Messerschmitt Me 163 | |
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Me 163 B-1a at the Museum of Flight | |
Role | Interceptor |
Manufacturer | Messerschmitt |
Designed by | Alexander Lippisch |
First flight | Me 163 A V4 in 1 September 1941 |
Introduction | 1944 |
Primary user | Luftwaffe |
The Messerschmitt Me 163 Komet, designed by Alexander Martin Lippisch, was a German rocket-powered fighter aircraft. It was the only operational rocket-powered fighter aircraft during the Second World War. Although revolutionary and capable of performance unrivaled at the time, it proved ineffective as a fighter and resulted in the destruction of very few Allied aircraft.
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Work on the design started under the aegis of the Deutsche Forschungsanstalt für Segelflug (DFS) — the German Institute for the Study of sailplane flight. Their first design was a conversion of the earlier Lippisch Delta IV known as the DFS 39 and used purely as a glider testbed of the airframe.
A larger follow-on version with a small propeller engine started as the DFS 194. This version used wingtip-mounted rudders, which Lippisch felt would cause problems at high speed, and he later redesigned them to be mounted on a conventional vertical stabilizer at the rear of the aircraft. The design included a number of features from its glider heritage, notably a skid used for landings, which could be retracted into the aircraft's keel in flight. For takeoff, a pair of wheels, each mounted onto the ends of a specially designed cross-axle, together comprising a takeoff "dolly" mounted under the landing skid, were needed due to the weight of the fuel, but these were released shortly after takeoff. It was planned to move to the Walter R-1-203 cold engine of 400 kg (882 lbf) thrust when available.
Heinkel had also been working with Walter on his rocket engines, mounting them in the He 112 for testing, and later the first purpose-designed rocket aircraft, the He 176. Heinkel had also been selected to produce the fuselage for the DFS 194 when it entered production, as it was felt that the highly volatile fuel would be too dangerous in a wooden fuselage, with which it could react. Work continued under the code name Project X.
However the division of work between DFS and Heinkel led to problems, notably that DFS seemed incapable of building even a prototype fuselage. Lippisch eventually requested to leave DFS and join Messerschmitt instead. On 2 January 1939 he moved along with his team and the partially completed DFS 194 to the Messerschmitt works at Augsburg.
The delays caused by this move allowed the engine development to "catch up", and once at Messerschmitt the decision was made to skip over the propeller-powered version and move directly to rocket power. The airframe was completed in Augsburg and shipped to Peenemünde West in early 1940 to receive its engine. Although the engine proved to be extremely unreliable, the aircraft had excellent performance, reaching a speed of 342 mph (550 km/h) in one test.
Production of a prototype series started in early 1941, known as the Me 163. Secrecy was such that the number, 163, was actually that of the earlier Messerschmitt Bf 163 project to produce a small two-passenger light plane, which had competed against the Fieseler Fi 156 Storch for a production contract, as it was thought that intelligence services would conclude any reference to the number would be for that earlier design. Me 163 A V4 was shipped to Peenemünde to receive the HWK RII-203 engine on May 1941, and on 2 October 1941, the Me 163 A V4, bearing the radio call sign letters, or Stammkennzeichen, "KE+SW", set a new world speed record of 1,004.5 km/h (623.8 mph), piloted by Heini Dittmar[1][2]. This would not be officially approached until the postwar period by the new jet fighters of the British and U.S., and was not surpassed until the American Douglas Skystreak turbojet-powered research aircraft did so on 20 August 1947. Five prototype Me 163 Anton A-series experimental V-aircraft were built, adding to the original DFS 194 (V1)[3], followed by eight pre-production examples designated Me 163 A-0.
During testing the jettisonable main landing gear arrangement proved to be a serious problem and caused many aircraft to be damaged at takeoff when the wheels rebounded and crashed into the aircraft. Malfunctioning hydraulic dampers in the skid could lead to back injuries for the pilot on landing, as the aircraft lacked steering or braking control during the landing run, leaving the pilot unable to avoid obstacles. Once on the ground, it had to be retrieved by an adapted tractor-like vehicle originally meant for agricultural use on small farms, the three-wheeled Scheuch-Schlepper[4] , as the Komet was unpowered and lacked wheels at this point.
