Twin engine, pusher / puller, fighter / bomber; grey/green, green; late World War II development.
The Dornier Do 335 belongs in the small group of aircraft whose performance put them at the pinnacle of piston-engine aircraft development because it was one of the fastest aircraft powered by a piston engine ever flown. The Germans claimed that a pilot flew a Do 335 at a speed of 846 km/h (474 mph) in level flight at a time when the official world speed record was 755 km/h (469 mph). Two liquid-cooled engines each developing about 1,750 hp powered the Do 335. Dornier mounted one engine in the nose and the other in the tail in a unique low-drag push-pull configuration. This innovative design also featured an ejection seat, a tail fin which the pilot could jettison, and tricycle landing gear. For a fighter airplane, the Do 335 was enormous: tall enough that a person of normal height could walk beneath it and very heavy at 9,600 kg (21,000 lb) loaded. Serious flaws also plagued the design. The rear engine overheated often and the landing gear was very weak and prone to failure.
Claudius Dornier had patented the push-pull engine layout in 1937, which was innovative because if offered the power of two engines but less drag and greater maneuverability than other twin-engine configurations. The RLM (German Aviation Ministry) wanted to support development of push-pull aircraft but initially only as seaplanes and bombers. By 1942, the Luftwaffe needed multi-role fighters and after submitting a proposal in January 1943 for a Schnellbomber (fast bomber), Dornier build a prototype Do 335 V-1 (‘V’ for Versuchs or experimental) and the aircraft fighter in September 1943. Following initial testing, the RLM ordered 14 prototypes, ten preproduction aircraft with the suffix designation A-0, eleven production A-1 single-seat aircraft, and 3 A-10 and A-12 two-seat trainers.
Dornier selected two Daimler-Benz DB-603 V-12 cylinder engines to propel the four different versions of the Do 335. Each engine displaced 44.5 liters (2,670 cu in) and weighed 910 kg (2,006 lb). Unlike conventional twin-engine aircraft with wing-mounted engines, the Do 335 would not yaw sharply to one side if one engine failed, and single-engine flying speed remained respectable at about 620 km/h (345 mph). Pilots reported exceptional flight performance in acceleration and turning radius, and docile handling with no dangerous spin characteristics. In an emergency, however, the pilot could detonate explosive bolts and jettison the pusher three-blade propeller and dorsal fin to increase the chances of successfully bailing out using the pneumatic ejection seat. When fired, the seat pushed the pilot away from the aircraft with a force of 20 Gs.
Dornier finished building as many as 48 Do 335 airplanes and another nine or so were under construction when the war ended. One of many plans issued by the RLM called for Dornier to build 310 Do 335s by late 1945. Although several pre-production aircraft were issued to combat conversion units about 10 months before the war ended, no pilots flew Do 335s in combat. Only one example of the first production version Do 335A-1 left the Dornier line at Friedrichshafen just before the war ended. It was armed with one 30 mm MK-103 cannon (70 rounds were carried) firing through the propeller hub and two 15 mm MG-151/15 cannon (200 rounds per gun) firing from the top cowling of the forward engine. The aircraft was also equipped to carry an internal bomb load of 500 kg (1,100 lb).
The NASM displays at the Steven F. Udvar-Hazy Center the second Do 335 A-0 built. Dornier designated this airframe construction number 240102 and gave it the aircraft identification code VG + PH and A-02. Crafts persons completed the aircraft at Dornier's plant at Mengen, Germany, on 30 September 1944, and then test-flew the airplane during the winter of 1944-45. From 20-23 April 1945, German test pilot Hans Werner Lerche flew the Do 335 from Rechlin back to Oberpfaffenhofen near Münich, via Prague, Czechoslovakia, and Lechfeld, Germany. Allied forces found the Do 335 at Oberpfaffenhofen on April 29.
In mid-June, pilots ferried two Do 335s, including the NASM aircraft piloted by German test pilot Hans Padell, from Oberpfaffenhofen to Cherbourg, France, for shipment to the USA aboard the British aircraft carrier HMS Reaper, along with other captured German aircraft and equipment for technology evaluation. Following U. S. Navy testing from 1945-48, the navy transferred the Do 335 to the Smithsonian's National Air Museum in 1961. The Do 335 remained stored at Naval Air Station Norfolk until 1974 when the Smithsonian returned it to Oberpfaffenhofen, Germany, where the Dornier company preserved and restored the airplane in 1975. Dornier craftsmen, many of them factory employees since World War II, were surprised to find still attached to the aircraft the explosive bolts designed to blow off the tail fin and rear propeller. Dornier displayed the preserved airplane at the May 1976 Hannover Airshow, and then moved the artifact to the Deutsches Museum in Munich until the aircraft was returned to the Paul E. Garber Facility for storage in 1986.