Saturday, 26 September 2015

Messerschmitt Me 163 Komet. Part 1: The beginning of history. The armament and Power plant. Compiler Luis German Dzib Aguilar





T
he Messerschmitt Me 163 Komet, designed by Alexander Lippisch, was a German rocket powered fighter aircraft. It is the only rocket-powered fighter aircraft ever to have been operational. Its design was revolutionary, and the Me 163 was capable of performance unrivaled at the time. German test pilot Heini Dittmar in early July 1944 reached 1,130 km/h (700 mph),  aflight airspeed record. Over 300 aircraft were built, but the Komet proved ineffective as a fighter and was responsible for the destruction of only about nine Allied aircraft. (1) (16 air victories for 10 losses, according to other sources.) (2)

The Me-163 Komet was conceived by Dr. Alexander Lippisch but production & later development was carried out by Messerschmitt. The aircraft was powered by one of the new generation of rocket engines. To reduce weight & drag the Me-163 had no tail or undercarriage. Taking off on a trolley that was later jettisoned & landing on a wooden skid, the first test flight took place in 1941 & after considerable development became operational in 1944. None the less the aircraft had it's dangers. The volatile fuel could dissolve the flesh of pilots & ground crew in a matter of seconds. The pilot's flight suit, boots, underwear and gloves are made of a non-organic, nylon-like material. Clothing made of organic material like cotton would burst into flames on contact with the fuel. The pilot was protected by 13mm of armour behind his head and shoulders, and 8mm of armour behind his back. A 90mm armour glass screen gave frontal protection with a 15mm armour nose cone. The constant speed propeller in front drove a generator for electric power.
The high speed of 596 mph (959 km/h) made it difficult to control & it's short endurance of just under an hour limited it's effectiveness. The Me-163's inherent dangers led to more aircraft being lost in accidents than were destroyed in combat.
The Me-163 Story (3)
The story started in 1926 when Dr Alexander Lippisch built his first tailless glider. Over the next decade Lippisch built many tailless aircraft and also became involved with rocket propulsion, so it was no great surprise when, in 1937, he was asked by the research section of RLM to design an aircraft to test a new rocket motor intended for manned aeroplanes, the Walter I - 203.
In 1939 Lippish decided that his preliminary research aircraft, the all-wood DFS-194,could in fact be flown by the rocket and not by the intended small piston engine. The machine was taken in early 1940 to Karlshagen, the test airfield at Peenemünde, where the I-230 rocket was installed. On June 3, 1940 glider pilot Heini Dittmar made a successful first flight, reporting superb handling. Later this flimsy machine, designed for 300 km/h (186.5 mph), reached 547 km/h (340 mph) in level flight, and also demonstrated fantastic steep climbs.

