R4M
The R4 / M ( R akete 4 kilograms M inenkopf), called "Hurricane" was during the Second World War, the first German-made industrial-scale air-to-air missile that could be really considered as operational.
During the short period of their front-line use, it was mainly used to equip the Messerschmitt Me 262 and Focke-Wulf Fw 190 fighter aircraft . The missile was designed as a response to the closely staggered formations of the increasingly heavily armored American B-17 and B-24 , as the previous conventional combat with the help of 13-mm and 15-mm machine guns ( MG 131 and MG 151 ) as well the 20 mm on-board cannons ( MG FF or MG 151/20 ) showed less and less success.
development
In 1944, the Reich Aviation Ministry demanded a space-saving rocket with a tail unit for fighting bombers. Contrary to the usual practice of developing rockets for the Luftwaffe exclusively at the RLM, the Deutsche Waffen- und Munitionsfabriken in Lübeck and the Curt Heber Maschinenfabrik (HEMAF) company in Osterode am Harz received the development contract in September 1944, which was completed by spring 1945.
Structure and mode of operation
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The R4 / M consisted of the three assemblies
- Warhead with detonator ,
- Rocket engine and that
- Folding tail that unfolded after takeoff.
Warhead
The R4 / M had a mechanical Rheinmetall Borsig - impact fuse of the type AzRz 2 with a Detonatortablette of 85% lead azide and 15% lead styphnate , an 8-gram boosters (Zdlg 34 NP) from 90% PETN and 10% wax , as well as a 400 g heavy castable main charge made of HTA 41 (45% trinitrotoluene , 40% hexogen , 15% aluminum powder ). HTA 41 was an explosive with increased gas impact that had been specially developed for the R4 / M at DWM. The detonator was screwed onto the conically shaped warhead made of deep-drawn sheet metal (0.8 mm wall thickness).
Rocket engine
The rocket motor consisted of a combustion chamber with a length of 375 mm, an inner diameter of 45 mm and a nozzle with a 13 mm clamp welded to the combustion chamber . It contained 875 g of a double-base powder based on diethylene glycol dinitrate in the form of powder sticks as fuel . After a burning time of 0.8 s (about 200 m flight distance) the R4 / M reached its maximum speed of 525 m / s (about 1900 km / h).
Folding tail
At the end of the rocket motor in the area of the nozzle, eight spring-loaded fins were attached, which were secured with a thin wire, which came off after the launch of the rocket and released the fins.
Application and mode of action
The R4 / M was installed under the wings either in rail or pipe grids, called a honeycomb . Twelve to thirteen rockets were usually attached under each wing of an Me 262, but six or 24 rockets were also possible. The rockets were launched as a volley; The rockets were fired in groups of three with an interval of 7 milliseconds. The rockets had an impact fuse, a combined impact / time fuse ZZRI was still being tested. In this case, a delay charge was ignited during firing, which caused the warhead to explode after 5 seconds if the missile did not hit a target.
The effect of the R4 / M missile was always based on the mine effect (more precisely: the air blast effect) of a direct hit and not on the fragmentation effect of a near hit, as was the case, for example, with anti-aircraft grenades. The R4 / M's warhead did not have a noteworthy fragmentation effect, even due to the thin-walled steel casing.
During the attack with the R4 / M, the Me-262 fighter aircraft approached the enemy bomber pulks from behind. This type of attack was in contrast to the early tactics of the Bf-109 and Fw-190 fighter pilots, who often attacked the enemy bomber formations head-on in order to bombard the less well-protected front areas of the enemy bombers with on-board weapons .
The placement of hits was relatively easy due to the extended trajectory of the tail stabilized missile. Due to the high initial speed of the rocket and the relatively large area covered by a full rocket salvo, it was extremely difficult to avoid the cumbersome bombers in good time, especially because, due to the close formation flight, no evasive maneuvers could be flown without a collision with one's own aircraft to risk.
Even a single hit by a rocket was usually devastating for the aircraft. A hit in the fuselage of a bomber could tear a gaping hole in the planking. In the event of a hit on the wings, either the fuel tanks housed in them exploded or the supporting structure was damaged to such an extent that the wing broke due to the high cruising speed of the aircraft. This also applied to the extremely robustly built B-17 Flying Fortress .
production
The production took place from the beginning of 1945 in Osterode am Harz in the Curt Heber machine apparatus factory (short: machine factory Curt Heber or Hemaf ). A total of 20,000 missiles were ordered, of which around 10,000 had been completed by the end of the war. In April 1945 DWM in Lübeck received another order for 25,000 R4 / M units.
