V-1 Flying Bomb - Experimental and Long-range Variants

Experimental and Long-range Variants

Late in the war, several air-launched piloted V-1s, known as Reichenbergs, were built, but never used in combat. Hanna Reitsch made some flights in the modified V-1 Fieseler Reichenberg when she was asked to find out why test pilots were unable to land it and had died as a result. She discovered, after simulated landing attempts at high altitude where there was air space to recover, that the craft had an extremely high stall speed and the previous pilots with little high speed experience had attempted their approaches much too slowly. Her recommendation of much higher landing speeds was then introduced in training new Reichenberg volunteer pilots. The Reichenbergs were air-launched rather than fired from a catapult ramp as erroneously portrayed in Operation Crossbow.

There were plans, not put into practice, to use the Arado Ar 234 jet bomber to launch V-1s either by towing them aloft or by launching them from a "piggy back" position (in the manner of the Mistel, but in reverse) atop the aircraft. In the latter configuration, a pilot-controlled, hydraulically operated dorsal trapeze mechanism would elevate the missile on the trapeze's launch cradle some eight feet clear of the 234's upper fuselage. This was necessary to avoid damaging the mother craft's fuselage and tail surfaces when the pulse jet ignited, as well as to ensure a 'clean' airflow for the Argus motor's intake. A somewhat less ambitious project undertaken was the adaptation of the missile as a 'flying fuel tank' (Deichselschlepp) for the Messerschmitt Me 262 jet fighter, which was initially test-towed behind an He 177A Greif bomber. The pulse-jet, internal systems and warhead of the missile were removed, leaving only the wings and basic fuselage, now containing a single large fuel tank. A small cylindrical module, similar in shape to a finless dart, was placed atop the vertical stabilizer at the rear of the tank, acting as a centre of gravity balance and attachment point for a variety of equipment sets. A rigid tow-bar with a pitch pivot at the forward end connected the flying tank to the Me 262. The operational procedure for this unusual configuration saw the tank resting on a wheeled trolley for take-off. The trolley was dropped once the combination was airborne, and explosive bolts separated the towbar from the fighter upon exhaustion of the tank's fuel supply. A number of test flights were conducted in 1944 with this set-up, but inflight "porpoising" of the tank, with the instability transferred to the fighter, meant the system was too unreliable to be used. An identical utilisation of the V-1 flying tank for the Ar 234 bomber was also investigated, with the same conclusions reached. Some of the "flying fuel tanks" used in trials utilised a cumbersome fixed and spatted undercarriage arrangement, which (along with being pointless) merely increased the drag and stability problems already inherent in the design.

One variant of the basic Fi 103 design did see operational use. The progressive loss of French launch sites as 1944 proceeded and the area of territory under German control shrank meant that soon the V-1 would lack the range to hit targets in England. Air-launching was one alternative utilised, but the most obvious solution was to extend the missile's range. Thus the F-1 version developed. The weapon's fuel tank was increased in size, with a corresponding reduction in the capacity of the warhead. Additionally, the nose-cones of the F-1 models were made of wood, affording a considerable weight saving. With these modifications, the V-1 could be fired at London and nearby urban centres from prospective ground sites in the Netherlands. Frantic efforts were made to construct sufficient F-1s so that a large-scale bombardment campaign could coincide with the Ardennes Offensive, but numerous factors (bombing of the factories producing the missiles, shortages of steel and rail transport, the chaotic tactical situation Germany was facing at this point in the war etc.) delayed the delivery of these long-range V-1s until February/March 1945. Before the V-1 campaign ended for good at the end of the latter month, several hundred F-1s were launched at Britain from Dutch sites.

Almost 30,000 V-1s were made; by March 1944, they were produced in 350 hours (including 120 for the autopilot), at a cost of just 4% of a V-2, which delivered a comparable payload. Approximately 10,000 were fired at England; 2,419 reached London, killing about 6,184 people and injuring 17,981. The greatest density of hits were received by Croydon, on the southeast fringe of London. Antwerp, Belgium was hit by 2,448 V-1s from October 1944 to March 1945.