TYPE: Trainer aircraft

ACCOMMODATION: Pilot and Instructor

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).

TYPE:  Scaled-down research aircraft

ACCOMMODATION: Pilot only

POWER PLANT: One Hirth HM 60 four cylinder inverted air-cooled in-line piston engine, rated at 80 hp, driving a four-bladed pusher propeller via an extension shaft

PERFORMANCE: 137 mph

COMMENT: The Göppingen Gö 9 was a research aircraft built to investigate the practicalities of powering a plane using a pusher propeller located far from the engine and turned by a long driveshaft. In 1937, Claudius Dornier observed that adding extra engines and propellers to an aircraft in an attempt to increase speed would also attract a penalty of greater drag, especially when placing two or more engines within nacelles mounted on the wings. He reasoned that this penalty could be minimized by mounting a second propeller at the rear of an aircraft. In order to prevent tail-heaviness, however, the engine would need to be mounted far ahead of it. Dornier patented this idea and commissioned a test plane to evaluate it. This aircraft was designed by Dr. Hütter as a 40% sized, scaled-down version of the Dornier Do 17 ‘Fast bomber’ fuselage and wing panels without the twin-engine nacelles, and built by Schempp-Hirth at Wüsterberg. The airframe was entirely of wood and used a retractable tricycle landing gear – one of the earliest German airframe designs to use such an arrangement. Power was supplied by a Hirth HM 60 inverted, air-cooled inline four-cylinder engine mounted within the fuselage near the wings. Other than the engine installation, the only other unusual feature of the aircraft was its all-new, full four-surface cruciform tail, which included a large ventral fin/rudder unit of equal area to the dorsal surface. This fin incorporated a small supplementary tail-wheel protruding from the ventral fin’s lower tip that assisted in keeping the rear-mounted, four-blade propeller away from the ground during take-off and landing. The Gö 9 carried the civil registration D-EBYW. Initially towed aloft by a Dornier Do 17, flight tests began in June 1941, but later flights operated under its own power. The design validated Dornier’s ideas, and he went ahead with his original plan to build a high-performance aircraft with propellers at the front and rear, producing the Dornier Do 335 ‘Pfeil’ (‘Arrow’) the fastest fighter aircraft in service during WW II. The eventual fate of the Gö 9 is not known (Ref.: 24)

TYPE: Trainer

ACCOMMODATION: Crew of two

POWER PLANT: Two Argus As 10 C air-cooled engines, rated at 250 hp each

PERFORMANCE: 212 mph

COMMENT: To support the development of flying wing aircraft the Luftwaffe founded a special “Luftwaffen-Sonderkommando 9” (Air Force Special Command 9). This command ordered several two-seater flying wing trainers for pilots who should fly the on-coming Horten/Gotha Go 229 twin-engine flying wing turbojet fighter. In 1943, based on the Horten V the Horten Brothers developed the Horten Ho VII, a flying wing with an enlarged center section to hold a longer canopy for a crew of 2, and greater fuel tanks. The wing sections remained nearly unchanged. Two aircraft were built by Peschke Company at Minden and flight tested at Minderheide airfield, the Ho VII V-1 with fixed undercarriage, the Ho VII V-2 with retracting undercarriage, the front wheel backwards and the main wheels forwards into the fuselage. Further tests were performed by Skoda-Kauba-Flugzeugwerke at Ruzyn airfield close to Prague (occupied by Germany at that time). In 1945 an order calling for 20 Ho VII trainers was placed as trainer for the Horten/Gotha Go 229 flying wing turbojet fighter. With the end of WW II all work was cancelled (Ref.: 19).

TYPE: Experimental flying wing

ACCOMMODATION: Pilot only

POWER PLANT: Two Hirth HM 60R inline engines, rated at 80 hp each, driving pusher propellers

PERFORMANCE: 218 mph

COMMENT: Walter and Reimar Horten, credited as the Horten Brothers, were German aircraft pilots and enthusiasts. Although they had little, if any, formal training in aeronautics or related fields, the Horten Brothers designed not only some outstanding gliders but some of the most advanced aircraft of the mid 1940s, including the world’s first jet-powered flying wing, the Horten Ho 229. Early in 1930, both began their career by designing some outstanding gliders, most of them in flying wing configuration. The first Horten Ho I glider was awarded for its excellent construction and was followed by the Horten Ho II that, after flight testing as glider, was powered  by one Hirth HM 60 R engine with pusher-type propeller. Further development was the Horten Ho III, a high performance glider, of which 14 aircraft were built, and the Horten Ho IV, also a high performance glider. In 1936, supported by the Dynamit Noble Company, construction of the Horten Ho V began, a twin engine flying wing with two seats and built completely from “Trolitax”, a new synthetic material. Most advanced was its control system by combining lateral and yaw control. Undamped vibrations occurred during flight and the aircraft crashed, the pilot survived. The second prototype, the Horten Ho V V-2, a single seater, was constructed in a conventional way, as far as the material and the control systems are concerned. During flight tests the aircraft showed excellent handling characteristics but remained grounded as WW II proceeded (Ref.:  19)