TYPE: Heavy Fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Daimler-Benz DB 603A liquid-cooled engines, rated at 1,725 hp each

PERFORMANCE: 475 mph

COMMENT: The Dornier Do 335 “Pfeil” (“Arrow”) was a WW II heavy fighter built by the Dornier Company. It’s performance was much better than any 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 Luftwaffe’s 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 origins of the Dornier Do 335 trace back to WW I when Claude Dornier designed a number of flying boats featuring remotely driven propellers and later, due to problems with the drive shafts, tandem engines. Tandem engines were used on most of the multi-engine Dornier flying boats that followed, including the highly successful Dornier Do J “Wal” (“Whale”) and the gigantic Donier Do X. The remote propeller drive, intended to eliminate parasitic drag from the engine entirely, was tried in the innovative but unsuccessful Dornier Do 14, and elongated, tubular drive shafts as later used in the Do 335 saw use in the rear engines of the four-engine, twinned tandem-layout Dornier Do 26 flying boat.
There are many advantages to this design over the more traditional system of placing one engine on each wing, the most important being power from two engines with the frontal area (and thus drag) of a single-engine design, allowing for higher performance. It also keeps the weight of the twin power plants near, or on, the aircraft centerline, increasing the roll rate compared to a traditional twin. In addition, a single engine failure does not lead to asymmetric thrust, and in normal flight there is no net torque, so the plane is easy to handle. The choice of a full “four-surface” set of cruciformly tail surfaces in the Do 335’s rear fuselage design, included a ventral vertical fin-rudder assembly to project downwards from the extreme rear of the fuselage, in order to protect the rear propeller from an accidental ground strike on takeoff. The presence of the rear pusher propeller also mandated the provision for an ejection seat for safe escape from a damaged aircraft, and designing the rear propeller and dorsal fin mounts to use explosive bolts to jettison them before an ejection was attempted — as well as twin canopy jettison levers, one per side located to either side of the forward cockpit interior just below the sills of the five-panel windscreen’s sides, to jettison the canopy from atop the cockpit before ejection.
In 1939, Dornier was busy working on the P.59 high-speed bomber project, which featured the tandem engine layout. In 1940, he commissioned a flying test bed, closely modeled on the airframe of the early versions of the twin engine Dornier Do 17 bomber but only 40% of the size of the larger bomber, with no aerodynamic bodies of any sort on the wing panels and fitted with a retractable tricycle landing gear to validate his concept for turning the rear pusher propeller with an engine located far away from it and using a long tubular driveshaft. This aircraft, the Göppingen Gö 9, built by , Schrempp-Hirth, a small sailplane company, showed no unforeseen difficulties with this arrangement, but work on the Dornier P.59 was stopped in early 1940 when the RLM ordered the cancellation of all projects that would not be completed within a year or so.
In May 1942, Dornier submitted an updated version his design as the Dornier P.231, in response to a requirement for a single seat, “Schnellbomber” -like high-speed bomber/intruder. P.231 was selected as the winner after beating rival designs from Arado, Blohm & Voss and Junkers, development contract was awarded as the Dornier Do 335. In autumn 1942, Dornier was told that the Do 335 was no longer required as a “Schnellbomber”, and instead a multi-role fighter based on the same general layout would be accepted. This delayed the prototype delivery as it was modified for the new role.
The Dornier Do 335 V1 first prototype flew in October 1943 and initial trials revealed essentially good handling characteristics. Acceleration was particularly favourable and the turning circle was rather better than had been anticipated. The use of a nose-mount annular radiator for the forward engine (much like a Junkers Jumo 211-powered Junkers Ju 88, or Jumo 213-powered Focke-Wulf Fw 190D-9) and a ventral-fuselage mount air-scooped radiator installation for cooling the rear engine (appearing like that on a North American P-51 “Mustang”) was distinctive.
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 Do 335 V2 was completed and made its first flight on December 1943, followed by the third Do 335 V3 on January 1944. In mid January 1944, RLM ordered five more prototypes, one to be built as Do 335A-6 night fighter. By this time, more than 60 hours of flight time had been put on the Do 335 and reports showed it to be good handling characteristics, but more importantly, it was a very fast aircraft. Even with one engine out, it reached about 350 mph.
Thus 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.
On 23 May 1944, as part of the developing “Jägernotprogramm” (“Emergency Fighter Program”) directive, maximum priority was given to Do 335 production. Furthermore, the decision was made, along with the rapid shut-down of many other military aircraft development programs, to cancel the Heinkel He 219 night fighter, which also used the DB 603 engines, and use its production facilities for the Do 335 as well. However, Ernst Heinkel managed to delay, and eventually ignore, its implementation, continuing to produce examples of the He 219A.
At least 16 prototype Do 335s were known to have flown as well as Muster-series prototypes on a number of DB603 engine subtypes. The first preproduction Do 335A-0s were delivered in July 1944 to the “Erprobungskommando 335” (“Proving detachment 335”) formed for service evaluation purposes. Approximately 22 preproduction aircraft were thought to have been completed and flown before the end of WW II including approximately 11 Do 335A-1 single-seat fighters of which two examples had been converted to a trainer version Do 335A-12 for training purposes (Ref.: 7., 24).

