TYPE: Fighter project, forerunner of the Heinkel He 162
ACCOMMODATION: pilot only
POWER PLANT: one Heinkel-Hirth HeS 011 turbojet engine, rated at 1.300 kp thrust
PERFORMANCE: 615 mph in 19615 ft
COMMENT: The summer 1944 saw limitations of the Messerschmitt Me 262 becoming readily apparent. The basic design predated the war. It was heavy and expensive, and required to precious turbojet engines. A cheap high-performance replacement was needed so in July 1944 the RLM issued a requirement for a new single-turbojet high-performance fighter, known as the “1-TL-Jäger”. Germany’s aircraft companies were quick to realise that this was potentially the most important competition in which they had so far had the opportunity to participate. Designing a successful single-seat fighter carries a huge amount of prestige and the most famous firms – Blohm &Voss, Focke-Wulf , Heinkel, Junkers and Messerschmitt – jumped at the chance to create the successor to not only on the me 262 but perhaps also the Bf 109 and Fw 190 too. The engine was to be a Heinkel-Hirth HeS 011 turbojet and the companies were allowed two months to prepare their first designs, Blohm & Voss had two months more time.
On September 1944 the designs were presented at a meeting at Messerschmitt’s Oberammergau facility. It is not known which designed were presented by Messerschmitt and Heinkel, though it is likely that these were one of the earliest versions of the former’s Me P.1101, and the latter’s He P.1073 or a variant of it. Focke-Wulf put forward a twin-boom design Nr.280 it had been working on since early 1944. Blohm & Voss’s design (P.212) was apparently not ready and furthermore it was agreed that Junkers should also be allowed to submit a tender for the requirement.
On the last day of the meeting, a new requirement was suddenly and for most part unexpectedly issued for what would become the “Volksjäger” (Peoples Fighter). This called for a fighter powered by a single BMW 003 turbojet engine that could reach a maximum speed of 466 mph and have an endurance of 30 minutes at full throttle. It also had to be able to operate from poor airfields.
This urgent demand for new single-turbojet fighter designs that could be built in a hurry from low grade non-strategic materials effectively stalled work on the “1-TL-Jäger” competition for several months, particularly Blohm & Voss, Focke-Wulf, Heinkel and Junkers all hastily drafted entries for the “Volksjäger” contest.
The Heinkel He P.1073, originally designed before July 1944 as a fighter with two Junkers Jumo 004C turbojet-engines, one under the nose and one at its back but now altered to fly with just one Heinkel-Hirth HeS 011, was already close to meeting the “Volksjäger” specification. The Heinkel “Volksjäger”-design He P.1073.01.18 was dated from September 1944, just one day after the specification was issued. This only was possible because Heinkel’s design team had several different variants of the design on the drawing board. The documentation describes the He P.1073.01.18 as a “Kleinst-Jäger” (Midget Fighter) and states it is ”a simplification of the design with HeS 011”. It bears remarkable resemblance to what would become the Heinkel He 162 “Spatz” (Sparrow”) except the wings are simpler and both nose wheel and main gear retract forward into the fuselage. Heinkel’s design received a similarly lukewarm reaction, probably because it was based heavily on the company’s already known “1-TL-Jäger” project. But Heinkel’s representatives pointed out that with aircraft such as the Heinkel He 177 bomber no longer in production there was now spare capacity available at its capacious and well-equipped factories. There is some evidence that on September 23rd 1944 Hitler himself ordered the He P.1073 into mass production as Heinkel He 162.
The variant of the He P.1073 design that finally led to the definitive Heinkel He 162 “Volksjäger” is shown here. The design is dated back from September 10th, 1944 and shows the installation of the turbojet engine on the back. The wings are swept back at 35 degree, the tail plane had a positive dihedral and two fins. Under the fuselage on ventral starboard side a streamlined pannier was fitted holding a MK 108 machine canon and two MG 213C machine guns were oblique mounted in the front at both sides of the pilot’s seat. Work on the final version of the Heinkel “Volksjäger began on October 25th, 1944 and its maiden flight took place on December 6th that year (Ref.: Sharp, Dan: Luftwaffe. Secrets Jets of the Third Reich. Mortons Media Group Ltd, Horncastle, 2015).
