TYPE: Night- and bad-weather fighter

ACCOMMODATION:  Pilot and radar-operator/navigator

POWER PLANT: Two Daimler-Benz DB 603g liquid-cooled engines, rated at 1,726 hp each

PERFORMANCE: 472 mph at 27.800 ft

COMMENT: As early as 1940, the Messerschmitt design bureau concerned itself with the idea of fusing two fighters into a single airframe to provide a considerable increase in range and payload. The work was based on a RLM edict to simplify the number of combat aircraft to a few basic models.
Known as Messerschmitt Me 109Z Zwilling (twin) and Messerschmitt Me 609, the layouts were primarily intended as Zerstörer (Destroyer), Schnellbomber (Fast bomber or Nachtjäger (Night fighter). Following detailed examinations, the most suitable solution capable of early production indicated the use of a Daimler-Benz DB 605A-powered Messerschmitt Me 109G. A considerable performance increase, however, was to be expected if  2,000 hp Junker Jumo 213 engines were installed, requiring only a few alteration to incorporate complete major components of the standard aircraft. The modifications were limited mainly to the need of a completely new constant –cord wing center section and tailplane that simplified manufacture. Besides relocation of the undercarriage attachment points and the use of larger wheels, the ailerons and outboard leading-edge slots were lengthened and auxiliary fuel tanks were installed. In the course of development work on the twin aircraft, the Messerschmitt Me 309 was also considered and resulted in the Messerschmitt Me 609 destroyer, fast bomber and night fighter. The more powerful engine intended for the Messerschmitt Me 609 led to improvements in flight performance.
For the Night fighter version a FuG 217V/R “Neptun” radar with smal “Hirschgeweih” (Stag’s Antlers) aerial array was provided. These were mounted at the wingtips close to the leading edge. When all work on the unsuccessful Messerschmitt Me 309 was stopped all further effort on the Me 609 was cancelled (Ref.: 24).

TYPE: Night Fighter

ACCOMMODATION: Crew of three

POWER PLANT: Two Junkers Ju 222 liquid-cooled radial engines, rated at 2,500 hp each, resp. two Daimler-Benz DB 603 liquid-cooled engines, rated at 1,900 hp each

PERFORMANCE: 435 mph

COMMENT: 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 Junkers Ju 88G and the Messerschmitt 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; however, only 294 of all models were built by the end of the war and these saw only limited service
By the end of 1944, the Luftwaffe had accepted 214 Heinkel He 219As, but during the previous November, the promulgation oft he „Jäger-Notprogramm“ (Fighter Emergency Programme) had sounded death knell for all twin piston-engine fighters with the sole exception of the Dornier Do 335 Pfeil. Ernst Heinkel tacitly ignoring the RLM edict and finalized an assembly line for the fighter at Oranienburg.
Prior to the creation of the „Jäger-Notprogramm“ several variants of the basic He 219 had reached advanced development and even initial production stages. The follow-on series to the He 219As in service was to be the He 219B fitted with the new, but troublesome 2,500 hp Junkers Jumo 222A/B 24 cylinder engines – a multibank, liquid-cooled inline engine, with six rows of cylinder blocks having four cylinders each—which would have allowed the He 219 to reach 440 mph, each of which were almost the same displacement in their A/B (supercharged) and E/F (supercharged with intercoolers) versions and each only very slightly heavier, compared to the Pratt & Whitney R-2800 Double Wasp radial engines in the American Northrop P-61 „Black Widow“ night fighter. The He 219B wing was also to have had an increased span of 22.06 m for better high altitude performance. The Jumo 222 did not reach production status, with just under 300 examples built in at least three differing displacement sizes. Only a few test machines were ever fitted for the engines; some additional air frames were built with the enlarged wing. These examples were slated to fly with high-altitude versions of the standard DB 603 powerplants in place of the troubled Jumo 222 multibank powerplants, but only one or two test machines ever flew with them.
It was proposed to install the Junkers Jumo 222 in a high-altitude three-seat model, the Heinkel He 219B-1, but the non-availability of the Junkers engine necessitated the installation of the Daimler-Benz DB 603Aa in a sole exemple of this variant completed and tested. This He 291B-1 had an aerodynamically refined cockpit canopy, a lengthened fuselage, and an extended wing spanning. Flight testing was cut short when, during the second landing, the starboard undercarriage leg collapsed and the aircraft suffered such intensive damage that it had to be scrapped.
The second B-series, the Heinkel He 219B-2, was intended specifically for anti-Mosquito operations, and was similar in concept of the He 219A-6 in being stripped of virtually all armor.  Employing an He 219A-5 two-seat fuselage married to a long-span B-series wings it was powered by Daimler-Benz DB 603 engines with TK 13 turbo-superchargers, but only few additionally aircraft of this type were hurriedly completed. These were placed in operational service with a forward-firing armament of two 20-mm MG 151 cannon in the wing roots, and  two 30-mm MK 108 cannon  in a „Schräge Musik“ installation.
The Heinkel He 219B-3 was similar to its predecessor apart from the reinstatement of ventral tray armament comprising two 30-mm MK 108 and two 20-mm MG 151 cannon, and this, too, was to have been powered by two Daimler-Benz DB 603L engines, but while still under construction, Heinke received  a directive from the Technischen Amt to await delivery oft he Junkers Jumo 222 engines for installation in this aircraft. In the event, the Junkers power plants never arrived and, in consequence, the He 218B-3 never left the ground (Ref.: 8).