During flight testing, the superior gliding capability of the swept-wing Komet proved detrimental to safe landing. The aircraft would rise back into the air with the slightest updraft. Since the approach was made unpowered, there was no opportunity to make another landing pass if the aircraft failed to stop at the proper airfield. For production models, a set of landing flaps allowed somewhat more controlled landings. This issue remained a problem throughout the program, however.
Nevertheless the performance was tremendous and plans were made to put Me 163 squadrons all over Germany in 25 mile (40 km) rings. Development of an operational version was given the highest priority.
Meanwhile Walter had started work on the newer HWK 109-509 hot engine, which added a true fuel of hydrazine hydrate and methanol, designated C-Stoff, that burned with the oxygen-rich exhaust from the T-Stoff, used as the oxidizer, for added thrust. (See List of Stoffs.) This resulted in the significantly modified Me 163 B of late 1941. Due to the RLM requirement that it should be possible to throttle the engine, the originally simple power plant grew complicated and lost reliability. The new fuel proved an unfortunate choice as well, since hydrazine hydrate was also used in the launcher of the V-1 "Doodlebug" flying bomb and was in short supply throughout the 1943-45 period.
The fuel system was particularly troublesome, as leaks experienced during hard landings easily degenerated in fires and explosions. Metal fuel lines and fittings, which failed in unpredictable ways, were used as this was the best technology available. Both fuel and oxidizer were toxic and required extreme care when loading in the airframe -- yet there were still occasions when Komets simply exploded on the tarmac. The corrosive nature of the liquids also mandated special protective gear for the pilots.
Two prototypes were followed by 30 Me 163B-0 aircraft armed with two MG 151/20 cannon and some four hundred Me 163B-1s armed with two MK 108 cannon, but which were otherwise similar to the B-0. Occasional references to B-1a or Ba-1 subtypes are found in the literature on the aircraft, but the meanings of these designations are somewhat unclear. Early in the war, when German aircraft firms created versions of their aircraft for export purposes, the a was added to export (ausland) variants (B-1a) or to foreign-built variants (Ba-1) but for the Me 163, there were neither export nor a foreign-built version. Later in the war the a, and successive letters, were used for aircraft using different engine types (Me 262 A-1a with Jumo engines, A-1b with BMW engines). As the Me 163 was planned with an alternative BMW P3330A rocket engine it's quite safe to assume the a was used for this purpose on early examples. Only one Me 163, the V10, was tested with the BMW engine so this designation suffix was soon dropped. The Me 163 B-1a didn't have any wingtip "washout" built into it, and as a result had a much higher critical Mach number than the Me 163 B-1. [5]
The Me 163B had very docile landing characteristics, mostly due to its integrated leading edge slots, located directly forward, along the wing's leading edge, of the elevon control surfaces. It was found to be impossible to stall, nor would it spin. One could fly the Komet with the stick full back and have it in a turn and then use the rudder to take it out of the turn and not fear it snapping into a spin. It would also slip beautifully. Because it was derived from a glider it had excellent gliding qualities which meant it had the tendency to keep on flying above the ground. On the other hand, making a too close turn from base onto final, the sink rate would increase, and one could quickly lose altitude and come in short. Another main difference from a propeller-driven aircraft is that there was no slipstream over the rudder. On takeoff one had to attain the speed at which the aerodynamic controls become effective — about 80 mph (130 km/h) — and that was always a critical thing. One had to be careful the control stick wasn't somewhere in the corner when the control surfaces began working. These, like many other specific Me 163 problems, would be resolved by specific training.
The performance of the Me 163 far exceeded that of contemporary piston engine fighters. At a speed of over 200 mph (320 km/h) the aircraft would take off, in a so-called "sharp start" from the ground, from its two-wheeled dolly. The aircraft would be kept at low altitude until the best climbing speed of around 420 mph (680 km/h) was reached, at which point it would jettison the dolly, pull up into a 70° angle of climb, and rapidly climb to the bombers' altitude. It could go even higher if need be, reaching 40,000 ft (12,000 m) in an unheard-of three minutes. Once there, it would level off and quickly accelerate to speeds around 550 mph (880 km/h) or faster, which no Allied fighter could hope to match. Because of its thin wings it didn't suffer from compressibility or other aerodynamic problems as much as other early jet aircraft. What's more, the aircraft was remarkably agile and docile to fly at high speed. According to Rudolf Opitz, chief test pilot of the Me 163, it could "fly circles around any other fighter of its time".