Testing and use
The first R4 / M was tested in February 1945 by Jagdverband 44 under Adolf Galland, which was set up in the same month . About 60 Me 262s were equipped with R4 / M within a month . In addition to the Me 262, the rocket fighter Me 163 and the conventional Fw 190 were also equipped with the unguided R4 / M. The object protection fighter Bachem Ba 349 Natter, which was no longer used, was to contain a launch system called a honeycomb with 28 tubes for R4 / M missiles in the bow . However, a start attempt failed and the bug exploded.
Although aerodynamic difficulties were feared with the Me 262 and Me 163, the mounting of the 24 R4 / M missiles on the underside of the wing did not significantly affect the flight characteristics of these two models. Test pilot Fritz Wendel testified that the Me 262 flies “not five kilometers slower” and had no complaints. The first flight of a Me 163 with the R4 / M armament by Adolf Niemeyer also went smoothly.
The new rocket was used for the first time on March 18, 1945 when 1221 bombers with 632 fighters attacked Berlin as escort. Six Me 262s of JG 7 fired their 144 R4 / M missiles at the bomber formation and then attacked it with on-board weapons. The Allies lost 25 bombers. During this mission two Me 262s were lost and one pilot was killed. English-language sources mostly give different numbers about this "last great air battle in World War II". According to these, 37 Me 262s shot down a total of twelve bombers and one escort fighter, while three Me 262s were lost.
In German sources, the success of the R4 / M is described as “excellent” and “outstanding”. In the short period of use, almost 500 Allied aircraft are said to have been destroyed by the R4 / M. For example, when deployed from a formation of 425 B-17 G 25 machines are said to have been shot down without losing their own. In April 1945, 24 Fw 190s with the R4 / M 40 B-24 are said to have shot down without any losses of their own.
Regardless of the actual number of kills, the R4 / M was undoubtedly the most effective weapon used by German fighter pilots in the last months of the war. The numbers on both sides speak for the effectiveness of the jet fighter in combination with the rocket armament. However, due to their enormous numerical superiority, the loss rate of the Allies was so low that the use of the R4 / M no longer had any decisive effects.
The correctness of the concept of attacking bomber formations with volleys of unguided missiles is also demonstrated by its continuation in the US Air Force in the years after the Second World War for the aircraft types F-86D Saber , F-94 Starfire , F-89 Scorpion and F-102 Delta Dagger occupied. The FFAR introduced by the USA in the 1950s was based on the same structure as the R4 / M.
Derived missile types
The Panzerblitz II and Panzerblitz III from the R4 / M were developed against armored ground targets . In the Panzerblitz II, the mine head was replaced by a large shaped charge head of 130 mm caliber that could penetrate 180 mm of armor steel . Because the Panzerblitz II only reached a flight speed of 370 m / s due to the large warhead, the Panzerblitz III was developed at the German weapons and ammunition factories, which carried a modified shaped charge grenade 75 mm HL.Gr.43 as a warhead. The Panzerblitz III reached a flight speed of 570 m / s and could penetrate up to 160 mm of armor steel at an angle of impact of 90 °; however, only a few samples were built.
Technical specifications
| Manufacturer | HEMAF, Osterode; DWM, Lübeck |
| power | |
|---|---|
| Speed (Vmax) | 525 m / s |
| Speed after 1000 m | 125 m / s |
| Burn time | approx. 0.8 s |
| Thrust (max) | 245 kp (2.4 kN) |
| Control range | up to 1.5 km |
| drive | Solid rocket engine |
| Weight | |
| Total mass | 3.85 kg |
| Propellant charge | 0.815 kg |
| Warhead | 0.52 kg |
| Detonator | Impact fuse |
| dimension | |
| length | 812 mm |
| diameter | 55 mm |
| Stabilizer span in flight | 242 mm |
| price | |
| 1944 | 2 batteries 500 each |
| 1945 | 2 batteries ℛℳ 750 each |
Web links
- German Air Force - R4 / M "Orkan"
- Private website "www.alpha64.de": 1945 - The end of the war in Osterode am Harz
Individual evidence
- ^ A b c d L. E. Simon: German Scientific Research Establishments. Mapleton House, New York 1947.
- ^ A b Heinz J. Nowarra: The German Air Armament 1933–1945. Volume 4, 1993, p. 87.
- ↑ LE Simon: Secret Weapons of the Third Reich German Research in World War II. WE Publishers, Old Greenwich 1971, p. 128.
- ↑ a b Mano Ziegler : Turbinenjäger Me 262. 5th edition, 1993, pp. 177-185.
- ↑ Mano Ziegler: Raketenjäger Me 163, 11th edition, 1992, p. 189.