TYPE: Night and bad-weather fighter

ACCOMMODATION: Crew of two, pilot and navigator/radar-operator

POWER PLANT: Two Heinkel/Hirth HeS 011A turbojet engines, rates at 1.300 kp thrust each

PERFORMANCE: 540 mph at 19,685 ft

COMMENT: The Messerschmitt Me 262, nicknamed Schwalbe (German: “Swallow”) in fighter versions, or Sturmvogel (German: “Storm Bird”) in fighter-bomber versions, was the world’s first operational turbojet-powered fighter aircraft. Design work started before WW II began, but problems with engines, metallurgy and top-level interference kept the aircraft from operational status with the German Luftwaffe until mid-1944. The Me 262 was faster and more heavily armed than any Allied fighter, including the British turbojet-powered Gloster Meteor. One of the most advanced aviation designs in operational use during World War II, the Me 262’s roles included light bomber, reconnaissance and experimenat night fighter versions.
While the Messerschmitt Me 262 was not a difficult aircraft to fly, it possessed its share of idiosyncrasies, and some problems arose in the conversion of inexperienced pilots who had just completed their fighter training on piston-engined types. So it was obvious that traing would be simplified by the availability of a dual-control two-seater, and, accordingly, Messerschmitt evolved a suitable conversion trainer, the Messerschmitt Me 262B-1a.
Only some 15 examples of this trainer were delivered as the importance  attached to the introduction of the Me 262 as a nocturnal interceptor resulted in additional trainers on the assemblxy line being converted  as night fighters under the designation Messerschmitt Me 262B-1a/U1.
Whereas the Me 2626B-1a/U1 was a hurried adaption of the training model, the Messerschmitt Me 262 with two more powerful Heinkel/Hirth HeS 011A turbojet engines was considered as the definitive night-fighting sub-type for service from mid-1945. Structurally, the principal change consisted of the insertion of additional fuselage section fore and aft the tandem cockpits, increasing overall length more than 3.5 ft. This provided the necessary space to restore the 900 ltr resp. 600 ltr fuel tanks.
The first aircraft possessed similar radar to that of the Me 262B-1a/U2, and flight trials should begin in March 1945. The drag of the „Hirschgeweih“ array, with its eight 7-mm-diameter dipoles, was such that it reduced maximum speed by 30 mph. Various attempts had been made to streamline the antennae, resulting in the „Morgenstern“ aerial system in which the short antennae protruded through the pointed nose cone, and it was calculated that this would restore 30 mph of the speed loss. In the event, it was decided to standardize on the centrimetric wavelength FuG 240 „Berlin“ radar with a disc scanner housed in a plastic radome above the nose-mounted cannon, this affording little or no drag. The second variant of this design was to be fitted with two Heinkel/Hirth HeS 011B turbojet engines of 1.500 kp thrust each, equipped with a „Berlin“ radar, and a crew of three in a pressurized cockpit.  The Me 262 night fighter variants retained the standard forward firing battery of four 30 mm MK 108 cannon, and, in addition, provision was made for two similar weapons in a „Schräge Musik“ arrangement immediately aft of the rear cockpit (Ref.: 7).