By this point Messerschmitt was completely overloaded with production of the Bf 109 and attempts to bring the Me 210 into service. Production in a dispersed network was handed over to Klemm, but quality control problems were such that the work was later given to Junkers, who was at that time underworked. As with many German designs of World War II, parts of the airframe (esp. wings) were made of wood, which allowed furniture manufacturers to act as subcontractors.
For training purposes the older Me 163A and first Me 163B prototypes were used. But it was planned to introduce the Me 163 S, which removed the rocket engine and tank capacity and placed a second seat for the instructor behind the pilot. The 163 S would be used for glider landing training, which as explained above, was essential to operate the Me 163. It appears the 163 Ss were converted from the earlier Me 163B series prototypes.
In service the Me 163 turned out to be difficult to use against enemy aircraft. Its tremendous speed and climb rate meant a target was reached and passed in a matter of seconds. Although the Me 163 was a stable gun platform it required excellent marksmanship to bring down an enemy bomber. The Komet was equipped with two MK 108 30 mm cannons which had a relatively low muzzle velocity, with the characteristic ballistic drop of such a weapon, which meant they were only accurate at short distance, and that it was almost impossible to hit a slow-moving bomber when the Komet was traveling very fast (three hits were typically needed to take down a B-17).
A number of innovative solutions were implemented to ensure kills by less experienced pilots, the most promising was a unique weapon called the Sondergerät 500 Jägerfaust. This consisted of a series of single-shot, short-barreled 50 mm guns pointing upwards. Five were mounted in the wing roots on each side of the aircraft. The trigger was tied to a photocell in the upper surface of the aircraft, and when the Komet flew under the bomber, the resulting change in brightness caused by the underside of the aircraft could cause the rounds to be fired. As each shell shot upwards, the disposable gun barrel that fired it was ejected downwards, thus making the weapon recoilless. It appears that this weapon was used in combat only once, resulting in the destruction of a Halifax bomber,[6] though other sources say it was a Boeing B-17[7][8]
The biggest concern about the design was the short flight time, which never met the projections made by Walter. With only seven and a half minutes of powered flight, the fighter truly was a dedicated point defense interceptor. In order to improve on this, work started on the development of an engine with two separate combustion chambers of differing sizes, oriented one above the other, with the upper one (of the larger size) tuned for "high power" for takeoff and climb, and the smaller volume, lower chamber with approximately 400 kg (880 lb) of thrust at its top performance level, for efficient lower-power cruise. This HWK 109-509 C would improve endurance by as much as 50%. Two 163 Bs, V6 and V18, were experimentally fitted with the new engine and tested in 1944. On 6 July 1944, the Me 163 B V18 (VA+SP) set a new world speed record of 1,130 km/h (702 mph), piloted by Heini Dittmar, and landed with almost all of the vertical rudder surface broken away from flutter. [9] [1] This record was not broken in terms of absolute speed until November 6, 1947 by Chuck Yeager in a flight that was part of the of the Bell X-1 test program, with an 891 mph (1434 km/h) speed, recorded at an altitude of nearly 49,000 ft (14.82 km) altitude.[2]. But the X-1 never exceed this speed in a normal runway liftoff, Heini Dittmar reached this 1130 km/h performance, after a normal "sharp start" ground takeoff, without an air drop from a mother ship. Neville Duke exceed Heini Dittmars record mark in 31 August 1953 with the Hawker Hunter F Mk3 with a speed of 1171 km/h, after a normal ground start.[10] Aircraft of the configuration the Me 163 used were eventually found to have serious stability problems when entering transonic flight, like the similarly configured, and turbojet powered, Northrop X-4 Bantam and de Havilland DH 108, which made the V18's record with the Walter 509C "cruiser" rocket more remarkable.
