HEINKEL WESPE & LERCHE II

(1944-1945)

By Rob Arndt


The VTOL point defense interceptor Wespe (Wasp) was designed at the Vienna Heinkel works in late 1944 for use around the factory complexes. As such, the exotic tail-sitter could be positioned almost anywhere in anticipation of attack, the need for a proper airfield not required

The Wespe possessed a main circular wing beyond which were attached two small wings below the cockpit with the pilot sitting in the normal seated position in the nose with excellent vision provided by a large blown canopy. Two 30mm MK-108 cannon were envisioned as armament for this interceptor, to be located in blisters on each side of the cockpit.

For power, the Wespe was propelled by a lone 2000 hp DB PTL 021 turboprop driving a six-blade propeller with additional thrust provided by the jet exhaust. The engine was fed by an air intake located below the cockpit.

Upon take-off the three landing gear were “podded” to aerodynamically improve the Wespe’s flight performance.

But as the end of the war drew near, the project was not further developed; instead, a newer, more aerodynamic improved version was proposed - the Lerche (Lark) II

The Lerche (Lark) II was based largely on the Heinkel Wespe, but with a far less complicated engine configuration and various other technical improvements for ease of construction. The Heinkel designers Dr-Ing. Kurt Reiniger and Dr-Ing. Gerhard Schulz began the C-version design on February 25, 1945 and finished it by March 8, 1945.

The original Lerche I was to be a dedicated ground-attack aircraft but the nature of aerial combat late in the war meant a more practical application as a point defense interceptor.

The Lerche kept the channeled circular wing but this time the power plants were tandem DB 605Ds driving counter-rotating propellers. The VTOL tail-sitter retained the two 30mm MK-108 cannon but this version had the pilot lying prone for better overall control and supreme visibility with another bubble canopy. This flying position is ideal in that the man and machine become much more of a single unit and gives the pilot a feeling of being able to truly fly. With inspired confidence, attacking the bomber formations and other escorts would have been psychologically beneficial to the German pilot.

The only drawback to this type of design is the engine output damaging effect to the fuselage structure over time. Otherwise, the Lerche would have been an outstanding VTOL interceptor with the unique ability to land anywhere in German-held territory. Schwarzwald deployment would have been ideal for this type of machine.

But time was not on Germany’s side and the Lerche II was never built. It did, however, serve as inspirations for Allied postwar prototype test aircraft. Germany itself also proposed a range of tail-sitters including the Heinkel 231, in 1956.

Technical Data (Lerche II/C Version):

Crew: Pilot only
Powerplants: 2x 2,000 hp DB605 engines
Propeller diameter: 4.0 meters
Wing max. width: 4.55 meters
Wing chord: 1.50 meters
Wing area: 12.0 meters squared
Fuselage width: 1.25 meters
Fuselage length: 9.4 meters
Length overall: 10.0 meters (wheels included)
Surface area: 102.8 meters squared
Fuel Weight; 600 kg
Loaded weight: 5,600 kg
Max. Speed: 497 mph
Armament: 2x 30mm MK-108 cannon























Heinkel "Wespe" / "Lerche II"

Specific Features: Looking more like a submarine, the Heinkel "Lerche II" was a German attempt at creating a VTOL interceptor. The Germans had pioneered the development of practical helicopters earlier in the war, but what few of these were built generally filled the role of a more flexible observation platform or courier aircraft. With bombs raining down all over the German homeland there was more than a little need for an interceptor force that could be based at minimal facilities near important factories. Building on some of the basic concepts of rival designer Focke-Wulf's "Triebflügel" VTOL aircraft, Heinkel began work developing their own "Wespe".

The "Wespe" project evolved into the more-streamlined "Lerche II" interceptor. Equipped with massive variable-pitch contra-rotating propellers on the center of the fuselage, the aircraft's propulsion was essentially a giant warning to the pilot not to even think about bailing out. The aircraft would have launched standing upright like a rocket, but instead of using a blast of fire to take off the pilot would have simply adjusted the thrust and pitch of the rotors as with a helicopter. To land the vehicle this procedure would have been reversed, only with much greater difficulty since it it rested on three ridiculously small feet. The pilot's unenviable task was to lay prone in the cockpit, fighting enemies face-first with a bullet-proof canopy the only thing between him and a bloody end. The armament for the Lerche was a pair of 30mm cannons, one mounted on each side of the fuselage near the cockpit; adequate but certainly not spectacular.

History: Work began on developing the "Wespe" in 1944 and continued on to the "Lerche II" in 1945. A familiar story repeated itself as advancing Allied armies put the kibosh on any further work on the project. Had the "Lerche II" ever flown it likely would have been an interesting but ultimately ineffective design. It would have been difficult to land under the best of circumstances, totally outgunned when going up against multiple fighters, and fast but with poor maneuverability. All three of these features were key ingredients of many of the Nazi's late-war aircraft like the Komet rocket-plane. Also like the Komet, which was prone to fuel explosions if a bullet so much as looked at it (and even more prone to exploding on landing), the "Lerche II" would have left the pilot very vulnerable to any attempt to shoot the aircraft down. The massive props might have survived a flyby from a P-51, but the pilot would have probably been blasted to pieces inside his glass bubble.




Range of postwar German tail-sitters from Bolkow, Heinkel 231, Messerschmitt, and Focke-Wulf 860


Bolkow P110

Design concept for a high-altitude supersonic fighter-interceptor (the VJ 101). Requirements by the Bundesministerium der Verteidigung (BMVg, "Ministry of Defense") on February 2, 1957.

The P 110.0 design, was an unmanned guided weapons system based on the SNECMA C.450 Coléoptère. It was soon apparent that it would not be able to meet the ambitious performance requirements, so Bölkow concentrated on working with Heinkel and Messerschmitt on their designs.

Variant A

Power: Bristol Orpheus 12 engine with 3,090 kg (6,800 lb) of thrust

Weight: 3,925 kg (8,650 lb)

Variant B


Power: Bristol Orpheus 12 engine with 3,090 kg (6,800 lb) of thrust supplemented by two General Electric J85 engines, each producing 2,000 kg (4,400 lb) of thrust in afterburner.

Weight: 3,600 kg (7,900 lb)

Variant C

Power: single General Electric J85 engine; without afterburning it produced only 1,200 kg (2,650 lb) of thrust,
but this was augmented with a rocket motor for take-off.
Weight: 1,660 kg (3,500 lb)



Heinkel He-231

Power: four GE J85 Wingspan: ca. 6 m
Length: ca. 10 m
Height: ca. 4.1 m
Empty Weight: 4,600 kg (10,150 lb)
Payload: 450 kg (1000 lb)
Maximum VTOL Weight: 7,460 kg (16,450 lb)


Messerschmitt Me X1-21 TailsitterMesserschmitt Me X1-21 Tailsitter

 

Fw-860 VTOL

Power: 2 x Pratt & Whitney (P&W) JTF 10 turbojets, each weighing 2,100 lb (950 kg) and producing 10,500 lb (4,760 kg) thrust
Range: 250 nm (460 km)
Wingspan: 6.48 m (21.3 ft)
Length: 10.8 m (35.4 ft) Height: in vertical orientation was 10.8 m (35.4 ft); height while horizontal was
3 m (10 ft)
Empty Weight: 4,600 kg (10,150 lb) Payload: 450 kg (1000 lb)
Maximum VTOL Weight: 7,460 kg (16,450 lb)