TYPE: Interceptor, fighter

ACCOMMODATION: Pilot only

POWER PLANT: One Daimler-Benz DB 601A liquid-cooled engine, rated at 1,175 hp

PERFORMANCE: 370 mph app.

COMMENT: The designation Messerschmitt Me 209 was used for two separate projects during World War II. The first was a record-setting, single-engine race aircraft, for which little or no consideration was given to adaptation for combat (Messerschmitt Me 209 V1). The second Me 209 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.
In late 1939, after three prototypes of the record-breaking aircraft were built the fourth prototype, the Messerschmitt Me 209 V4, was adapted to a fighter aircraft. The fuselage was essentially similar to that of the record-speed aircraft but the vertical tail surfaces were substantially increased in area, the main undercarriage legs were shortened, an entirely new wing was fitted, and the maximum gross weight was reduced.
For initial flight trials, the Me 209 V4 was fitted with a standard Daimler-Benz DB 601A engine and retained the surface evaporation cooling system employed by its  high-speed predecessors, but this system was far from perfection and continuously troublesome, and after the eighth test flight was removed  and replaced by shallow, low drag radiators beneath the inboard wing panels. The resumption of flying trials immediately revealed inadequacy of the cooling provided by the underwing radiators, and the handling characteristics of both on the ground and in the air proved extremely poor. By 1940, the overall wing span had been increased and both horizontal and vertical tail surfaces had been enlarged, but trial revealed no major improvement of the characteristics of the fighter.
With each successive modification weight escalated and performance diminished, and as the Me 209 V4 was by now decidedly underpowered, the DB 601A was replaced by a DB 601N affording 1,200 hp for take-off. But troubles still continued and further tests proved that speed performance was marginally lower than that of the standard Messerschmitt Me 109E. Finally all further development was abandoned.
However, combat actions with British Supermarine “Spitfires” showed an urgent need for a successor of the Luftwaffe’s Messerschmitt Me 109. So the Messerschmitt design bureau had been engaged in developing a modernized, more powerful derivative of the Me 109 and the RLM transferred the designation Me 209 to the new fighter which should employ a large portion of a standard Me 109 components. In fact, at the outset it was envisaged that there would be approximately 65 per cent airframe communality between the Me 109G and what now referred to as Messerschmitt Me 209-II (Ref.: 7).

TYPE: Prototype of Me 262

ACCOMMODATION: Pilot only

POWER PLANT: Two BMW P.3302 (BMW 003) turbojet engines, rated at 550 kp thrust each, plus one Junkers Jumo 210G liquid-cooled engine, rated at 720 hp