TYPE: Two-seat all weather and night interceptor

ACCOMMODATION: Pilot and radar operator

POWER PLANT: Two Daimler-Benz DB 603A-2, rated at 1,726 hp each

PERFORMANCE: 400 mph at 17,400 ft

COMMENT: The Dornier Do 335 “Pfeil” (“Arrow”) was a WW II heavy fighter built by the Dornier Company. The Do 335s performance was much better than other twin-engine designs due to its unique push-pull configuration and the lower aerodynamic drag of the in-line alignment of the two engines. It was Germany’s Luftwaffe fastest piston-engine aircraft of World War II. The Luftwaffe was desperate to get the design into operational use, but delays in engine deliveries meant that only a handful were delivered before the war ended.
In early 1944 the Do 335 was scheduled to begin mass construction, with the initial order of 120 preproduction aircraft to be manufactured by DWF (Dornier-Werke Friedrichshafen) to be completed no later than March 1946. This number included a number of bombers, destroyers (heavy fighters), and several yet to be developed variants. At the same time, DWM (Dornier-Werke München) was scheduled to build over 2000 Do 335s in various models, due for delivery in March 1946 as well.
While the Dornier Do 335A-0 assembly line at Oberpfaffenhofen was struggling to overcome delays in deliveries of power plants, airscrews, radio equipment and sub-contracted components and assemblies, a number of “Versuchs” (Test) machines for other “Pfeil” subtypes joined the test programme, these including the first two seat models, the Do 335A-6 bad-weather and night interceptor and the Do 335A-12 trainer..
The Dornier Do 335 V10 was the first prototype for the Do 335A-6 radar-equipped two set all weather and night interceptor in which a second cockpit for the radar operator was inserted aft and above the normal cockpit. In order to provide space for the additional cockpit the fuel tankage was drastically revised, the weapon bay being deleted and its space utilized for fuel, fuselage tankage being increased substantially. Cannon armament remained unchanged, but a FuG 101a radio altimeter was
introduced together with FuG 217J-2 “Neptun” intercept radar with wing-mounted antennae. Exhaust flame damping tubes for the fore and aft engines added their measure of drag to that provides by the second cockpit and the radar antennae, and normal loaded weight increased by app. 500 kg. Performance accordingly fell by 10 per cent, but whereas the Do 335 V10 had Daimler-Benz DB 603A-2 engines, the production Do 335 A-6 was intended to have DB 603E engines with provision for methanol-water injection (MW 50) for power boosting below the rated altitude of power plants. Provision was to be made in the wings for two MW 50 tanks, power being boosted to 2,400 hp at sea level per engine.
Production of the Dornier Do 335A-6 night and all-weather fighter had been transferred to the Heinkel factory at Vienna, but despite high priority allocated to the program, circumstances prevented the necessary jigs and tools being assembled (Ref: 7, 12).