POWER PLANT: Two Junkers Jumo 004C, rated at 1050 kp each or two Heinkel/Hirth HeS 011 turbojet engines, rated at 1,200 kp each
PERFORMANCE: High sub-sonic speed (estimated)
COMMENT: The Messerschmitt Me 262 HG IV („Hochgeschwindigkeits-Projekt IV“, „High-speed Project IV“) was a high-speed concept which would be based on the Messerschmitt Me 262 „Schwalbe“ („Swallow“). The design dates back to early 1940 when attempt were made to test the revolutionary turbojet driven aircraft at critical Mach numbers.
Several proposals were calculated on the drawing board and even one design realized:
The Messerschmitt Me 262 V9 HG I was flight tested in January 1944. During the course various aerodynamic improvements were introduced into a basic Me 262 aircraft. The leading edge of the inner wing as well as of the vertical tail was increased to 45 degree, the leading edge of the horizontal tail was swept back to 40 degree, a shallow, low-drag cockpit canopy was installed, and the muzzles were faired over. The highest speed attained by this experimental aircraft being 624 mph.
On the drawing board remained the Messerschmitt Me 262 HG II and Me 262 HG III, both designs in various subtypes with different wings, conventional as well as with “Butterfly”-type tail plane, different engine installation and air intake.
Finally, the Messerschmitt Me 262 HG IV was a basic Messerschmitt Me 262 aircraft with original wing section and low mounted nacelles, housing the turbojet engines, but an intensively modified fuselage similar to the Me 262 HG III/3. The cockpit was placed to the rear of the fuselage merging into the tail plane, fuel tanks and armament was set at the front of the aircraft.
All Messerschmitt Me 262 HG II, Me 262 HG III and Me 262 HGIV were never realized
POWER PLANT: Two Daimler-Benz DB 603A-2, rated at 1,726 hp each
PERFORMANCE: 430 mph at 17,400 ft
COMMENT: The Dornier Do 335 “Pfeil” (“Arrow”) was a WW II heavy fighter built by the Dornier company. The two-seater trainer version was unofficially called “Ameisenbär (“Anteater”). 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.
The Dornier Do 335 V1 first prototype flew for the first time on October 1943. However, several problems during the initial flight of the Do 335 would continue to plague the aircraft through most of its short history. Issues were found with the weak landing gear and with the main gear’s wheel well doors, resulting in them being removed for the remainder of the V1’s test flights. The Do 335 V1 made 27 flights, flown by three different pilots. During these test flights the second prototype Do 335 V2 was completed and made its first flight on end December 1943. New to the V2 were upgraded DB 603A-2 engines, and several refinements learned from the test flights of the V1 as well as further wind tunnel testing.
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.
The first preproduction Dornier Do 335A-0s were delivered in July 1944 to the “Erprobungskommando 335” (“Proving detachment 335”) formed for service evaluation purposes.
On May 1944, Hitler, as part of the developing “Jägernotprogramm” (Emergency Fighter Program) directive, which took effect on July that year, ordered maximum priority to be given to Do 335 production. The main production line was intended to be at Manzell, but bombing raids in March destroyed the tooling and forced Dornier to set up a new line at Oberpfaffenhofen.
Among the different variants of the Do 335 under construction were two further two-seat prototypes, the Do 335 V11 and V12, these being respectively prototypes for the Daimler-Benz DB 603A-2-powered Do 335A-10 and DB 603E-1-powered Do 335A-12 dual-control conversion trainer. Having a similar raised second cockpit inserted aft and above the normal cockpit, the Do 335A-10 was equipped with full instrumentation and controls and was occupied by the instructor. The first aircraft were delivered without armament, but similar armament to that of the Do 335A-1 was specified for production models which were interspersed on the Do 335A-1 assembly line, and the genuine production aircraft was, in fact, a Do 335A-12 trainer.
