The Me 163 Komet, is still the only rocket powered combat aeroplane to enter combat service. Small, light, an incredible rate of climb, blindingly quick this little fighter set World Speed records that were not surpassed until long after the end of the Second World War.
The Komet was designed by Alexander Lippisch based upon his swept wing glider designs for the DFS, German Glider Institute. It showed it's glider Heritage with a skid landing gear, and 2 wheeled dolly for take off. The intended power plant for the Komet was to be produced by Walter, using two highly volatile liquids.
Initially the Komet was to be built by DFS and Heinkel, but problems with DFS, resulted in Alexander Lippisch losing confidence that they could complete construction, and at his request work was moved to Messerschmitt in 1939. Alongside this Walter were having reliability problems with the rocket motor, the delays allowed them to catch up. In early 1940 the DFS194 prototype was moved to Peenemunde West where it received it's engine. Although still unreliable, the prototype reached a speed of 550 K/h (342 Mph) in one test.
(Me 163A prototype. Photo from Bundesarchiv, Bild 146-1972-058-62 / CC-BY-SA)
Production proceeded on 13 Me 163A prototypes including 8 pre-production models in early 1941. The designation was chosen in an effort to confuse the Allies as it was previously used for a Messerschmitt design for a two seat trainer, that lost out to the Fieseler Storch. After receiving the HWK RII-203 rocket engine. After testing, the Prototype Me163A V4 designation KE+SW achieved a speed of 1,004.5 km/h (624.2 mph) In order to conserve fuel for this flight the Komet was towed to altitude then released and it's engine started.
The famous German test pilot Hanna Reitsch flew the Komet, but in a test flight she released the undercarriage dolly too late. It bounced up striking the underside of the aircraft getting hung up on the landing skid. In spite of this accident, production was scheduled for the aircraft as the Me 163B. The plan was for rings of airfields around German cities of about 40 Km diameter where the plane was to be deployed.
The design was simplified for production with the addition of a windmill generator in the nose and initially armed with two MG151 20mm cannons mounted in the wing roots. These were later changed to Rheinmetall-Borsig Mk 108 30mm cannons. The rocket motor installed was The newly developed HWK 109-509A producing a thrust of 1700 Kg of thrust. The motor had about 9 minutes endurance lifting the plane to to it's combat altitude of 10,000 Meters in approximately 3 minutes. In level flight, the plane would accelerate to 550+ Kph far faster than any contemporary Allied fighter. One Me 163B Komet achieved an unofficial world speed record of 1,130 km/h (702 mph) from a standing start. Although the Bell X1 flew faster this was an air drop from a mothership. The First aircraft to exceed the performance of the Komet from a normal take off was the Hawker Hunter F MkIII flown by Neville Duke on 31 August 1953, at a speed of 1,171 km/h (728 mph).
HWK 109-509B Walter rocket.
Alongside the phenomenal performance there were significant drawbacks related to the design. The endurance of the plane was approximately 9 minutes, this was significantly less than was promised by the engine designers. The endurance only allowed for 2-4 passes to engage a target before the Komet became a glider and had to return to base. The two constituents of the rocket fuel were highly volatile, and the armament consisting of two 30mm cannon, had a relatively slow rate of fire, and short range. In an attempt to improve the endurance of the Me163B, a new motor was developed. The HWK 109-509B, was fitted with a smaller second combustion chamber. This second chamber was mounted below the main combustion chamber. It produced a thrust of 880 Kg to power the Komet in cruise flight. The main engine was reserved for take off and climb. This improved combat endurance by a notable margin. The second major problem was the fuel for the rocket. It comprised two parts C-Stoff and T-Stoff. C-Stoff comprised a mixture of Hydrazine Hydrate and Methanol, it was highly volatile, flammable and toxic. But this was relatively minor hazard compared to T-Stoff. This was very pure Hydrogen Peroxide with an added stabiliser. If this got onto your skin your flesh would ignite spontaneously literally burning the flesh off your bones. It was highly corrosive and sat in two tanks either side of the pilot. When combined the mixture of two fuels exploded in a similar manner to gunpowder in a flame. The fuel lines were made of metal and had a tendency to leak leading to explosions on landing and even when the aircraft was fuelled and standing on the runway waiting for take off. Strict precautions were enforced for refuelling the Komet, including two separate refuelling crews the second not approaching the aircraft until the first had completely vacated the area. The final problem was the armament. The two 30mm cannons had a relatively low muzzle velocity and rate of fire. This combined with the high rate of closure on the target giving only 2 seconds when the aircraft was in firing range made it difficult to score hits. The Germans approached this problem in an innovative way. The Sondergerät 500 Jägerfaust. Two 5 barrelled batteries were mounted on either side of the fuselage replacing the 30 mm cannons. Each barrel fired a single 50mm shell vertically, triggered by a photocell which in turn was triggered by the shadow as the Komet passed below the bomber. To compensate for recoil the barrel was ejected downwards as the weapon fired.
(The Me163B with commentary by Test Pilot Rudi Opitz.)
The plane was described by Eric 'Winkle' Brown as "Riding a runaway train" during take off and climb, with excellent maneuverability and stability. In combat, Allied pilots soon learned to wait until the Komet's fuel was exhausted before attacking, although this was a difficult proposition due to it's small size and agility. Attacking the airfields was also to be avoided as they were ringed with dense thickets of anti-aircraft artillery.
As a weapon system the Komet proved ineffective, accounting for 16 bombers and losing 9 planes, although only 3 as a result of Allied fighters. Entering service too late, coupled with fuel shortages, particularly of C-Stoff, which was also the fuel for the V1 flying bomb. With insufficient numbers to effectively counter the bombers overflying Germany at will the Komet is regarded as a failure and a desperate gamble by a defeated Germany. It is interesting to speculate though as to what might have happened if this 'Point Defence Interceptor' had entered service in significant numbers a year earlier. Entering combat alongside the Me262 in 1943 they would have made a formidable partnership unmatched by anything in the Allies arsenal.