JU 88 G-6

 

 

 

The crew of the JU88 G6 that shot down MZ-467 in the early hours of the 17th April were: Ofw Schmidt (pilot), Ofw Michels (radio operator), Fw Kretschmer (radar operator), Uffz Heidsiek (air gunner).

The G-6 entered production in the middle of 1944. It was powered by 1,750hp Jumo 213A engines, and had a top speed of 360mph, an increase of 25mph on the G-1. It carried four 20mm cannon in a pod under the fuselage. It carried the full range of radar equipment available to the Luftwaffe in 1944-5, including the FuG 220, 218, 350 and possibly the FuG 240. It entered combat in late 1944, too late to have any impact on the war.

Some information about the radar which more than likely was the model used on Schmidt's aircraft: Source wikipedia

FuG 217: Installed mainly in Ju 88 G-6, only a few Bf 110 G-4, He 219 or Me 262 received the Neptun. It could be combined with the additional Elfe device to automatically measure the target distance and fire the guns at a pre-set range.

Manufacturer: FFO
R2 version (backward warning device)
J2 version (for single-engined night fighters)
Ausführung V/R (combined night fighter and backward warning device for two-engined fighters)
Two switchable frequencies: 158 and 187MHz
Search angle: 120°
Range: 400 to 4,000m
Spike or "antler" antennas

 

The photos below show the FuG 217 radar, many thanks to johannes bruening for allowing me to use these photos

 

FuG217 with case opened showing internal components

Photo:www.funkstunde.com (Used with permission)

 

Author: Oberkommando der Luftwaffe,

Generalnachrichtenführer, Ln.-Inspektion - 6 Abtlg. - (1D), Gosewitch

FuG217 with screen goals

Photo:www.funkstunde.com (Used with permission)

 

 

 

FuG217 installed in aircraft cockpit

Photo:www.funkstunde.com (Used with permission)

 

 

 

 

Jumo 213 A - Supercharged inverted V12 engine

General:
Manufacturer: Junkers
Type: Supercharged liquid-cooled inverted Vee piston engine
Cylinders: 12
Bore: 150 mm (5.9 in)
Stroke: 165 mm (6.5 in)
Displacement: 35 L (2,135 in³)
Length: 2,266 mm (89.2 in)
Dry weight: 940 kg (2,072 lb)

Power output:
– 645 kW (865 hp) at sea level
– 716 kW (960 hp) at 3,000 m (9,850 ft) at 2,450 rpm
Specific power: 25.8 kW/L (0.57 hp/in³)
Compression ratio: 6.93:1
Specific fuel consumption: 0.33 kg/(kW·h) (0.54 lb/(hp·h))
Power-to-weight ratio: 1.36 kW/kg (0.83 hp/lb)

Components:
Valvetrain: Three valves per cylinder.
Supercharger: Two-stage two-speed centrifugal type
supercharger with MW50 injection into the intake
and an aftercooler.
Cooling system: Pressurized water up to 120°C (248°F)

Performance:
Power output:
– 1,287 kW (1,725 hp) at 3,250 rpm for takeoff;
rated altitude 9,600 m (31,500 ft)
– 1,508 kW (2,020 hp) for takeoff with MW50 injection
Specific power: 36.8 kW/L (0.81 hp/in³)
Compression ratio: 6.5:1 (B4 fuel, 87 octane)
Power-to-weight ratio: 1.37 kW/kg (0.83 hp/lb)

 

Photo:Wolfgang Bredow

 

The Jumo 213 was a World War II-era V-12 liquid cooled aircraft engine, a development of Junkers Motoren's earlier design, the Jumo 211. The design added two features, a pressurized cooling system that required considerably less cooling fluid that allowed the engine to be built smaller and lighter, and a number of improvements that allowed it to run at higher RPM. Although these changes may sound fairly minor, they boosted power by over 500 hp and made the 213 one of the most sought-after engine designs in the late-war era.
When the Jumo 211 entered production in the late 1930s it used a normal liquid cooling system based on an "open cycle". Water was pumped through the engine to keep it cool, but the system as a whole operated at outside air pressure, or only slightly greater. Since the boiling point of water is effected by pressure, this meant that as the aircraft climbed the temperature of the cooling water had to be kept quite low to avoid boiling, which in turn meant that the water removed little heat from the engine before having to be moved to the radiator to cool it. In contrast, the Daimler-Benz DB 601 used a pressurized system that ran at the same increased pressure at all altitudes, raising the boiling point to about 110°C. This allowed it to use considerably less water for the same amount of cooling power, and it retained this power at all altitudes. Although otherwise similar in most respects, the 601 was smaller and lighter than the 211 and could be run at higher power settings at higher altitudes, making it popular in fighter designs. The 211 was relegated to "secondary" roles in bombers and transports.