On 2nd October, 1941 Dittmar was towed to over 4000 m (13,124 ft) by a Bf-110; he then cast off and started the motor. He accelerated but suddenly lost control as the nose dropped violently. It was possibly the first occasion on which a human had approached the speed of sound, compressibility trouble being experienced at about Mach 0.84 the speed of 1000.4 km/h (622mph ) was 250 km/h (155.3 mph) above the official world speed record.
By 22nd October, 1941, Messerschmitt A.G. gave Udet a detailed plan for the construction of 70 Me-163B interceptors that could lead to an operational fighter group by the spring of 1943. The eight 163A's already built would serve as trainers.
In November, Dittmar severely injured his back on landing a 163 and was confined to the hospital. Test pilot Rudy Opitz assumed leadership of the project. By June 1943, the new “hot” engine had been delivered, but the run time was a disappointing 6 minutes.
Me-163B made first flight at Lechfeld on 26th June 1942 without propellants and towed by a Bf-110. Next year powered flights began. In early 1943 a special Me-163B test squadron was formed at Kartshagen under Hauptmann Wolfgang Späte. The Unit was named Erprobungskommando 16 and it later moved to Bad Zwischenahn. On 17th August, 1943 the factory at Regensburg was heavily hit by B-17's resulting in many pre-production batches being destroyed.
The unit I/JG400 under Oberleutnant Robert Olejnik formed from Erprobungskommando 16 at Zwischenahn in May 1944 became operational in July, at Brandis. There were several flights against USAF heavies but without success. But on 24th August Feldwebel Siegfried Schubert destroyed two American B-17 Flying Fortresses within five minutes and other Comets downed two others. Schubert was the most successful of all Komet pilots in combat.
Aerial Combat in the Me-163
The 163 was originally envisioned as an interceptor for high flying reconnaissance aircraft but it was instead used to attack large formations of bombers. Maybe two or three would take off in a cluster or singly and have five minutes to attack the bombers. Now you can imagine a fighter pilot with little experience would want to fly a standard approach from the back, maybe out of a 15-degree turn and attack a B-17 bristling with that massive defensive power. That became a pretty risky thing. And approaching bombers one aircraft at a time, using that standard school-training approach, would mean your chances of surviving many missions was low.
“The highly experienced fighter pilots could fly and attack in a 45-degree climb. They were quite safe because the turrets on the bombers could not easily follow them. These were the pilots who survived.
The Komet's 600 mph (959 km/h ) speed stunned the allied bomber crews who saw it for the first time. It was a weapon of moral sapping capability when they first appeared against daylight streams of allied bombers.There was a real feeling amongst the allies that here was a weapon they couldn't intercept or contend with. With cannons or rockets firing the Komet would streak through allied bomber formations often breaking them up in the process. It would then glide down to its airstrip re-fuel & take off to attack again.
Its appearance was so unexpected it shook the confidence of the men who confronted it. The bomber crews hadn't been warned about the rocket powered plane because the allies knew almost knothing about it.
When the 163 was designed, Germany had air superiority at the lower altitudes. That was not the case anymore in 1944. There were P-51's and P-38's, and their pilots learned very fast that as the 163's came up, you left them alone, but on the way down the 163's had a short flying time, and they could be targeted. But the 163, now empty of fuel, had a low wing loading and could dive much closer to the ground before pulling out than could the Allied fighters.
Whereas the experienced 163 pilot would come down at 500 mph (805 km/h), down to the deck and come over a friendly airfield, fly inside the defense perimeter and stay there circling until it bled off it's speed and landed, the Allied fighters had a long way to fly home, and were not going to risk flying within that perimeter. But there were very few people who could fly the 163 to its best performance because the most experienced pilots were needed elsewhere. 
Me-163 pilots had many problems and one of them is that the landing had to be perfect and that wasn't so easy to do. If a pilot made any mistake during the landing procedure it could prove fatal not only because of injuries, but also because of highly toxic fuel.
Armament:The Rheinmetall MK 108 30MM Cannon
This belt-fed, low velocity cannon with electric ignition served on the Bf-109G-10, the Me-262 & the Me-163 Komet. Although the maximum rate of fire of the MK 108 was only 450 to 650 rounds/min with a muzzle velocity of 1,600 ft./sec (488 m/s) it often took only one or two hits from this powerful weapon to bring down another aircraft.
In many ways, the Rheinmetall-Borsig MK 108 30mm cannon was considered to be a masterpiece of weapons engineering, due to it's compact size, ease of manufacture and hitting power. Although it was first designed by Rheinmetall-Borsig in 1940 as a private venture, the design was finalised in 1942. It met a later RLM requirement for a new aircraft cannon that could knock down enemy bombers with the lowest expenditure of ammunition and stay beyond the range of enemy defensive fire.
In short, the MK 108 was a blow-back operated, rear-seared, belt fed 30 mm cannon using electric ignition and was charged and triggered by simple compressed air. One drawback was that once installed, there was no method to adjust the gun's harmonisation. One distinctive physical feature was the very short gun barrel of 23 inches or 58.4 Centimeters, which gave the MK 108 a low muzzle velocity. The overall length of the gun was 45 inches or 114.3 Centimeters.
The Me-163 was later armed with 50mm projectiles with photocells which were more effective than cannons.

Length
1070 mm
Weight
58 kg
Calibre
30 mm
Rate of fire   
600 rounds per minute





MK 108 ammunition (4)

The 3 cm shell case is made of steel. They come in two colours, brown and green. The firing cap is electrically ignited and the flash channels come in two forms; two small 1.8 mm diameter holes 3 mm apart over the centreline or one 2,5 mm hole in the centreline. The powder charge normaly consists of 30 grams Np rifle powder or 29,5 grams nitrocellulose blade (black ???) powder. The drawings are based on existing shells, measured with a calliper. All have the basic dimensions of 30 x 91 mm. Initial speed (Vo) is 500 m/s.
In the list below, the various types of shells are indentified by a type (which is not of German origin), then the full German name, and followed by the abreviated German name as used in documents. For non-German readers trying to decipher the names, 'Übung' means training or practice, 'ohne Zerleger' means without self-destruct fuze.