At least 16 prototype Do 335s were known to have flown (V1–V12, and Muster-series prototypes M13–M17) on a number of DB603 engine subtypes including the DB 603A, A-2, G-0, E and E-1. The first preproduction Do 335A-0s were delivered in July 1944. Approximately 22 preproduction aircraft were thought to have been completed and flown before the end of the war including approximately 11 A-0s converted to A-11s for training purposes.
When U.S. forces overran Dornier’s Oberpfaffenhofen factory only 11 Do 335A-1 single-seat fighter bombers and two Do 335A-12 conversion trainers had been completed, but a further nine A-1s, four A-4s and two A-12s were in final assembly, and components and assemblies for nearly 70 additional aircraft had been completed. Production of the 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).
POWER PLANT: One Daimler-Benz DB 601 ARJ liquid-cooled engine, rated at 1,775 hp
PERFORMANCE: 469 mph
COMMENT: The Messerschmitt Me 209 V1 was a single-engine racing aircraft which was designed for and succeeded at breaking speed records.
The designation Me 209 was used for two separate projects during World War II. The first was a record-setting, single-engined race aircraft, for which little or no consideration was given to adaptation for combat. The second Me 209 V4 was a proposal for a follow-up to the highly successful Messerschmitt Bf 109 which served as the Luftwaffe’s primary fighter throughout World War II.
Designed in 1937, the Me 209 V1 was a completely separate aircraft from the Messerschmitt Bf 109, solely designed to break speed records. It shared only its Daimler-Benz DB 601 engine with the Bf 109, which in the Me 209 was equipped with steam cooling. Willy Messerschmitt designed the small aircraft with a cockpit placed far back along the fuselage just in front of its unique cross-shaped tail section. Unlike the Bf 109, the Me 209 featured a wide track, inwardly-retracting undercarriage mounted in the wing section.
The aircraft achieved its purpose when test pilot Fritz Wendel flew it to a new world speed record of almost 469 mph on 26 April 1939, bearing the German civil registration D-INJR. This record was not officially broken by another piston-engined aircraft until 16 August 1969 by Darry Greenamyer’s highly modified Conquest F8F “Bearcat”.
The Me 209 V1’s speed record was itself shattered in terms of absolute speed, eighteen months later by Heini Dittmar, flying another Messerschmitt aircraft design, the Messerschmitt Me 163A V4 rocket fighter prototype to a 624 mph record in October 1941.
The idea of adapting the Messerschmitt Me 209 racer to the fighter role gained momentum when, during the Battle of Britain, the Messerschmitt Bf (Me)109 failed to gain superiority over the Royal Air Force’s Supermarine “Spitfire”. The little record-setter, however, was not up to the task of air combat. Its wings were almost completely occupied by the engine’s liquid cooling system and therefore prohibited conventional installation of armament. The aircraft also proved difficult to fly and extremely hard to control on the ground. Nevertheless, the Messerschmitt team made several attempts to improve the aircraft’s performance by giving it longer wings, a taller vertical stabilizer, and installing two synchronized 7.92 mm MG 17 in the engine cowling. Several modifications on the aircraft, designated Messerschmitt Me 209 V4, however, added so much weight that the aircraft ended up slower than the contemporary Bf 109E. As a result the complete Messerschmitt Me 209 project was soon cancelled, but was revived later in form of the Messerschmitt Me 209 V5. (Ref.: 24).
POWER PLANT: Three BMW Bramo 323 R-2 Fafnir radial engine, rated at 1,184 hp with MW-50 each
PERFORMANCE: 230 mph at 16,565 ft
COMMENT: The Junkers Ju 352 “Herkules” (“Hercules”) was a German WW II transport aircraft that was developed from the Junkers Ju 252.