Junkers was not happy with this state of affairs, and started their own efforts to produce a pressurized cooling system as early as 1938. Experiments on the 211 proved so successful that it became clear that not only could the engine be built smaller, but could be run at higher power settings without overheating. Additional changes to strengthen the crankshaft and add a fully-shrouded supercharger for increased boost resulted in the Jumo 211F model, which delivered 1,400 hp at 2,400 RPM, up from 950 hp at 2,200 RPM in earlier versions.

But this was only the beginning. After redesigning the engine casing to a smaller size to suit the increased cooling power and then further increasing boost settings on the supercharger, the resulting 213A model was able to deliver 1,750 PS (metric hp) at 3,250 RPM. This made it considerably more powerful than the corresponding DB 601E which provided 1,350hp, and about the same power as the much larger DB 603. Junkers decided to go after the 603's market, and made the 213's mounting points and fluid connections in the same locations as the 603, allowing it to be "dropped in" as a replacement.

The 213A first ran in 1940, but experienced lengthy delays before finally being declared "production quality" in 1943. Production was extremely slow to ramp up, in order to avoid delays in the existing Jumo 211 production. By the time the engines were available in any sort of number in 1944, Allied bombing repeatedly destroyed the production lines. Production of the A models was limited to about 400-500 a month for most of 1944/45.

A range of advanced versions were also developed during the lengthy teething period. The 213B was designed to run on 100 octane "C3" fuel, allowing the boost pressure to be increased and the take-off power improved to 2,000 PS. The 213C was essentially an A model with re-arranged secondary equipment (supercharger, oil pump, etc.) to allow a cannon to fire through the propeller shaft. The 213D added a new three-speed supercharger for smoother power curves and improved altitude performance, but it was decided to skip over this version.

Instead the next major version was to be the 213E, and the similar 213F. These engines were equipped with a new two-speed, two-stage supercharger that dramatically improved altitude performance. The only difference between the two models was that the E included an intercooler for additional high-altitude performance, while the F model removed this and was tuned for slightly lower altitudes. The E and F models were in high demand for many late-war aircraft, including the Junkers Ju 188, Junkers Ju 388, models of the Focke-Wulf Fw 190 and the Focke-Wulf Ta 152H.

A more major upgrade was projected as the 213J, which replaced the earlier model's three valves with a new four-valve-per-cylinder design for increased volumetric efficiency. There was no time to work this change into the production line before the war ended. Other experimental models included the 213S for low-altitude use, and the turbocharged 213T.

Source:wikipedia.org

 

MG 151 - Maschinengewehr 151

(The single-barrel automatic cannon used to shoot down MZ-467)

Mg 151/15 Specifications:
Type: single-barrel automatic cannon
Caliber: 15 mm x 96
Operation: Recoil-operated; short recoil
Length: 1916 mm
Barrel length: 1254 mm
Rifling: 8 grooves, right twist, 1 turn in 16"
Weight (complete): 38.1 kg (84 lb)
Rate of fire: 740 rpm
Effective range: 400 m
Muzzle velocity:
HE-T, HEI-T: 960 m/s
AP-T: 850 m/s
AP WC: 1030 m/s
Projectile types:
AP-T, weighing 72 g
AP(WC), weighing 52 g
HE, weighing 57 g/HE filler: 2.8 g
Mg 151/20 Specifications:
Type: single-barrel automatic cannon
Caliber: 20 mm x 82
Operation: Recoil-operated; short recoil
Length: 1766 mm
Barrel length: 1104 mm
Rifling: 1 turn in 23
Weight (complete): 42.7 kg
Rate of fire: 750 rpm
Effective range: N/A
Muzzle velocity:
M-Geschoss: 805 m/s
HE-T, AP: 705 m/s
Round types:
M-Geschoss
HE-T, AP


The MG 151 (MG 151/15) was a 15 mm autocannon produced by Waffenfabrik Mauser starting in 1940. It was in 1941 developed into the 20 mm MG 151/20 cannon which was widely used on many types of German Luftwaffe fighters, fighter bombers, night fighters, ground attack and even bombers as part of or as their main armament during World War II. The 20 mm MG 151/20 was also fitted on the Italian World War II fighter aircraft of the "Serie 5", the most effective Italian fighters of WWII.
The 15 mm MG 151 was found to have lackluster performance as the main gun on Messerschmitt Bf 109 early F-2, and was soon replaced by the 20 mm version to become the standard cannon for the Bf 109F-4 series onwards until it was superseded by the 30 mm MK 108 cannon.