Woldemar Voigt of Messerschmitt's Oberammergau offices started a redesign of the 163 to incorporate the new engine, as well as fix other problems. The resulting Me 163 C design featured a larger wing through the addition of an insert at the wing root, an extended fuselage with extra tank capacity through the addition of a "plug" insert behind the wing, and a new pressurized cockpit topped with a bubble canopy giving dramatically improved visibility. The additional tank capacity and cockpit pressurization allowed the maximum altitude to increase to 52,000 ft (16,000 m), as well as improving powered time to about twelve minutes, almost doubling combat time (from about five minutes to nine). Three Me 163C-1a prototypes were planned, but it appears only one was flown, and that without its intended engine.[11]
But by this time the project was moved to Junkers. Here a new design effort under the direction of Heinrich Hertel at Dessau attempted to improve the Komet. The Hertel team had to compete with the Lippisch team and their Me 163C. Hertel investigated the Me 163 and found it was not well suited for mass production and not optimized as a fighter aircraft, with the most glaring defeciency being the lack of a retractable landing gear of any sort. For this the Me 163V-18 was equipped with a non-retractable tricycle landing gear. (This prototype is often called the Me 163D but it is now clear that there never was a 163 D.) The resulting Junkers Ju 248 used a three-section fuselage to ease construction. The V1 prototype was completed for testing in August 1944, and was glider tested behind a Junkers Ju 188. Some sources state that the Walter 109-509 C engine was fitted in September, but it was probably never tested under this power. At this point the RLM re-assigned the project to Messerschmitt, where it became the Me 263. This appears to have been a formality only, with Junkers continuing the work and planning production[12].
However, by the time the design was ready to go into production, after many delays, the plant it was to be made at was overrun by Soviet forces. While it did not reach operational status, the work was briefly continued by the Russian Mikoyan-Gurevich (MiG) design bureau as the Mikoyan-Gurevich I-270[13].
Operations began in 1944. As expected, the aircraft was extremely fast, and for a time the Allied fighters were at a complete loss as what to do about it. Singly or in pairs, the Komets attacked, often faster than the opposing fighters could dive in an attempt to intercept them. A typical Me 163 tactic was to zoom through the bomber formations at 30,000 ft (9,000 m), up to an altitude of 35,000–40,000 ft (10,700–12,000 m), then dive through the formation again. This approach afforded the pilot two brief chances to fire a few rounds from his cannons before gliding back to his airfield. The pilots reported that it was possible to make four passes on a bomber, but only if it was flying alone.[14]
As the cockpit was unpressurized, the operational ceiling was limited by what the pilot could endure for several minutes while breathing oxygen from a mask, without losing consciousness. Pilots underwent altitude chamber training to harden them against the rigors of operating in the thin air of the stratosphere without a pressure suit. Special low-fiber diets also had to be prepared for pilots as any gas in the gastrointestinal tract would expand rapidly as the aircraft rocketed toward the high-flying bomber formations.
One fighter wing, Jagdgeschwader 400 (J.G. 400 also JG 400), commanded by Major Wolfgang Späte, was equipped with the craft in two groups, with the mission of defending synthetic gasoline installations during May 1944. First actions occurred at the end of July, attacking two USAAF B-17 Flying Fortress bombers without confirmed kills and continuing in combat from May 1944 to spring 1945. During this time, there were nine confirmed kills with 14 lost. Feldwebel Siegfried Schubert was the most successful pilot with three four-engine-bombers to his credit.[15]
Allied fighter pilots quickly noted the short lifetime of the powered flight. They would wait it out, and as soon as the engine went dead they would pounce on the unpowered, gliding Komet. The Komet was however extremely manoeuvrable and could pull out of a turn much later than any Allied fighter. Another Allied method was to attack the fields the rocket fighters operated from and started strafing them after the Me 163s landed[16]. Setting up a defensive perimeter with anti-aircraft guns quickly meant that Allied fighters stayed clear of these bases. At the end of 1944, 91 aircraft had been delivered to JG 400 but a continuous lack of fuel had kept most of them grounded. It was clear that the original plan for a huge network of Me 163 bases was never going to happen. Up to that point, JG 400 had lost merely six aircraft due to the enemy actions. Nine were lost to other causes, remarkably low for such a revolutionary and technically advanced aircraft. In those last days of the Third Reich the Me 163 was given up in favour of the more successful and threatening Me 262. In May 1945, Me 163 operations were stopped, the JG 400 disbanded, and many of their pilots sent to fly Me 262s.[14]
In any operational sense the Komet was a failure. Even though they shot down 16 aircraft, and mainly expensive four-engined bombers, it did not warrant the efforts put into the project. With the projected Me 263 things could have turned out differently. But in the end, the Komet never was an effective fighter aircraft. Due to fuel shortages late in the war, very few actually went into combat, and it took an experienced pilot with excellent shooting skills to achieve "kills" with the Me 163. In order to recify this problem, one Me 163 was tested using a vertically-firing SG 500 Jagdfaust, a thin-walled high-explosive rocket-propelled shell, which was fired by means of a light-sensitive cell activated by the shadow of a bomber. Flying his Me 163 underneath a B-17 bomber Leutnant Fritz Kelb destroyed the bomber. A dozen Me 163's were modified this way, but they came too late to join combat.
