The Ruhrstahl X-4 missile was a World War 2, German-designed air-to-air missile, the first air-to-air missile of its kind to be produced. It is the earliest air-to-air missile that is available in War Thunder, and is available on the tech tree Fw 190 F-8. Let us dive into the interesting history of the missile, and later talk about how to use this unique missile!
History
The Ruhrstahl X-4 was first proposed by a German engineer by the name of Max Kramer during the later stages of World War 2, a period when the Allies were now bombing the German homeland. As losses mounted, the German military was in desperate need of a new weapon to counter Allied bombings, without suffering heavy losses of its own. Design work on the X-4 began in mid-1943 under Kramer at Ruhrstahl AG. The goal was to create an air-to-air rocket, capable of destroying enemy bombers before the firing aircraft was within the bomber formation’s effective 1,000-meter gunning range, to which the X-4 handily met these requirements.
After completion, the X-4 was tested on the on the Focke-Wolf 190, specifically the Fw 190 F-8 on August 11, 1944, and later on the Me 262 fighter jet. The Germans initially planned to use the missile on fast fighters like the Fw 190, but testing revealed that pilots struggled to control both the aircraft and the missile at the same time. This deficiency led to the X-4 being re-directed to 2-seater planes like the Ju 88 bomber, as the second crew member would be able to focus entirely on guiding in the missile without having to fly the aircraft.
After testing, production of the X-4 began in 1945. The missile’s simple assembly and use of readily available materials allowed for its mass-manufacturing, at least for its time. Skilled labor was for the most part unnecessary, and the missile was fairly inexpensive to produce in large quantities. Approximately 1,000 missiles were built before Allied bombing of the Ruhrstahl factory brought production to an end.
The X-4’s legacy continued after the war, when the French developed a domestic variant known as the Nord SS.10. Although inspired by the X-4, the Nord SS.10 was designed as an air-to-ground missile rather than an air-to-air weapon. Production of the SS.10 ended after only about 200 units, due toa hazardous pre-flight fueling procedure and the arrival of more modern designs.
Qualities
The X-4 performed quite well in its intended role as an air-to-air weapon. Powered by a BMW 109-448 rocket motor, the X-4 could reach near-supersonic speeds of 1,150 km/h. It had a range of 1.5 to 4 km and used a hypergolic mixture of S-Stoff and R-Stoff as propellant, though its fuel capacity was limited. The Germans had eventually planned to replace the liquid-fueled motor with a solid-fuel version, to simplify handling and improve reliability.
The missile was spin-stabilized at 60 RPM, or roughly one rotation every second. It had an MCLOS guidance system and the signals that controlled the X-4 were sent via two wires which were connected to a joystick that the pilot used to control the missile’s pitch and yaw. This wire-based control method was used to prevented enemy radio jamming of the missile. The missile carried a 20 kg fragmentation warhead with a Kranich proximity fuze.
Statistics
| Projectile mass | 60 kg |
| Guidance | MCLOS (Manual) |
| Maximum speed | 0.9 Mach or 1150 km/h |
| Missile guidance time | 33 seconds |
| Explosive type | Nipolit |
| Explosive mass | 7.5 kg |
| TNT equivalent | 9 kg |
Gameplay
This section explains how to use the missile effectively in combat. Once you learn to control it properly, the missile becomes surprisingly fun to use. The missile guidance system for the X-4 is MCLOS (Manual), and as such it can be hard to use without adequate practice.
Maneuvering the X-4 is posed as quite a challenge, but it is not difficult when it is maneuvered properly. To maneuver the missile, it is recommended to turn off relative controls, to ensure that the missile moves only when you have pressed the button. It is easier to slow down before your target, to maximize time for guidance. You should decrease your throttle to approximately 30% to ensure that the plane is not too slow, and to decrease speed swiftly. Just remember to increase throttle after hitting your target.
Mounted as an unlockable air-to-air weapon on the Fw 190 F-8, the X-4 gives F-8 players a unique option to use with the only guided air-to-air missile at its rank. Other than rockets fired with a 1000m self-destruct setting (which have a very short effective range even in this case), no other aircraft that it faces has this kind of long-ranged aerial armament, making it truly one-of-a-kind.
Dogfighting
The Germans developed the X-4 to destroy enemy bombers from a safe distance, and this is still the best way to use it in-game. However, if a plane is closing in on your position looking for a dogfight, you can try firing a X-4 at them in a head-on encounter to either force them to pull out of the way or be hit by the missile. However, as the X-4 has poor acceleration, launching from too close a distance may not give the missile enough time to pull in to hit the target, even if you hold down the controls accordingly.
Warning: When using the X-4, the controls for the missile’s movement are on PC by default “Alt + WASD”. Do note that the W key makes the missile go down instead of up, and the S key makes it go up instead of down.
Ground Attack
The X-4, contrary to its in-game weapon classification, can also be used as a pseudo-air-to-ground munition, much in the same way its spiritual successor, the SS.10 was meant to be used as. Its low TNTe of only 9 kg means that a direct or near-direct hit is required on even open top enemies, although the missile’s somewhat slow firing speed makes adjusting its course reasonably doable. An evolution of this playstyle can be seen in the later ranks, with the West German G.91 and its AS-20 Nords.
Fw 190-F8 Weapon Setup
After the introduction of the X-4 to the game, a common question is whether or not you should use the X-4, or use the MK 103 30mm cannons instead of the (admittedly somewhat gimmicky) AAMs. This section aims to help answer those questions, and hopefully let you decide which one fits you better.
You can add two 30 mm MK 103 cannons on the Fw 190-F8, that have 35 rounds per gun and a maximum penetration of 77 mm. The MK 103s are exceptionally deadly, and unlike their slow-velocity MK 108 cousins, sport fairly high shell speeds and a lethal explosion on hit. Dangerous against both aircraft and tanks equally, so long as you can aim your shots the MK 103s bolster the Fw 190 F-8's lethality by orders of magnitude.
For comparison, the X-4 is a missile that, however slow, can still fly at near supersonic speeds, meaning that if you launch it at a reasonable (usually 1.5-2km or closer) distance, it will be near impossible for the enemy to simply try outrunning it. If your main target is enemy bombers, the X-4 can also be quite lethal, as it allows you to engage bombers even with an altitude disadvantage so long as you get in reasonably close to them — and you can also simply stay out of their effective gun range to begin with! Against enemy fighters, most aware enemies will be able to dodge the somewhat slow, hard to aim missiles, and some may even exploit the fact you can’t control your aircraft while aiming the missile to fire an accurate burst at your plane before pulling out of the head-on, so using the missiles can be a risk. However, they are certainly very unique, and the satisfaction of getting a missile kill you manually aimed yourself is second-to-none, so I would suggest giving it a try regardless.
All-in-all, the MK 103s will be better for CAS (Close Air Support) due to their longer trigger time, lethal penetration and flexibility, while the X-4 will be superior against lumbering aerial targets or the rare open-top enemy SPAA/SPGs you may encounter if playing Ground Battles; pick and choose accordingly, the F-8 has a diverse set of ordnance for any situation!
