TYPE: Target defense interceptor. Project.

ACCOMMODATION: Pilot only, in seated position

POWER PLANT: Three Pabst/Lorin ramjets at wingtips, rated at 840 kp thrust each. For starting ramjets Walther 109-500 solid-fuel rockets were fitted to each ramjet, rated at 500 kp for 30 seconds each

PERFORMANCE: 621 mph (estimated)

COMMENT:  This Focke-Wulf Vertical Take-Off and Landing (VTOL) fighter/interceptor project was designed in September 1944, at the same time when the Heinkel Company worked on its VTOL-projects “Lerche” and “Wespe”. But in contrast to the latter two designs the propulsion system of the Focke-Wulf project was radical different. Three untapered wings rotated around the fuselage and had a gradually decreasing pitch towards the wingtips, thus acting like a giant propeller (“Triebflügel”). At the end of each wing was a Pabst ramjet. Since ramjets do not operate at slow speeds, the wing-rotor had to be driven by small Walter rocket engines, fitted to each ramjet pod. When the plane was sitting on its tail in the vertical position, the rotors would have functioned similarly to a helicopter. When flying horizontally, they would function more like a giant propeller. A cruciform empennage at the rear of the fuselage comprised four tail planes, fitted with moving ailerons that would also have functioned as combined rudders and elevators. A single large and sprung wheel in the extreme end of the fuselage provided the main undercarriage. Four small castoring wheels on extensible struts were placed at the end of each tail plane to steady the aircraft on the ground and allow it to be moved. The main and outrigger wheels were covered by streamlined clamshell doors when in flight. When taking off, the rotors would be angled to give lift as with a helicopter or, more accurately, a gyrodyne. Once the aircraft had attained sufficient altitude it could be angled into level flight. This required a slight nose-up pitch to provide some downward thrust as well as primarily forward thrust. Consequently, the four cannons in the forward fuselage would have been angled slightly downward in relation to the center line of the fuselage. The rotors provided the only significant lift in horizontal flight. To land, the aircraft had to slow its speed and pitch the fuselage until the craft was vertical. Power could then be reduced and it would descend until the landing gear rested on the ground. This would have been a tricky and probably dangerous maneuver given that the pilot would be seated facing upward and the ground would be behind his head at this stage. Unlike some other tail sitter aircraft, the pilot’s seat was fixed in the direction for forward flight. The spinning rotor would also obscure rear vision. Although the “Triebflügeljäger” project was not realized, a wind tunnel model was tested up to a speed of Mach 0.9 (Ref.: 17, 18, 23)

TYPE: Target defense interceptor. Project.

ACCOMMODATION: Pilot only, in prone position

POWER PLANT: Two Daimler-Benz DB 603E inline engines, rated at 2.400 hp each, driving contra-rotating propellers

PERFORMANCE: 497 mph

COMMENT: This Heinkel Vertical Take Off and Landing (VTOL) fighter/interceptor project was based on an earlier design, the Heinkel “Wespe” (Wasp). Work on the design started at the Heinkel Company in Vienna on February 25, 1945 and was completed on March 8, 1945. The “Lerche” (Lark) employed a ducted wing planform with contra-rotating propellers, powered by two Daimler-Benz DB 605E engines. This arrangement increased the effectiveness of the airscrews dramatically. During flight the pilot lied in a prone position in the extreme nose, while standing upright during take-off and landing. Projected armament was two MK 108 30mm cannon. The end of the war brought any realization to a termination. After the war this idea of a tail sitter was developed further by the US Navy, e. g. Convair XFY-1 Pogo and Lockheed XFV-1 Salmon (Ref.: 16).

TYPE: Fighter, interceptor. Project.

ACCOMMODATION: Pilot only

POWER PLANT: Heinkel-Hirth HeS 011, rated at 1,300 kp

PERFORMANCE: 612 mph at 22,970 ft

COMMENT: However, there is some evidence that a further production version of the Me P.1101 was on Messerschmitt’s drawing boards. All over dimensions, turbojet engines, tricycle undercarriage etc. are unchanged to its predecessor, the wing was swept back to 40 degree and a normal or horizontal tail unit – “T-Tail” was provided. Cockpit armor was fitted and up to four Kramer X-4 air-to-air guided missiles could be carried.

RUHRSTAHL/KRAMER X-4

The Kramer X-4 was the first air-to-air guided missile that entered the production lines. It featured a tapering, cigar-shaped fuselage, with four small swept wings and four smaller tail fins. At the ends of two of the opposing wings were small pods which held the wires that unwound during the X-4’s flight. On the wing tips of the other two main wings were simple flares to aid the pilot in keeping the X-4 on the intended path. The tail unit contained small spoilers which could control the missiles pitch and yaw. Power was supplied by the BMW 109-548 liquid-fuel rocket engine with 1,600 kp thrust for 33 seconds. A warhead weighing 20 with a destructive blast radius of 25 feet was mounted in the nose of the missile, being detonated by the pilot, impact or by an acoustical proximity fuse, tuned to the pitch of the bomber’s propellers. First air launched test took place on August, 1944 by a Focke-Wulf  Fw 190. Tests continued through early February 1945, also by Junkers Ju 88s as well as by a Messerschmitt  Me 262 jet fighter with two X-4 missiles under the wings outboard of the jet nacelle, but were not launched  (Ref.: 16).