Submarines and their Weapons - Aircraft of World War II

through 90 degrees to bring them to the position of
pusher propellers. Such an arrangement (but employing
more efficient tractor propellers) was not to be
successfully introduced until Boeing-Vertol perfected
the V-22 Osprey in the late 1980s. The Fa 269 was
really little more than a flight of fancy, and it is to be
doubted if the technology of the day could actually
have realised it. The Fa 284 was much more practical,
being, in effect, a stretched version of the Fa 223, with
a fuselage which was largely of lattice construction
and twin 1600hp BMW 801 engines. Tt was designed
to carry heavy loads underslung, in exactly the same
way as its 1970s equivalent, the Sikorsky S-60 (CH-
54B) 'Flying Crane', did. Some parts are said to have
been manufactured before the project was cancelled
in late 1943 and plans were drawn up to produce a
twin Fa 223, essentially two aircraft joined, in-line, by
a short fuselage section. This section is known to have
been produced, but the complete aircraft was not.
By far the most adventurous of Professor Focke's
designs was presented under the auspices of Focke-
Wulf rather than Focke Achgelis. Known as the
'Triebflügel' ('Thrustwing'), this was a tail-sitting
VTOL (Vertical Take-Off and Landing) aircraft which
derived its lift from three wings which rotated around
the fuselage just aft of the cockpit, under the power of
tip-mounted ramjets giving about 840kg (18501b) of
thrust, the wings being brought up to operating speed
by three jettisonable rockets. In flight, the wings
would be rotated around their individual axes until
ROTARY-WING AIRCRAFT
they became conventional aerofoils as the aircraft
itself rotated until its axis was horizontal rather than
vertical. No real development work was ever done on
the concept, and the viability of the design is a matter
of speculation, but three tail-sitting VTOL aircraft
were built post-war, two in the USA and one in
France. The American designs, from Lockheed and
Convair, were somewhat more conventional, in that
they used fixed wings and contra-rotating propellers
in the nose, while the French SNECMA 'Coleopter'
was powered by a tail-mounted turbojet and had an
annular wing, control being achieved through four
swivelling fins. All three aircraft flew after a fashion,
but all projects were eventually cancelled. The objective
has since been achieved by vectoring the thrust of
a turbojet in a more-or-less conventional airframe.
ANTON FLETTNER
Having turned his attention to the problems of rotarywing
flight in 1930, Anton Flettner first produced a
helicopter with two 30hp Anzani piston engines
mounted on the ends of two rotors, each turning a
two-bladed propeller. While this arrangement eliminated
the problems associated with torque (which the
Focke Achgelis designs overcame by means of two
contrarotating rotor sets, and which other designers,
Below: The Fl 282 was the most sophisticated of all
German helicopters of World War II. This later version -
captured by US forces - even had protection for the pilot.