Submarines and their Weapons - Aircraft of World War II

SURFACE-TO-SURFACE MISSILES
Above: V1s were launched on ramps by steam catapults.
When they reached around 400km/h (250mph), their own
powerplants took over and the guidance system took them
in a gentle climb to their cruising altitude.
ordered Gerhard Fieseler to begin developing an airframe
for a flying bomb. In the meantime Argus carried
on developing the powerplant, Walter began work
on a catapult launching system, and Siemens set out
to produce a guidance system using an existing
autopilot as a basis.
The airframe was actually the work of Robert
Lusser who, we may recall, was involved in the original
P. 1065 project at Messerschmitt, and Willy
Fiedler. Development took 18 months, and it was
early December of 1942 before the first (unpowered)
example was launched from an Fw 200 'Condor' over
the test range at Peenemiinde-West, to be followed by
the first catapult launch on Christmas Eve. In one
form or another, a total of perhaps 350 missiles were
expended in the course of testing. At the start, testing
did not proceed smoothly. The situation was complicated
by the necessity to test all the components
together, which made fault isolation difficult, but
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eventually the design of the air intake and the fuelsupply
system were identified as the seats of the worst
problems, and when they were re-thought, the bomb
flew much more reliably. However, it flew considerably
more slowly than had been envisioned, at around
600km/h (370mph), which made it vulnerable to
interception by existing fighter aircraft. Consequently,
there was a non-stop programme to improve the Vl's
performance, both by upping the output of the Argus
109-014 motor (by injecting nitrous oxide into the
combustion chamber, for example) and by replacing it
with a more powerful unit such as the 109-044 or the
Porsche 109-005 turbojet - both of which produced
500kg (1 lOOlb) of static thrust - or by an unspecified
ramjet. By the war's end, experimental models were
flying at almost 800km/h (500mph). By then, they
were faced with much faster interceptors, such as the
jet-powered Gloster 'Meteor' which scored its first
combat victory on 4 August 1944 when it destroyed a
VI by tipping it over with its wingtip to destabilise it.
This was not as risky a manoeuvre as one might think,
and was deemed preferable to shooting the flying
bombs down at close range, with the attendant risk of
damage to one's own aircraft. In fact, the Vis were a
much easier target for guns on the ground than they
were for aircraft, since they flew straight and level and
at a fixed speed; more were destroyed by this means
than by any other.
DESIGN MODIFICATIONS
Not entirely surprisingly, the guidance system and its
installation proved to be problematic, too. The first
difficulty actually showed up before the Fi 103 airframe
was completed, and involved the positioning of
the engine vis-ä-vis the fuselage. Tests carried out
with engines mounted on Do 17 and Ju 88 aircraft
showed that the pulse action produced considerable
vibration, particularly if the exhaust stream passed
over the fuselage, and so the design was modified to
move the entire engine aft so that it overhung the tail
by some considerable extent. Close attention had to
be paid to the mountings, and eventually a system was
adopted which combined a pivoted yoke at the front
secured with a single pinned lug to the tail fin, both of
the mountings in rubber bushes. However, there were
still problems with vibration. The guidance system
itself relied on a gyroscope for control in all three
axes, linked to a master compass set to the desired
heading before launch for azimuth control, and an
aneroid barometer for altitude control. Corrections
were transmitted to the servo-motors acting on the