Furthermore, due to the volatile nature of its rocket fuel, flying the Me 163 proved to be more dangerous to the pilots than to the enemy. Not counting aircraft built specifically for Kamikaze attacks, the Me 163 thus remains the war plane most deadly to its pilots. But at the same time the Komet was a remarkable design that pointed the way to the future. It was one more piece of strong evidence that the day of the propeller fighter was over, and it also spawned later weapons like the Bachem Ba 349 Natter and Convair XF-92. Ultimately, the point defense role that the Me 163 played would be taken over by the surface-to-air missile (SAM), Messerschmitt's own example being the Enzian. The airframe designer, Alexander Martin Lippisch went on to design delta-winged supersonic aircraft for the Convair Corporation.
It has been claimed that at least 29 "Komets" were shipped out of Germany after the war and that of those at least 10 have been known to survive the war[17] to be put on display in museums around the world. Most of the 10 surviving Me 163s were part of the special Luftwaffe rocket fighter wing known as Jagdgeschwader 400 (JG400), and were captured by the British at Husum, the squadron's base at the time of Germany's surrender in 1945.
Of the 21 aircraft that were captured by the British at least three have survived until today. The were assigned the British serial numbers AM200 until AM220.[19]
Like two of the British Komets, this aircraft was part of JG 400 and captured at Husum. It was shipped to Canada in 1946.
Werknummer 19116 (but more probable 191916) and 191095 (AM211) also seem to have been held at one time in this museum.[20][21]
This aircraft was also part of JG 400 and captured at Husum.
As part of their alliance, Germany provided the Japanese Empire with plans and an example of the Me 163[22]. One of the two submarines carrying Me 163 parts did not arrive in Japan, so at the time the Japanese lacked a few important parts, including the turbopump which they could not make themselves. The Japanese Me 163 crashed on its first flight and was completely destroyed.[23] The Japanese versions were designed as trainers, fighters, and interceptors. Differences between the versions were fairly minor. The Mitsubishi Ki-200 Shusui ("Shu" means "autumn", "sui" means "water" in Japanese) was the equivalent of the 163 B, armed with two 30 mm Ho 155-II cannon. The Navy version, the Mitsubishi J8M1 Shusui, simply replaced the Ho 155 cannon with the Navy's 30 mm Type 5.
Mitsubishi also planned on producing a version of the 163 C for the Navy, known as the J8M2 Shusui Model 21. A version of the 163 D/263 was known as the J8M3 Shusui for the Navy with the Type 5 cannon, and Ki-202 Shusui-kai ("kai" means "modified" in Japanese) with the Ho 155-II for the Army.
Trainers were planned, roughly the equivalent of the Me 163 A-0/S. These were known as the Yokoi Ku-13 Akigusa ("Aki" means also "autumn" and "gusa (kusa)" means "grass" in Japanese) or Ki-200 Syusui Rocket Interceptor practice glider.
Other trainer variants included:
A flying replica Me 163 was constructed between 1994 and 1996 by Joseph Kurtz, a former Luftwaffe pilot who trained to fly Me 163's but who never flew in combat. He subsequently sold the aircraft to EADS. The replica is an unpowered glider whose shape closely matches that of an Me 163, although its weight and internal construction differ considerably. Reportedly, it has excellent flying characteristics.
XCOR Aerospace, an aerospace and rocketry company, proposed a rocket powered replica. Although outwardly the same as a wartime aircraft, the design would have differed considerably for safety reasons. It would have been powered by a simpler and safer, pressure fed, liquid oxygen/alcohol engine and retractable undercarriage would have been used instead of a take-off trolley and landing skid. The project is no longer discussed on the company's website and it appears work has ceased on this project, possibly due to lack of commercial interest.
Several static replica aircraft are exhibited in museums.
General characteristics
Performance
Armament
Related development
Comparable aircraft
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