Aviation Archive Issue 25 - 2016 UK

(Jacob Rumans) #1



s the conflict in Europe drew to a
close, a powerful new twin-engined
fighter was preparing to enter
service with the Luftwaffe. It was unlike
anything the Allied pilots had ever seen
before and it had the potential to ravage
the large bomber formations pounding
Germany. This innovative machine was the
Dornier Do 335, the fastest piston-engined
aircraft of its time.
What made the Dornier Do 335 fighter
unique amongst its twin-engined peers in
World War 2, was its low-drag push-pull engine
configuration. Powered by a pair of liquid-
cooled engines of 1,750hp, one in the nose and
the other in the tail, Germany claimed that the
Do 335 flew at a speed of 474mph (846km/h)
in level flight at a time when the official world
speed record was 469mph (755 km/h).
Aircraft designers are constantly seeking to
maximise engine power and minimise drag. The

increased power resulting from the adoption
of a twin-engined layout, is normally partially
offset by the increased drag and reduced
manoeuvrability. An alternative arrangement,
with the two engines mounted fore-and-aft
in tandem is known as centre-line thrust.
The obvious benefits of this layout include
reduced frontal area, an aerodynamically clean
wing and the elimination of the asymmetry
problems associated with engine failure. This
configuration had always appealed to Prof
Claude Dornier and could be tracked back to
his early designs. During World War 2 the RLM
(German Aviation Ministry) wanted to support
development of push-pull aircraft but initially
only as seaplanes and bombers. Accordingly,
Dornier proceeded with a Schnellbomber (fast
bomber), designated Do 335. However, in the
Autumn of 1942, Dornier was informed that
the bomber was no longer required, but that
the Do 335 was to be redesigned as a multi-

Dornier Do 335 Pfeil

role aircraft capable of duties as a single-seat
fighter bomber, high speed reconnaissance,
heavy fighter, and two seat night and all-
weather interceptor. Dornier set to work and
the prototype Do 335 V-1 (‘V’ for Versuchs or
experimental) was completed by September

  1. Aside from its unusual engine layout,
    the design incorporated several other unusual
    features. These included a reversible-pitch
    tractor airscrew, to shorten the rather long
    landing run; a wing leading edge de-icing
    system; hydraulically operated flaps; and
    a tunnel radiator for the rear engine. 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. For a fighter,
    the Do 335 was big and very heavy being
    powered by two Daimler-Benz DB-603 V-12

Above: Although given the nickname ‘Pfeil’ (arrow) by Dornier test pilots, on account of its speed,
service pilots quickly dubbed it ‘Ameisenbär’ (ant-eater) because of its long nose. Note the blisters
added to the cockpit canopy to house small mirrors to improve rearward vision.
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