During the late spring of 1942, the Junkers-Dessau project office was instructed by the Reichsluftfahrtministerium (RLM, Reich Air Ministry) to investigate the possibility of redesigning the structure of the Junkers Ju 252 transport to make maximum use of non-strategic materials, simultaneously replacing the Junkers Jumo 211F engines of the Ju 252 (production of which could barely keep pace with the demands of combat aircraft) with BMW Bramo 323R radial engines. The result followed closely the aerodynamic design of the Ju 252 but was an entirely new aircraft. The wing of the Ju 352 was similar in outline to that of the Ju 252 but, mounted further aft on the fuselage, was entirely of wooden construction.
The Ju 352 also had a similar hydraulically-operated “Trapoklappe” (“Transportklappe”, rear loading ramp) to that of the Ju 252. The ramp allowed the loading of vehicles or freight into the cargo hold while holding the fuselage level. Theoretically it was possible for any wheeled vehicle up to the size of a large “Kübelwagen” to drive up the Trapoklappe into the freight hold, although in practice it proved necessary to winch the vehicle into the hold by means of a manually-operated block- and tackle arrangement owing to the risk of damaging the structure.
In general, the Ju 352 was considered a major improvement over the original Junkers Ju 52 but noticeably inferior to the Junkers Ju 252. Deliveries of the Ju 352 had only just begun to get into their stride when, during the summer of 1944, the worsening war situation resulted in the decision to abandon further production of transport aircraft. In September the last two Ju 352As rolled off the assembly line, 10 pre-production Ju 352s and 33 production Ju 352s having been manufactured. Several developments of the basic design were proposed before production was halted, these including the Ju 352B with more powerful engines and increased defensive armament (Ref.: 24).
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 HeinkelWien) or Heinkel-Süd in Wien-Schwechat (Ref.: 24).
COMMENT: The DFS 346 was a German rocket-powered swept-wing aircraft subsequently completed and flown in the Soviet Union after WW II. It was designed by Felix Kracht at the Deutsche Forschungsanstalt für Segelflug (DFS, “German Research Institute for Sailplanes”). The prototype was still unfinished by the end of the war and was taken to the Soviet Union where it was rebuilt, tested and flown.
The DFS-346 was a midwing design of all-metal construction. The front fuselage of the DFS 346 was a body of rotation based on the NACA-Profile 0012-0,66-50. The middle part was approximately cylindrical and narrowed to the cut off to accommodate vertically arrayed nozzles in back. Probably for volume and weight reasons the DFS-346 was equipped with landing skids, both in the original German design and in the later Soviet prototypes; this caused trouble several times.
The wings had a 45° swept NACA 0012-0,55-1,25 profile of 12% thickness. The continuously varying profile shape caused a stall in certain flight conditions, which caused complete loss of control. This was later corrected by use of fences on the top of the wings.
The DFS 346 was a parallel project to the DFS 228 high-altitude reconnaissance aircraft, designed under the direction of Felix Kracht and his team at DFS. While the DFS 228 was essentially of conventional sailplane design, the DFS 346 had highly-swept wings and a highly streamlined fuselage that its designers hoped would enable it to break the sound barrier.
Like its stablemate, it also featured a self-contained escape module for the pilot, a feature originally designed for the DFS 54 prior to the war. The pilot was to fly the machine from a prone position, a feature decided from experience with the first DFS 228 prototype. This was mainly because of the smaller cross-sectional area and easier sealing of the pressurized cabin, but it was also known to help with g-force handling.
The DFS 346 design was intended to be air-launched from the back of a large mother ship aircraft for air launch, the carrier aircraft being the Dornier Do 217K as with the DFS 228. After launch, the pilot would fire the Walter HWK 109-509B/C twin-chamber engine to accelerate to a proposed speed of Mach 2.6 and altitude of 100,000 ft. This engine had two chambers — the main combustion chamber as used on the earlier HWK 509A motor; but capable of just over two short 2,000 kp of thrust at full power, and the lower-thrust “Marschofen”, (Cruise chamber = throttleable chamber of either 300 kp (B-version) or 400 kp (C-version) top thrust levels mounted beneath the main chamber. After reaching altitude, the speed could be maintained by short bursts of the lower “Marschofen” (cruise chamber).
