The Dornier Do 335 ''Pfeil'' ("Arrow") was a
heavy fighter
A heavy fighter is a historic category of fighter aircraft produced in the 1930s and 1940s, designed to carry heavier weapons, and/or operate at longer ranges than light fighter aircraft. To achieve performance, most heavy fighters were twin-eng ...
built by
Dornier for Germany during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. The two-seater trainer version was called ''Ameisenbär'' ("anteater"). The ''Pfeil''s performance was predicted to be better than other twin-engine designs due to its unique
push-pull configuration
An aircraft constructed with a push-pull configuration has a combination of forward-mounted tractor (pull) propellers, and backward-mounted ( pusher) propellers.
Historical
The earliest known examples of "push-pull" engined-layout aircraft incl ...
and the lower
aerodynamic drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fl ...
of the in-line alignment of the two engines. It was Nazi Germany's fastest piston-engined aircraft of World War II. The ''
Luftwaffe
The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...
'' 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.
Design and development
The origins of the Do 335 trace back to
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
when
Claude Dornier
Claude (Claudius) Honoré Désiré Dornier (born in Kempten im Allgäu on 14 May 1884 – 5 December 1969) was a German-French airplane designer and founder of Dornier GmbH. His notable designs include the 12-engine Dornier Do X flying boat, ...
designed a number of
flying boat
A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...
s 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
Do J ''Wal'' and the gigantic
Do X. The remote propeller drive, intended to eliminate
parasitic drag
Parasitic drag, also known as profile drag, is a type of aerodynamic drag that acts on any object when the object is moving through a fluid. Parasitic drag is a combination of form drag and skin friction drag. It affects all objects regardless of ...
from the engine entirely, was tried in the innovative but unsuccessful
Do 14, and elongated, tubular drive shafts as later used in the Do 335 saw use in the rear engines of the four-engined, twinned tandem-layout
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 powerplants near, or on, the aircraft centerline, increasing the