PERFORMANCE: 350 mph

COMMENT: Several years before World War II, the Germans foresaw the great potential for aircraft that used the turbojet engine constructed by Hans Joachim Pabst von Ohain, engineer with the Heinkel Company, in 1936. After the successful test flights of the world’s first jet aircraft—the  Heinkel He 178, Messerschmitt and his design bureau adopted the turbojet engine for an advanced fighter aircraft. As a result, the Messerschmitt Me 262 was already under development as “Projekt 1065” (P.1065) before the start of World War II. The project originated with a request by the Reichsluftfahrtministerium (RLM, Ministry of Aviation) for a turbojet aircraft capable of one hour’s endurance and a speed of at least 530 mph. Dr. Waldemar Voigt headed the design team, with Messerschmitt’s chief of development, Robert Lusser, overseeing.
Plans were first drawn up in April 1939, and the original design was very different from the aircraft that eventually entered service, with wing root-mounted engines, under development by BMW as 003 or by Junkers as Jumo 004, rather than podded ones, when submitted in June 1939. The progression of the original design was delayed greatly by technical issues involving the new turbojet engine. Because the engines were slow to arrive, Messerschmitt moved the engines from the wing roots to underwing pods, allowing them to be changed more readily if needed; this would turn out to be important, both for availability and maintenance. Since the BMW 003 jets proved heavier than anticipated, the wing was swept slightly, by 18.5°, to accommodate a change in the center of gravity. Funding for the turbojet engine program was also initially lacking as many high-ranking officials thought the war could easily be won with conventional aircraft.
Test flights began on 18 April 1941, with the Me 262 V1 example, bearing its “Stammkennzeichen” (radio code letters) of PC+UA, but since its intended BMW 003 turbojets were not ready for fitting, a conventional Junkers Jumo 210 piston engine was mounted in the V1 prototype’s nose, driving a propeller, to test the Me 262 V1 airframe. After successful trials demonstrating good flying characteristics of the design two prototypes of the BMW P.3302 turbojet engines, forerunner of the BMW 003 turbojet engine, were installed.  The Jumo 210 piston engine was retained for safety, which proved wise – so often reported in literature – as both turbojet engines failed during the first flight and the pilot had to land using the nose-mounted engine alone. Original test-flight protocols published some years ago show reasonable doubt on that report.
In total the Messerschmitt Me 262 V1 successfully completed 74 flights but only one under turbojet power. The prototypes V2 through V4 were purely turbojet driven, but with the more powerful Junkers Jumo 004 turbojet engines.
The V1 through V4 prototype airframes all possessed what would become an uncharacteristic feature for most later jet aircraft designs, a fully retracting conventional landing gear setup with a retracting tailwheel. Indeed, the very first prospective German “turbojet fighter” airframe design ever flown, the Heinkel He 280, powered by a Heinkel HeS 8A turbojet engine, used a retractable tricycle landing gear from its beginnings, and flying on turbojet power alone as early as the end of March 1941. From prototype Me 262 V6 onwards all aircraft featured a fully-retractable, hydraulically-operated tricycle undercarriage. Dubbed unofficially the “Schwalbe” (“Swallow”), the first production sub-type off the new warplane, the Messerschmitt Me 262A-1a single-seat interceptor fighter entered service with the “Erprobungskommando (EKdo) 262” at Lechfeld in July 1944  (Ref.: 7, 24).

TYPE: Rocket-powered interceptor test bed

ACCOMMODATION: Pilot only

POWER PLANT: One Walter R II-203b bi-fuel liquid rocket, rated between 150 to 750 kp

PERFORMANCE: 550 mph

COMMENT: In early 1941, based on the success by the DFS 194, production of a prototype series, known as the Messerschmitt Me 163, began. Secrecy was such that the RLM’S “GL/C” airframe number, 8–163, was actually that of the earlier, pre-July 1938 Messerschmitt Bf 163. It was thought that intelligence services would conclude any reference to the number “163” would be for that earlier design. Five prototypes (V1 to V5) were ordered designated Messerschmitt Me 163A “Komet” (“Comet”).
In May 1941 the Messerschmitt Me 163A V4 was shipped to Peenemünde to receive the Walter HWK RII-203 engine. By 2 October 1941, the Me 163A V4, bearing the radio call sign letters, or Stammkennzeichen, “KE+SW”, set a new world speed record of 624.2 mph. Piloted by Heini Dittmar, the fully tanked up aircraft was towed to an altitude of 13,120 ft behind a Messerschmitt Me 110C. After casting-off from the tow-plane, the rocket engine was fired. At about Mach 0.84 compressibility effects resulted in a sudden loss of stability, and the Me 163A V4 went into a dive. Dittmar promptly cut the rocket motor, the aircraft decelerating rapidly and full control being restored. The aircraft was landed on skids with no apparent damage to the aircraft during the attempt.
During further flight testing, the superior gliding capability of the Me 163A proved detrimental to safe landing. As the now un-powered aircraft completed its final descent, it could rise back into the air with the slightest updraft. Since the approach was unpowered, there was no opportunity to make another landing pass. For production models, a set of landing flaps allowed somewhat more controlled landings. This issue remained a problem throughout the program. Nevertheless, the overall performance was tremendous, and plans were made to put the Messerschmitt Me 163 squadrons all over Germany in 40-kilometre rings (25 mi) around any potential target. Development of an operational version was given the highest priority.
Five prototype 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”.

Note: Some postwar aviation history publications stated that the Messerschmitt Me 163A V3 (CD+IL) was thought to have set the record. The 1,004 km/h record figure would not be officially approached until the postwar period by the new British and American turbojet-powered aircraft. It was not surpassed (except by the later Me 163B V18 in 1944, but seriously damaged by the attempt) until the American Douglas D-558-I “Skystreak” turbojet-powered research aircraft did so on 20 August 1947 with no damage (Ref.: 24).