In an operational use the plane would then glide over England for a photo-reconnaissance run, descending as it flew but still at a high speed. After the run was complete the engine would be briefly turned on again, to raise the altitude for a long low-speed glide back to a base in Germany or northern France.
Since the aircraft was to be of all-metal construction, the DFS lacked the facilities to build it and construction of the prototype was assigned to Siebel Werke located in Halle, where the first wind tunnel models and partially built prototype were captured by the advancing Red Army.
On 22 October 1946, the Soviet OKB-2 (Design Bureau 2), under the direction of Hans Rössing and Alexandr Bereznyak, was tasked with continuing its development. The captured DFS 346, now simply called “Samolyot 346” (“Samolyot” = Aircraft) to distance it from its German origins, was completed and tested in TsAGI wind tunnel T-101. Tests revealed some aerodynamic deficiencies which would result in unrecoverable stalls at certain angles of attack. This phenomenon involved a loss of longitudinal stability of the airframe. After the wind tunnel tests, two wing fences were installed on a more advanced, longer version of the DFS-346, the purpose of fences was to interrupt the spanwise movement of airflow that would otherwise bring the boundary-layer breakdown and transition from attached to stalled airflow with loss of lift and increase of drag.
This solution was used on the majority of the Soviet planes with sweptback wings of the 1950s and 1960s. In the meantime, the escape capsule system was tested from a North American B-25J “Mitchel” piston engine medium bomber and proved promising. Despite results from studies showing that the plane would not have been able to pass even Mach 1, it was ordered to proceed with construction and further testing.
In 1947, an entirely new 346 prototype was constructed, incorporating refinements suggested by the tests. This was designated “346-P” (“P” for planer = “glider”). No provision was made for a power plant, but ballast was added to simulate the weight of an engine and fuel. This was carried to altitude by a Boeing B-29 “Superfortress” captured in Vladivostok and successfully flown by Wolfgang Ziese in a series of tests. This led to the construction of three more prototypes, intended to lead to powered flight of the type.
Newly built “346-1“ incorporated minor aerodynamic refinements over the 346-P, and was first flown by Ziese on September 30, 1948, with dummy engines installed. The glider was released at an altitude of 9700 m, and the pilot realized that he hardly could maintain control of the aircraft. Consequently, while attempting to land, he descended too fast (his speed was later estimated at 310 km/h). After first touching the ground he bounced up to a height of 3–4 m and flew 700–800 m. At the second descent, the landing ski collapsed and the fuselage hit the ground hard.
The pilot seat structure and safety belt proved to be very unreliable, because at the end of a rough braking course Ziese was thrown forward and struck the canopy with his head, losing consciousness. Luckily, he wasn’t seriously injured, and after treatment in hospital he was able to return to flying. Accident investigation research team came to the conclusion that the crash was a result of pilot error, who failed to fully release the landing skid. This accident showed that the aircraft handling was still very unpredictable, as a result, all rocket-powered flights were postponed until pilots were able to effectively control the aircraft in unpowered descent, requiring further glide flights.
The damaged 346-1 was later repaired and modified to 346-2 version. It was successfully flown by test pilot P.Kazmin in 1950-1951 winter, but nonetheless these flights also ended “on fuselage”. Furthermore, after the last flight of these series, the airframe again required major repairs. On 10 May 1951, Ziese returned to the program, flying final unpowered test flights with the 346-2, and from 6 June, unpowered tests of the 346-3 without accidents.
