Dornier Do 335 Pfeil
The Dornier Do 335 Pfeil was a German heavy fighter of the Second World War built around two engines mounted in line in one fuselage, the front one pulling and the rear one pushing. The layout made it one of the fastest piston-engined aircraft ever flown, but it arrived too late and in too small numbers to see combat, and only one example survives, in the Smithsonian's collection.
Why It Mattered
The Dornier Do 335 Pfeil (Arrow) was a heavy fighter built around an arrangement no other production fighter used: one engine in the nose pulling the aircraft forward and a second in the tail pushing it from behind. Claudius Dornier had patented the push-pull engine layout in 1937, reasoning that it offered the power of two engines with less drag and better manoeuvrability than a conventional twin. The result was one of the fastest propeller-driven aircraft ever flown: German sources claimed a Do 335 reached 763 km/h (474 mph) in level flight, above the official world speed record of the time. Yet the type came too late and in too small numbers to influence the war it was built for.
Design Notes
Two Daimler-Benz DB 603 engines, each delivering about 1,750 hp, powered the Do 335, the rear engine driving its pusher propeller through a long shaft. Because both engines sat on the centreline, the aircraft did not yaw to one side if one failed, a familiar hazard in wing-engined twins. Dornier had proven the remote pusher arrangement before the war on a small test aircraft, the Göppingen Gö 9. Escape took engineering of its own: the tail fin and rear propeller could be blown off with explosive bolts so the pilot could eject clear of them. The design had real weaknesses, though — the buried rear engine overheated often, and the aircraft's great weight put constant strain on the landing gear.
Operational History
The prototype completed its first flight in September 1943, after the Luftwaffe's need for multi-role fighters revived Dornier's push-pull proposal, first submitted that January as a fast bomber. Orders covered prototypes, pre-production aircraft and a small production run, but engine deliveries and Germany's collapsing position kept output low: Dornier finished building as many as 48 aircraft, and another nine were under construction when the war ended. No Do 335 ever flew in combat. The type's only reported brush with Allied fighters came in April 1945, when French ace Pierre Clostermann, leading a flight of four Hawker Tempests over northern Germany, claimed the first Allied combat encounter with a Pfeil: an aircraft at treetop height that turned away and outran them.
Afterlife
A single Do 335 remains today: a preproduction A-0, the second such aircraft built, which was shipped to the United States after its capture to be used for testing and evaluation. It was donated to the Smithsonian's National Air Museum in 1961 but spent years in outdoor storage before returning to Germany, where Dornier restored the airplane in 1975. This object is on display today at the Steven F. Udvar-Hazy Center in Virginia.