To create the MG 151/20 round, Mauser simply necked out the MG 151/15's case (i.e. enlarged the opening of the case where the shell fits in) to fit a 20 mm shell—which, incidentally, was the same shell used in the MG FF cannon—and shortened the length of the case so that the total length of the complete round was the same for both calibres. These measures simplified conversion of the cannon between calibres, so that it was possible to convert the 15 mm to the 20 mm MG 151/20 simply by changing the barrel and making other small modifications. However, this simple modification-based approach was not without its drawbacks. The relatively short case of the 20 mm round, coupled with the larger and heavier 20 mm projectile cost some muzzle velocity (950 m/s for the 15 mm round vs. 800 m/s for the 20 mm round—a 16% drop). However, in comparison to the earlier MG FF cannon, the MG 151 had a higher muzzle velocity which gave it a more predictable trajectory and higher impact velocity/longer range.


Nevertheless, the extra HE capacity was considered well worth the loss in muzzle velocity. The basic 20 mm HE round, for example, had almost 30% more explosive content by weight than the 15 mm shell. Furthermore, the MG 151/20 also used the Minengeschoß ("mine shell"), which was made using drawn steel (similar to making cartridge cases) instead of being cast, as was typically done to make cannon shells at the time. The result was a shell with very thin yet strong walls, and hence a very large explosive (or incendiary) capacity. Indeed, the 20 mm M-shell carried 6-8 times the amount of explosives contained in the 15 mm shell. The new 20 mm shell was relatively effective against enemy aircraft, with the possible exception of heavily built bombers such as the B-17 Flying Fortress or Avro Lancaster. German statistics data showed that on average the 151/20 required an average of 25 hits to down a B-17, while 18-20 hits were required to down other 4-engine bomber types, and only four hits were required to down a single-engine fighter. While the larger round rapidly replaced its predecessor—the MG 151/15 was phased out in 1942—German engineers continued research into an even heavier cannon that could rapidly demolish heavy enemy bombers.

20mm M-Geschoss shell.
Two versions of the 20 mm MG 151 were built: one with a percussion priming system and a second E-model with electrical priming. Some rounds were available with a timer self-destruct and/or tracer (or glowtracer). There were also different types of high explosive shell fillings with either standard PETN, a mixture called HA41 (RDX and aluminium), and a compressed version where more explosives were compressed into same space using large pressures.
Eight hundred MG 151/20 were exported to Japan by a submarine in August 1943 and were used to equip 388 Japanese Ki-61-I Hei fighters.

The 20 mm MG 151/20 was also fitted on the Macchi C.205, the Fiat G.55 and Reggiane Re 2005, the most powerful Regia Aeronautica fighter aircraft, built around the Daimler-Benz DB 605 engine.

After WWII, numbers of ex-Luftwaffe MG 151/20 cannon were removed from inventory and from scrapped aircraft and used by various nations in their own aircraft. The French Air Force and French Army aviation arm (ALAT) utilized MG 151/20 cannon as both fixed and flexible armament in various aircraft, including helicopters. The FAF and ALAT jointly developed a rubber-insulated flexible mount for the MG 151/20 for use as a door gun, which was later used in combat in Algeria aboard several FAF/ALAT H-21C assault transport helicopters and on HSS-1 Pirate gunship helicopters. French Matra MG 151 20mm cannons were used by Portugal, Rhodesia and South Africa fitted to their Alouette III helicopters.

The 15mm caliber is similar to a 14.5mm round, developed in World War 2 for the Soviet PTRD and PTRS antitank rifles and used in post-war heavy machine guns. Recent developments of 14.5mm High Explosive Incendiary rounds may be regarded as a revival of the 15mm cannon concept.

[Source - Wikipedia]