Messerschmitt Me 163 [Interceptor]
The Messerschmitt Me 163 Komet (comet) rocket interceptor stemmed from prolonged research by Dr Alex-ander Lippisch over 15 years before the war. The heart of Projekt X was a rocket engine developed by Hellmuth Walter. Lippisch's task was to design a tailless aircraft to go with it. Even he was not allowed to have blueprints of the power-plant for the airframe he was designing. The result of this clandestine effort was a tailless rocket research craft designated the DFS 194 which began flight trials with a 400-kg (882-lb) thrust liquid-fuel Walter rocket motor at the Baltic coast test site of Peenernfinde in August 1940. While test pilot Heini Dittmar flew this test bed, reaching 550 kph (341.8 mph) in level flight, Lippisch and his team pressed on with the next stage of Projekt X at the Messerschmitt Werke in Augsburg. The ultimate aim was to produce a rocket-powered interceptor fighter.
In the mid 1930s the German Air Ministry were supporting the work of rocket engine designer Hellmuth Walter, issuing him a contract to develop a 400 kg / 882 lb thrust motor. In the mean time, Alexanderander Lippisch had been working at the German Institute for the Study of Sailplane Flight (DFS) and was given the order to produce a second prototype of his DFS 39 tail-less aircraft to test the potential of a rocket powered airframe. The work would see DFS build the wings and Heinkel build the fuselage.
Lippisch discovered the wing mounted rudders would likely cause unacceptable flutter, so he redesigned the airframe to include a large conventional central fin and rudder. Redesignated DFS 194 it was fitted with a small propeller engine and a landing skid. A takeoff dolly was mounted under the landing skid, it being jettisoned shortly after takeoff.
Dr Lippisch and his staff were transferred to Messerschmitt's works at Augsburg in January 1939, with the partially completed DFS 194. The decision was also made to by-pass the prop driven version and move directly to rocket power.
The completed airframe was shipped to Peenemünde West in early 1940.
The Comet’s wooden, plywood-covered wings are of special swept-back design with a marked wash-out of incidence towards the tip. The fuselage is of metal construction. “Elevons” which serve both as elevators and ailerons are located outboard in the wings; there are no horizontal tail surfaces.
Three development prototypes of the DFS 194 were ordered by the RLM and the first two were completed by the spring of 1941, when un-powered gliding flights began from the factory airfield. The engineless Messerschmitt Me 163 attained a top speed of 850 kph (528 mph) in a dive test.
In early 1940 the DFS 194 was equipped with a rocket motor at Peenemünde. After test flights by Heini Dittmar had confirmed speeds of up to 550km/h on the power of a single 2.94kN Walter motor, there was sufficient interest to initiate development. In 1941 the first Me 163 prototype was being tested in gliding flight and shortly after was fitted with a 7.35kN Walter RII-203 rocket motor. On 2 October 1941 Heini Dittmar cast off from a Messerschmitt Bf 110 tow-plane at 4000 m (13,125 ft), fired the Me 163V-1's rocket motor and accelerated rapidly reached 1004.5 kph (623.8mph); two months later the Me163B Komet was ordered into production.
Speeds of up to 915km/h were achieved (limited by the volume of liquid propellants carried) and to gain some idea of the speed potential, this aircraft was towed to a high altitude before being released. Flown under power, a speed of over 1,000km/h was attained before the engine had to be throttled back because the aircraft was becoming uncontrollable.
This success saw the development of the first production prototype, now designated Me 163. Flight testing began in the Spring of 1941. These were a series of unpowered flights before the Me 163 V1 was shipped to Peenemünde for installation of the improved Walter RII-203 engine.
On 2 October 1941, the Me 163 V1 piloted by Heini Dittmar set a new world speed record of 1004.5 kph / 623.8 mph. After this performance, the RLM instructed Lippisch to design an improved version around a more powerful motor under development. The resulted in the Me 163B. The first prototype, the Me 163 V3, was completed in April 1942, but it was not until early autumn that the first Walter 109-509A motors were ready for installation.
Plans proceeded during 1943 to equip the first operational units with the Me 163B-1a. Production Me 163Bs were po-wered by Walter 109-509A2 rocket motors using T-Stoff (hydrogen peroxide) and C-Stoff (hydrazine hydrate, methyl alcohol and water) to give a thrust of 1700 kg (3,748 lb).
The new motor employed a ‘hot’ system in which the oxygen was ignited for additional thrust and better fuel efficiency. Flight testing of the first series of Me 163B-0 pre-production aircraft proceeded throughout 1942.
The fuselage of the Komet was made of metal but its wing was of wooden construction. The leading edge of the wing featured long slats in front of the elevons. Early Me 163B-0 aircraft were armed with a pair of 20-mm guns, but Me 163B-1 fighters carried two 30-mm weapons. The air-craft possessed no conventional land-ing gear, but took off from a trolley, which was jettisoned immediately af-ter take-off and at the end of the flight the Komet was landed on the skid. The small propeller on the nose served to drive a generator which supplied electrical power for the radio and instruments. Armour includes a nose cone constructed of 15-mm plate. Laminated bullet-resisting glass gives the pilot added protection from frontal attack. Two triangular plates comprise the side cock-pit armor. No provision is made for defense against attack from the rear except the plane’s high speed.