By the mid-1951 346-3 was completed, and Ziese flew it under power for the first time on 13 August 1951, using only one of the engines. Continuing concerns about the aircraft’s stability at high speeds had led to a speed limit of Mach 0.9 being placed during test flights. Ziese flew it again on 2 September and 14 September. On this last flight, however, things went drastically wrong. Separating from the carrier plane at 9,300 meters (30,500 ft) above Lukovici airfield, the pilot fired the engine and accelerated to a speed of 900 km/h (560 mph). The rocket engine worked as expected, and 346-3, quickly accelerating, started ascending and soon had flown in very close proximity of its carrier aircraft. Ziese then reported that the plane was not responding to the controls, and was losing altitude. Ground control commanded him to bail out. He used the escape capsule to leave the stricken aircraft at 6,500 meters (21,000 ft) and landed safely by parachute. With the loss of this aircraft, the 346 program was abandoned (Ref.:24).
POWER PLANT: One Walter HWK 109-509A-2 liquid-fuel rocket engine rated between 1,500 kp to 100 kp full variable
PERFORMANCE: 559 mph at all altitudes
COMMENT: The Messerschmitt Me 163 “Komet” (“Comet”) was a German rocket-powered interceptor aircraft. Designed by A. Lippisch, it was the only rocket-powered fighter aircraft ever to have been operational and the first piloted aircraft of any type to exceed 1000 km/h (621 mph) in level flight. Its performance and aspects of its design were unprecedented. The Messerschmitt Me 163 “Komet” was among the most technically advanced and inherently dangerous military aircraft ever to see service. The radical ‘tailless’ design was developed by Dr Alexander Lippisch as the DFS 194 at the Deutsche Forschungsanstalt für Segelflug, (German Research Institute for Sailplanes) at Darmstadt in the 1930s. In January 1939, project work on the DFS 194 was transferred to Messerschmitt AG at Augsburg responsible for fitting a rocket motor. Lippisch also moved to Messerschmitt AG to head the development project team. The rocket-powered sailplane DFS 194 made its first flight on August 1940 what was very successful. Although Messerschmitt was not impressed by the concept of a rocket-powered interceptor, Lippisch and his team continued work on the project. Officially designated Messerschmitt Me 163 the aircraft was first flown under rocket power in 1940 becoming the first aircraft to exceed 1000 km/h, experiencing control problems on the edge of the sound barrier.
Five prototype Messerschmitt Me 163A V-series aircraft were built, adding to the original DFS 194 (V1), followed by eight pre-production examples designated as Me 163 A-0. These aircraft were intensively tested by the Luftwaffe and although its extraordinary acceleration, climbing characteristics and speed inspired the authorities the handling of this tiny aircraft especially during take-off and landing showed tremendous problems. The rocket engine gave power for only a few minutes and the rest of the flight had to be continued as a glider.
Five prototypes and eight pre-production examples were followed by 30 completely redesigned production aircraft Messerschmitt Me 163B-0. These aircraft were armed with two 20 mm MG 151/20 cannon and some of these were allocated to “Erprobungskommando16” (EKdo 16) (“Testing-command 16”) that was formed March 1943 in Peenemünde-West, as a test unit for the rocket fighter, and later based at the Luftwaffe airfield in Bad Zwischenahn for a considerable period of time. This EKdo 16 had some of the aircraft painted completely in red and was the first Luftwaffe unit to perform a combat mission.
The performance of the Me 163 far exceeded that of contemporary piston engine fighters. At a speed of over 200 mph the aircraft would take off, in a so-called “Scharfer Start” (“sharp start”, “sharp take-off”) from the ground, from its two-wheeled dolly. The aircraft would be kept at level flight at low altitude until the best climbing speed of around 420 mph was reached, at which point it would jettison the dolly, retract its extendable landing skid and then pull up into a 70° angle of climb, to a bomber’s altitude. It could go higher if required, reaching 39,000 ft in an unheard-of three minutes. Once there, it would level off and quickly accelerate to around 550 mph or faster, which no Allied fighter could match. Flight endurance under power was just eight minutes after which the aircraft became a glider, and the time available to attack enemy aircraft using two 20mm cannons was very limited. Once the rocket’s fuel supply was exhausted the Me 163B “Komet” was an easy target for fighter aircraft, particularly during the landing phase (Ref.: 24).