Type A, German name: 3 cm Minengeschoss Übung ohne Zerleger (3 cm M-geschoss. Üb. o. Zerleger)
Tar-filled practice mine shell, made of a pressed and rolled steel body with a zinc nose piece to replace the fuze. The driving band is made of red copper and on the inside of the body is an aluminium support ring at the same height as the driving band. Note typical Mineshell round bottom that ensures an maximum explosive charge if used in HE role.




Type B, German name: 3 cm Minengeschoss Übung ohne Zerleger (3 cm M-geschoss. Üb. o. Zerl.)
Tar-filled practice mineshell, made of a pressed and rolled steel body with an steel dummy fuze resembling the AZ1504 as found on 20 mm shells. The body of the shell is the same as type A, except for the fact that the upper part of the body is rolled smaller to receive the smaller 20 mm shell fuzes. This shell is probably an experiment, these shells have never been seen with a AZ 1504.

Type C, German name: 3 cm Sprenggranate Übung ohne Zerleger (3 cm Sprgr. Üb. o. Zerl.)
Practice shell. Machined steel body, pressed steel windshield. Note the different driving band design. Note the small additional powder charge in the shellcase, consisting of finer powder than the main charge. Remains of the bag are found in some shellcases.



Type D, German name: 3 cm Panzersprenggranate Leuchtspur Übung ohne Zerleger (3 cm Pzsprgr. L.spur Üb. o. Zerl.)
Practice armour piercing high explosive tracer shell with dummy fuze. Shellbody and dummy fuze are made of steel. The driving band is made of copper. The shell has the same flight characteristics as the live shell but has no explosive content. Weight of the shell is 500 +/- 7 grams. Dummy fuze: 3 cm Bd. Zerleger Erzatzstuck 1592.
  

Type E, German name: 3 cm Hochgeschwindigheit Panzersprenggranate Leuchtspur Übung ohne Zerleger (3 cm H-Pzgr. L.spur Üb. o. Zerl.)
Practice high speed armour piercing shell with tracer. Shell body and dummy fuze are made of steel, the driving band is made of copper. Weight of the shell is 356 +/- 8 grams.

Type F, German name: 3 cm Sprenggranate Übung ohne Zerleger (3 cm Sprgr. Üb. o. Zerl.)
Practice high explosive shell, machined steel body and bottom plug, copper driving band. The shell has no explosive contents.

Type G, German name: unknown
Tar-filled practice mineshell with an unbalance stick for short range. Pressed and rolled steel body with an steel dummy fuze and an steel unbalance stick. The unbalance stick is bent outward on the top causing the shell to fall into unbalance shortly after leaving the barrel and thereby greatly reducing the range of the shell. Weight of shell: appr. 330 +/- 8 grams. Shell probably of experimental design.

Type H, German name: 3 cm Minengeschoss Übung Ausführung A ohne Zerleger (3 cm M-Gesch. Üb. o. Zerl.)
Tar-filled practice mineshell type A. Pressed and rolled steel body with a steel dummy fuze. The driving band is made of red copper and on the inside of the shell is an aluminium ring to support the driving band. The weight of the shell is 330 +/- 8 grams.

Type I, German name: 3 cm Minengeschoss 108 Ausführung A mit Zerleger (3 cm M-Gesch. 108 Ausf.A m. Zerl.)
Mineshell fuzed with ZZ1589B. Pressed and rolled steel body and an aluminium fuze. Coloured yellow with a 5 mm light green band just under the fuze (meaning self-destruct shell). The shell is filled with 85 grams of HA41 (hexogen aluminium) or 85 grams of penthrite. Weight of shell: 330 +/- 8 grams.


Type J, German name: 3 cm Minenbrenngranate 108 mit Zerleger (3 cm M-Brgr. 108 Ausf.A m. Zerl.)
Mineshell with an incendiary element, fuzed with ZZ1589B. In fact it is the same shell as type I, except for the lower portion of the explosive charge that has been replaced with an incendiary element. It exists of a steel bushing, filled with electrontermit (thermite), ignited by the exploding shell. Thermite burns at a temperature of about 1200 degrees Celsius. Colour: yellow body with a 5 mm wide green and a 5 mm wide blue band under the fuze, green meaning self-destruct and the blue meaning incendiary. Weight of the shell: 370 +/- 8 grams.