The production Me 163B's 1500-kg (3307-1b) thrust Walter HWK 109--509 rocket motor was fuelled with a highly volatile mixture of C-stoff (methyl alcohol, hydrazine hydrate and water) and T-stoff (hydrogen peroxide with additional hydro-carbon stabilizers) which would explode at the least provocation. The Komet carried more than 2000 kg (4409 lb) of fuel and climbed to 12,000 m (39,370 ft) in 3 minutes 30 seconds. The Walter HWK 109-509A rocket motor made use of a steam generator that used calcium permanganate as a catalyst to produce steam when a small amount of T-Stoff was added via an electric starter motor, the resulting steam starting the turbine to begin pumping the two fuels to the rocket motor. The starter motor was switched off, and the rocket motor was throttled through its five positions until it reached maximum thrust.
Messerschmitt Me 163 B-1 Komet
After rocketing high, the Komet pilots would use their remaining fuel to dive at high speed through the ranks of bombers firing on them with the Me 163B’s two 20mm MG 151/120 or 30-mm MK 108 cannon, or with the SG 500 Yagdfaust (hunter's fist) 50-mm (1.97-in) weapon system, which fired shells vertically upwards from the top surface of the Komet's wing when a bomber's shadow triggered its photo-electric cell firing circuit.
Series production began at dispersed facilities by Klemm, but was later transferred to Junkers, as a result of quality control problems. An operational training unit, Erprobungskommando 16 (EK 16) was formed during July 1943 at Peenemünde West, but moved to Bad Zwischenahn before the first group of pilot trainees arrived. The unit received its first group of 36 pilot trainees in the summer of 1943 and by May 1944 the first operational Me 163 wing, Jagdgeschwader 400 (JG 400) was created under the command of Hauptmann Wolfgang Späte. The unit was ordered to defend the synthetic oil refineries at Leuna from its base at Brandis, near Merseburg.
Two additional units fighter groups, II and III/JG 400 were formed before the end of the war, but only saw limited combat against single aircraft.
JG 400 made interceptions of Allied bombers on 7th and 28th of July 1944, without success, but on 16 August Fw Siegfried Schubert scored the types first success. He scored three victories before his death in that October. The only other major USAAF interceptions were on 24 August (4 B-17s shot down by 1 Gruppe), 11th September, and 2nd November.
Although the aircraft’s two 30mm MK 108 cannons were capable of downing a four engined bomber with only a few hits, the Komet’s high speed, and the cannons’ slow rate of fire and short range, made effective gunnery nearly impossible. As a result, the Me 163 pilots recorded a total of only nine confirmed kills. (Schubert 3 kills, Kelb, Schiebeler, Ryll, Strasnicky, Glogner, & Bott one each). After completing an attack, the pilot had to glide back to base as the fighter only carried enough fuel for eight minutes of powered flight.
In response to combat reports, alternative weapons were including the SG 500 recoilless ‘Jägerfaust’. Five were mounted in either wing and fired by photocell trigger as the aircraft passed below.
Further combat sorties were curtailed by order by the end of 1944 due to pilot losses as high as 30%. On 14 April 1945, the remaining aircraft at Brandis were destroyed and the remaining personnel ordered to join the army. The official order to disband 1./ and II./JG 400 was issued on 20 April 1945.
An improved variant with greater endurance and a tricycle undercarriage, the Me 163 C was also produced in small numbers, but was not flown operationally. A few examples of a two seat trainer, the Me 163 S were also completed. The slightly larger Me 163C development - with aerodynamic refinements, pressurised cockpit and blister-type canopy, and more powerful Walter 109-509C rocket motor and auxiliary cruising jet - was built only in prototype and pre-production form. It did not enter service, although it was almost ready for delivery to Luftwaffe squadrons at the time of the German surrender. With this version, endurance was increased from eight-ten minutes to twelve minutes of powered flight. It was faster by 40 mph, weighing 11,280 pounds.
The Me 163D was developed in to the Me 263. The aircraft was briefly known as the Junkers Ju 248 V1.
Produced in only small numbers, about 360 examples were completed.
Official top speed of the Comet, contrary to Messerschmitt’s statement, is 550 mph at 20,000 feet and above. Armament consists of two 30-mm cannon, one in each wing root, firing a total of 120 rounds. Normal flying weight of the 163 is 9,500 pounds; wing span is just over 30 feet, length, slightly under 20.
The fuels in the Komet were highly corrosive and would dissolve organic material (such as the pilot). To avoid this, the pilots would wear special asbestos fibre suits. A bumpy landing sometimes caused unburned fuels to mix and ignite.
Me 163B Komet
Wing span: 30 ft 7 in (9.32 m)
Length: 18 ft 8 in (5.69 m)
Engines: 1 x Walter, 3300 lb
Max TO wt: 9042 lb (4110 kg)
Max level speed: 596 mph ( 960 kph)
Powerplant; 1 Walter HWK 509A-1 (or A-2), 3,748lb (1700kg) thrust
Fuel; C-stoff: 57% methyl alcohol, 30% hydrazine hydrate, 13% water - T-stoff: 80% hydrogen peroxide, 20% stabilisers
Max. speed: 559mph sea level to 39,400ft (12,000m)
Service Ceiling; 39,400ft (12,000m)
Climb: 1.48 minutes to 6,600ft (2,000m)
Climb: 2.02 minutes to 13,100ft (4,000m)
Climb: 2.27 minutes to 19,700ft (6,000m)
Climb: 3.45 minutes to 39,400ft (1 2,000m)
Endurance; 7min 30sec
Range; Approx 80 miles (130km)
Empty weight: 4,1901b (1900kg)
Max takeoff weight: 9,0521b (4310kg)
Wing span: 30ft 7in (9.40m)
Length: 19ft 2in (5.85m)
Height: 9ft (2.75m) on takeoff dolly
Wing area: 199.1 square feet (18.5sq.m)
Armament Two 30mm Rheinmetall - Borsig MK 108 cannon / 60 rpg
Messerschmitt Me-163 Komet