TYPE: Night fighter

ACCOMMODATION: Crew of two, Pilot and Radar operator/navigator

POWER PLANT: Two Daimler-Benz DB 603G liquid-cooled engines, rated at 1,900 hp each

PERFORMANCE: 416 mph at 22,965 ft

COMMENT: The Heinkel He 219 “Uhu” (“Eagle Owl”) was a night fighter that served with the German Luftwaffe in the later stages of WW 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 Junkers Ju 88C and Messerschmitt 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 He 219 been available in quantity, it might have had a significant effect on the strategic night bombing offensive of the Royal Air Force; however, only 294 of all models were built by the end of the war and these saw only limited service.
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 Reichluftfahrtministerium (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 R. Lusser returned to Heinkel from Messerschmitt, he began work on a new high-speed bomber project called Heinkel He 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 (quickly orienting the nose wheel into the required horizontal position for stowage within the nose, only at the very end of the retraction cycle) to fit flat within the forward fuselage and remotely controlled, side mounted FDSL 131 defensive gun turrets similar to those used by the Messerschmitt Me 210. Power was to be provided by two of the potentially troublesome, dual-crankcase Daimler-Benz DB 610 “power system” engines then under development, weighing on the order of about 1–​¹⁄₂ tonnes apiece, producing 2,950 hp each, delivering excellent performance with a top speed of approximately 470 mph and a 2,500 mi range with a 2,000 kg 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 Heinkel He P.1056, a night fighter with four 20 mm cannon 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 Heinkel He P.1060. This design was similar in layout but somewhat smaller and powered by two of the largest displacement  single-block liquid-cooled aviation engines placed in mass production in Germany, the Daimler-Benz DB 603 inverted V12 engine. As designed by Heinkel, these engines’ nacelle accommodations featured annular radiators similar to the ones on the Junkers Jumo 211-powered Junkers Ju 88A, but considerably more streamlined in appearance, and which, after later refinement to their design, were likely to have been unitized as a Heinkel-specific “Kraftei” (Power egg) engine unit-packaging design. Nearly identical-appearance nacelles, complete with matching annular radiators, were also used on the four prototypes Heinkel He 177B prototype airframes built in 1943-44, and the six ordered prototypes of Heinkel’s He 274 high-altitude strategic bombers with added turbochargers. The early DB 603 subtypes had poor altitude performance, which was a problem for Heinkel’s short-winged design, but Daimler had a new “G” subtype of the DB 603 power plant meant to produce 1,900 hp take-off power apiece 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 Junkers Ju 88- and Messerschmitt 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 Focke-Wulf Fw 190C high-altitude fighter prototypes were already starting to use into early 1943, with the DB 603. DB 603 engines did not arrive until August 1942 and the prototype did not fly until November 1942.
When Kammhuber saw the prototype, he was so impressed that he immediately ordered it into production over Milch’s objections. Milch – who had rejected the He 219 in January in favor of the Junkers Ju 388J 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 complement of the aircraft was increased to two Mauser MG 151/20 20 mm cannon in the wing roots, inboard of the propeller arcs to avoid the need for gun synchronizers, with four more MG 151/20 cannon mounted in the ventral fuselage 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 Heinkel He 219A-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 Heinkel He 219A-0 and quickly progressed to the point where prototypes 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 blunt, compound-curvature metal nose cones also used for production-series He 219A airframes. The initial examples of these nose cones possessed cutouts for their use with the quartet of forward-projecting masts for the “Matratze” (“Mattress”) 32-dipole radar antennae on the noses of at least the first five prototypes, used with the early UHF-band “Lichtenstein” B/C or C-1 radar installation. 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. The fourth prototype, He 219 V4, equipped with the earlier canopy design, had a small degree of internal metal framing within 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 first major production series was the Heinkel He 219A-0, although initially the pre-production series, it matured into a long running production series, due to numerous changes incorporated into the design, along with the cancellation of several planned variants. Production problems as a result of Allied bombing in March meant the A-0 did not reach Luftwaffe units until October 1943. The A-0 was usually armed with two 20 mm MG 151/20 cannon in the wing roots and up to four 20 mm or 30 mm cannon in a ventral weapons bay. The first 10–15 aircraft were delivered with the 490 MHz UHF-band FuG 212 “Lichtenstein” C-1radar with a 4 × 8-dipole element “Matratze” antenna array. 104 Heinkel He 219A-0s were built until the summer of 1944, the majority of them at EHW (Ernst Heinkel Wien) or Heinkel-Süd in Wien-Schwechat (Ref.: 24).