ACCOMMODATION: Pilot only in prone position in pressurized cockpit
POWER PLANT: One Walter HWK 109-509 bi-fuel liquid rocket engine, rated at 1,650 kp at 40,000 ft
PERFORMANCE: 435 mph at 75,459 ft
COMMENT: Beginning in 1940, the DFS (Deutsches Forschungsinstitut für Segelflug, German Research Institute for Sailplanes) started an ambitious program to achieve supersonic flight. Since the only engines powerful enough and available at the time were rocket engines, it was realized that the solution was to have the assault on the sound barrier take place at a high altitude. It was decided to divide the program into three sections:
The first part was concerned with developing and testing of the pressurized cockpit section, the method of pilot escape in case of emergency and performance testing of rocket engines at high altitudes.
The second part was to discover the performance of various sweptback wing configurations. The DFS acquired the Heinkel P.1068 designs for a four-engined turbojet bomber with various wing sweep angles.
The third and last part was to actually build a supersonic aircraft with information learned in the above two steps, which was eventually to become the DFS 346.
The DFS decided to design a new aircraft (although much was learned in an earlier design, the DFS 54) to investigate the first part of their three-step program. Thus, in 1941, the RLM assigned the number 228 to the aircraft, and requested that the DFS 228 also be designed for high-altitude reconnaissance duties as well as research work.
The first prototype of the DFS 228 (coded D-IBFQ) was completed in 1943 by the DFS, although the control sections and landing skid were built by Schmetz Company. The fuselage of the DFS 228 V1 consisted of three circular sections: the nose section containing the cockpit; a center section which contained the landing skid, fuel tanks and a Zeiss infra-red camera; and the tail section with the Walter HWK 509A-1 or A-2 rocket engine. The wing was attached at the mid-fuselage point, and featured 4.5 degrees of dihedral. Wooden construction was used for the entire wing, with a single laminated wooden spar running from wingtip to wingtip, wooden ribs and a plywood covering. Wide-span divided ailerons were fitted to the wing (the inner section acted as landing flaps), and lift spoilers were also fitted to the upper and lower wings. A conventional tail unit was used, also with all wooden construction. Landing was done on a retractable skid. Since the DFS 228 was to operate in extremely high altitudes, a completely pressurized cockpit was designed. Although it was thought at first that the pressure cabin could be of wooden construction, a metal compartment was built after the wooden one failed to hold sufficient pressure. The nose section was double-walled constructed with aluminum foil insulation. The V1 prototype had a conventional seated pilot’s position, but the V2 and later aircraft were to have a prone pilot position, due to the difficulty of of sealing such a large compartment with the pilot seated upright. All glazed areas were made of double layered Plexiglas and were provided with warm air circulation between layers to prevent frosting of the Plexiglas.
After pressure sealing problems became apparent on the V1 cockpit, it was decided to go with a prone pilot. An adjustable horizontal couch was provided for the pilot to lay on; all controls, oxygen supplies and cockpit equipment mounted directly to the steel tube structure which was then attached directly to the main fuselage bulkhead at the back of the cockpit. This also had the added advantage of keeping the pressurized area small. Thus it was easier to keep sealed. The new cockpit arrangement was incorporated in to the DFS 228 V2 and later aircraft.
A very interesting flight plan was arranged for the operational recognizance DFS 228. It was to be mounted above (or could be towed behind) a carrier aircraft (usually a Do 217K), where it was then carried to approximately 32.808 feet. Upon release, the DFS 228 would then ignite its rocket engine until an altitude of about 75.460-82.021 feet was reached. By this time, the DFS 228 would be over its photographic target area and after its reconnaissance mission was fulfilled, the aircraft would then make a long glide back to base.
