Thursday, February 19, 2015
The sole example of the Me 264, the original 'Amerikabomber', first flew in December 1942. Such close attention was paid to its aerodynamic properties that the joints in the wings and fuselage were filled with putty.
The Luftwaffe, we may recall, was intended as a tactical, rather than a strategic, air force, unlike the USAAF and the RAF, and it never operated really large, long-range bomber aircraft, like the American B-17 Flying Fortress or B-24 Liberator, or the British Lancaster, in any substantial numbers. It had aircraft, like the Focke-Wulf FW 200 'Condor' and the Junkers Ju 290 (though the former was designed as a civilian airliner and the latter was a hasty transformation of another), which were capable of flying very long distances, but these were intended primarily for ultra-long-range maritime reconnaissance, and while they did carry bombs (and variants of both carried glider bombs), they were unsuitable for use in combat conditions. Thus, when the USA declared war on Germany in December 1941, the Luftwaffe found itself without the means of attacking its new-found enemy, and the RLM immediately issued a specification for a suitable aircraft.
Three companies responded: Focke-Wulf with the Ta 400; Messerschmitt with the Me 264; and Junkers with the Ju 390. The Ta 400 was never built; the latter, which was little more than a Ju 290 stretched in wings and fuselage with two more engines, was reasonably straightforward, and the first prototype flew in August 1943. The second protype had a still longer fuselage and carried FuG 200 Hohentweil search radar and five 20mm cannon. On a test flight from Mont de Marsan on the Atlantic coast of France, near Bordeaux, it once approached to within 20km (12.4 miles) of New York before returning safely to base, thus validating the operational concept. A third prototype, this time a version able to carry 1800kg (39701b) of bombs, was begun but never completed.
In fact, certain individuals at the RLM had begun to contemplate the possibility of bombing New York long before the United States entered the war, and Willy Messerschmitt for one had begun to think about a design for a suitable aircraft. His company was thus well placed to satisfy the requirement when it was issued in December 1941, and the prototype Me 264 made its first flight just 12 months later. With enough fuel to reach New York and return safely (a flight of anything up to 30 hours!), it could carry 3000kg (66001b) of bombs, and still had enough capacity to carry 1000kg (22001b) of armour plating. It had two complete three-man crews with a sleeping area and galley, and an elaborate defensive armament of four 13mm machine guns and two 20mm cannon. Under overload conditions, the aircraft could be fitted with up to six solid fuel rockets to assist it to take off. A bewildering array of variants and variations were suggested, including one to tow an Me 328 glider fighter for protection, and another which would have been the flying testbed for a steam turbine powerplant. Two prototypes were begun; the first was destroyed in an air raid just as it was about to begin ground tests, but the second was completed and flew, being allocated to Transportstaffel 5, which operated other large aircraft types in the transport role. A version with greater wingspan and six engines was contemplated, but never produced. Thus the first round of the 'Amerikabomber' contest made no more than a token impact.
RLM, near the end of the war, had resurrected the 'Amerikabomber' programme, but the planemakers selected - Arado, Focke-Wulf, Heinkel, Junkers and Messerschmitt - had made little progress. Siegfried Kneymeyer then contacted the Horten brothers and asked them to turn their attention to a bomber with trans-Atlantic range. Not surprisingly, they came up with a flying wing, essentially an enlarged Ho IX, which they called the P. 18. All the would-be contenders were summoned to a conference at the RLM in February 1945, and the Horten design was selected for production. The brothers were instructed to work with designers from Junkers and Messerschmitt, but the proposed consortium soon fell apart when more conservative elements insisted on adding a large fin and hinged rudder to the design. Reimar Horten then went directly to Goring with a modified plan for the P. 18B, employing four HeS 011 engines in place of six Jumo 004s or BMW 003s, saving 1000kg (22001b) with little loss of thrust. The aircraft, he confidently predicted, would have a range of 11,000km (6835 miles) at 850km/h (530 mph) and fly at an altitude of 16,000m (52,500ft) with a 4000kg (88001b) bombload. He was told to go ahead and build it, but by that time the war had only 10 weeks to run and it is doubtful whether detailed plans were drawn up, though they may have been later, as both brothers continued to work in aviation for the rest of their lives, Walter eventually becoming a leading light in the new Luftwaffe, Reimar in the aircraft industry in Argentina.
Junkers had, in addition to Hans Wocke, two other extremely talented designers in Ernst Zindel and Heinrich Hertel. These three soon responded to the new-found interest in all-wing aircraft and proposed one such of their own as Project 130. It is suggested that Hertel had produced the Ju 287 design only as a means of gaining experience in the sort of aerodynamics required by the P. 130, but it is worth bearing in mind that he had acquired some relevant experience with the Ju 322. Similar in character to the Hortens' P. 18B, the P. 130 had a shorter range (around 5800km; 3600 miles), and was apparently intended to operate against targets in Soviet Asia and in England from bases in Prussia. The 'committee-modified' version of the P. 18A, with the addition of the long triangular tail fin, became the Junkers P. 140, with the range to carry 4.06 tonnes (4 tons) of bombs to New York. Like the P. 18B, it was ordered into production, but work had hardly begun before the underground factory in the Harz mountains where it was to have been built was overrun.