased to two 20 mm cannons in the wing roots, inboard of the propeller arcs to avoid the need for gun synchronizers, with four more guns mounted in the ventral tray, which had originally ended in a rearwards-facing "step" similar to and located directly under the deleted rear dorsal "step"—this rearwards-facing feature was also deleted for similar reasons. The A-0 model featured a bulletproof shield, that could be raised in the front interior cockpit, hiding the entire bottom portion of the windscreen, providing temporary pilot protection and leaving a sighting slot by which the gunsight could be aimed at a bomber. Production prototypes were then ordered as the He 219 A-0 and quickly progressed to the point where V7, V8 and V9 were handed over to operational units in June 1943 for testing.
The earlier prototypes, with four-blade propellers for their DB 603 engines (also used on the Fw 190C prototypes, with the same DB 603 engine) had metal nose cones designed to use the quartet of forward-projecting masts for the ''Matratze'' 32-dipole radar antennae on the noses of at least the first five prototypes], used with the early UHF-band Lichtenstein radar installation.〔("Heinkel He 219." ) ''Livevehicles.com''. Retrieved: 23 April 2015.〕 These early He 219V-series prototype airframes also had cockpit canopies that did not smoothly taper aftwards on their upper profile, as on the later production He 219A-series airframes, but instead ended in a nearly hemispherically-shaped enclosure.〔("Heinkel He 219." ) ''falkeeins.blogspot.com'', November 2010. Retrieved: 23 April 2015.〕 The "V4" (fourth) prototype had a small degree of internal metal framing in the rearmost hemispherical canopy glazing, apparently for a rear dorsal weapons mount or sighting gear for the deleted fixed "step"-mount rearwards-firing armament. The idea for the rear-facing dorsal and ventral "step" features on the original He 219 fuselage design, for armament emplacement locations was later carried into the May 1943 revised fuselage design, for what became the Heinkel ''Amerika Bomber'' design contract competitor, the He 277, as its ultimate design (general arrangement ''Typenblatt'' drawings ) show the early He 219 V-series "steps" being inherited by the He 277 revised fuselage design, in similar locations on its fuselage, with the ventral emplacement only moved rearwards by two meters, to provide space for the seven-meter long bomb bay. The adopted "step" locations provided for the ''Amerika Bomber's'' dorsal and ventral rearwards-firing aft fuselage turrets, with each turret placed at the position of the "step" features, being armed with a pair of MG 151/20 cannon apiece.〔Griehl and Dressel 1998, p. 159.〕 Milch repeatedly tried to have the He 219 program cancelled and in the process, Kammhuber was removed from office. Production ceased for a time but was restarted because the new Junkers Ju 388s were taking too long to get into service.
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