Type K, German name: 3 cm Minengeschoss ohne Zerleger (3 cm M-Gesch. o. Zerl.)
Mineshell fuzed with a non-delay AZ1587. Pressed and rolled steel body with an steel fuze adapter between body and steel fuze. The driving band is made of copper and on the inside of the shell is an aluminium ring to support the driving band. The shell is colored yellow overall, including fuze, and only has the letter M stamped on it, in black. The shell is filled with 85 gram HA41. Weight of shell: 330 +/- 8 grams.

Type L, German name: 3 cm Brenngranate ohne Zerleger (3 cm Brgr. o. Zerl.)
Incendiary mineshell fuzed with AZ1587. Pressed and rolled steel body with a steel fuze adapter and an aluminium fuze. The entire shell is filled with a pressed thermite charge, which spews fire like a roman candle after ignition. Thermite burns at a temperature of about 1200 degrees Celsius. The shell is coulored light blue overall, exept for the aluminium fuze. Weight of shell : 330 +/- 8 grams.

Type M, German name: 3 cm Brenngranate ohne Zerleger (3 cm Brgr. o. Zerl.)
Incendiary mineshell fuzed with AZ1587. Pressed and rolled steel body with a steel fuze adapter and an aluminium fuze. The entire shell is filled with an thermite charge, which spews fire like a roman candle after ignition. Thermite burns at a temperature of about 1200 degrees Celsius. The main difference with shell type L is that the shell has a cast thermite load instead of a pressed charge. It also has a steel cylinder in the bottom that functions like a centrifugal weight to balance the shell. The shell is colored light blue overall, exept for the aluminium fuze. Weight of shell: 330 +/- 8 grams.

Type N, German name: 3 cm Minengeschoss Leuchtspur mit Zerleger (day tracer) / 3 cm Minengeschoss Glimmspur mit Zerleger (night tracer) (3 cm M-Gesch. L.spur m. Zerl. / 3 cm M-Gesch. .Gl.spur m. Zerl.)
Mineshell with tracer, fuzed with ZZ1589 B. After firing the tracer ignites, allowing the pilot to observe the flight path of the shell. Day and night versions were available, the latter to prevent the pilot (who had his eyes adjusted to night) being blinded by the fiercer day tracers. The shell is coloured yellow overall, with a 5 mm wide green band just under the fuze, meaning self destruct. Just above the driving band is a light or dark red 5 mm wide band, the light red meaning (fierce burning) daytracer, dark red meaning (low visibility) night tracer. Explosive charge exists of 73 grams HA41 and 3 grams of nitropenta (pink core under the fuze). Weight of the shell : 330 +/- 8 grams.







Type O, German name: 3 cm Minengeschoss Leuchtspur Übung ohne Zerleger (3 cm M-Gesch. L.spur o. Zerl.)Tar-filled practice mineshell with tracer. Fuzed with an dummy steel fuze. In fact the same shell as type N, but practice type. Also found in day and night tracer type. Colour of shell: gray with a light or dark red 5 mm wide band just above the driving band. Weight of shell: 330 +/- 8 grams



Type X, German name: unknown Experimental armour piercing tracer shell, in many ways resembling type E. The outer body is machined to a larger ogive for lower drag. The three notches on the outside of the body make sure the shell stays in line with the barrel. The shell and bottom plug are made of steel, the driving band is made of copper. (photo only)





The Power Plant

The Me-163 Komet was powered by a Walter HWK 509A Rocket Engine. The HWK 509A liquid bi-propellant rocket engine was developed by the Hellmuth Walter Werke in Kiel to power the Me-163 Komet fighter-interceptor. A prototype version of the engine was used in the first powered flight of the Me-163B V2 (second prototype) aircraft in August 1943. Using a fuel mixture of 20% hydrazine hydrate in methanol (C-Stoff) and an oxidizer of 80% concentrated hydrogen peroxide (T-Stoff) along with potassium cupro cyanide as catalyst, the HWK 509A could deliver thrust variables from 330 to 3,750 lbs (150-1,701 kilograms). At full throttle it could drive the Komet to a maximum speed of 596 mph (959 km/h). Maximum time of operation 15-20 minutes. Operational time at full thrust 4 min 11 seconds . However, the Komet carried only enough fuel for 7 ½ minutes of powered flight.

Next part of this article soon: Messerschmitt Me 163 Komet - Versions