In the case of an emergency at high altitudes, the complete pressurized nose section (with all life support equipment attached) could be jettisoned by firing four explosive bolts, or it could take place automatically when the cockpit pressure dropped below a minimum level. An automatic parachute would then deploy to stabilize and slow the descent. When a safe altitude was reached, the pilot was ejected by compressed air, and would then descend to the ground using his personal parachute. This escape procedure was successfully tested by the Soviets after the war, with a captured DFS 346, which had a similar escape system.
DFS 228 V1 flight trials were made at Hörsching, southwest of Linz, by the DFS and also by Erprobungsstelle Rechlin in late 1944. Over 40 test flights were made, and although powered flight was to take place in February 1945, none were actually made using rocket power, and none exceeded 32.808 feet. It was in these tests that the upright pilot’s position was found to be unsuitable for proper cockpit pressurization. The decision was made to go with the prone position cockpit, and was included into the DFS 228 V2, which was built and also flight tested.
The main faults found with the 228 were that it suffered from poor aileron effectiveness at high altitudes and that the elevators were very sensitive. Other than the early pressurization problems, the general handling was satisfactory and the problems would not hamper the intended role of the aircraft. A potential problem could have arisen with the use of the Walter HWK 509A1 or A-2 rocket engines, due to the fact that the flight profile meant for the rocket engine to be intermittently operated, and the possibility existed of valves and pumps freezing up at the extreme altitudes and low temperatures in which the flight was to take place. Of course, newer rocket engines were continually being developed, and perhaps some sort of heating system or the possibility of using M-Stoff and A-Stoff (methanol and oxygen) for fuels, which could have operated at much lower temperatures, could have been developed.
Although powered flight had not been attempted at the time of Germany’s collapse, the construction of a pre-production batch of 10 DFS 228A-0 aircraft had begun at Griesheim, near Darmstadt.
The DFS 228 V2 was destroyed at Hörsching in May 1945, only the forward section had parts worth salvaging. The DFS 228 V1 survived the war, and was surrendered at Ainring in the US Zone of Occupation. On June 18, 1945, it was taken by road to the US Air Technical Intelligence Unit at Stuttgart. It was later sent to the RAE Farnborough in June 1946, and although allegedly was sent to the scrap pile in 1947, another report has the DFS 229 V1 being sent to Slingsby Sailplanes Ltd. at Kirkbymoorside in Yorkshire. Strangely enough, Slingsby offered a design for their T44, a stratospheric research sailplane which incorporated several DFS 228 features, including the detachable pressurized cockpit section (Ref.: 17).
POWER PLANT: One Argus As 10c air-cooled inline piston engine, rated at 240 hp
PERFORMANCE: 103 mph
COMMENT: German helicopter development began with Focke-Wulf’s acquisition of the rights to manufacture Cierva autogyros during the 1920’s. Over 30 Cierva C.19 and C.30 autogyros were built during the late 1920’s and early 1930’s, and from this experience, Heinrich Focke, the engineering half of the Focke-Wulf company, decided to develop an original autogyro design to compete in the Luftwaffe’s contest to provide a utility-liaison aircraft. The Focke-Wulf entry, designated Fw 186, was essentially a Focke-Wulf Fw 56 “Stösser” (Goshawk) parasol wing advanced trainer, with wings removed, tail unit and landing gear redesigned, and configured for two seats in tandem. The engine remained unchanged, with a clutch arrangement installed to start the blades rotating for takeoff. An autogyro, similar in principle to today’s gyrocopters, uses the main power plant for forward thrust, while the rotors freewheel in flight. The aircraft could take off and land in very short distances, but it could not hover or take off and land vertically.
The first flight of the Focke-Wulf Fw 186 was on July 1939 and although very successful, it was beaten out by the Fieseler Fi 156 “Storch” (Stork) for the Luftwaffe contract, and disappeared from the scene afterward. Only two examples were built (Ref.: Planet Models).
Scale 1:72 aircraft models of World War II
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