Chapter 321 Air-to-Air Missiles

Currently, the German jet engine development department is composed of Germany's own Ernst Heinkel, Italy's Secondo Campini, and Britain's Frank Whittle, all working intensively on the development of the jet engines as requested by Wilhelm.

In comparison to the Me 262 engine with a lifespan of less than 100 hours, Wilhelm aims for the first batch of German jet fighters to have a lifespan of at least 300 hours. The compression system would use either a centrifugal or axial-flow design, with a total compression ratio of around 5, a single combustion chamber, a single-stage turbine, and thrust of approximately 22.5 kilonewtons. The fuel consumption rate should be 0.1 kilograms per newton-hour, with a thrust-to-weight ratio of around 2 to 3.

As for the engine's lifespan, Wilhelm set a strict requirement of at least 300 hours, considering that currently active piston engines often have lifespans extending into the thousands of hours. If a jet engine cannot achieve a lifespan of 300 hours, it would be considered a redundant existence.

These specifications are not unrealistic demands; they are based on the data of the first-generation jet engines developed by the US and the Soviet Union after World War II. These engines were, in fact, improvements made on German jet engine technology.

In other words, Wilhelm hopes that the performance of the first batch of operational jet fighters will match that of the Soviet MiG-15 or the American F-86 Sabre.

Regarding the armament configuration of jet fighters, the MiG-15 from the future is equipped with a 37mm N-37 cannon, two 23mm NS-23KM cannons, and carries 200 rounds.

The F-86 Sabre is armed with either six Browning M2HB 12.7mm machine guns or four 20mm caliber cannons. In later versions, it can also carry 24 2.75-inch "Mighty Mouse" folding-fin aerial rockets (FFAR) capable of cluster launches. Relying entirely on rockets as weapons was a risky choice at the time, so there was a more conventional backup plan with a 20mm cannon.

Of course, advanced guided weapons are the future trend, and Wilhelm cannot ignore research in this area. However, he doesn't need to specifically guide this; in the original timeline of World War II, Germany developed the world's first air-to-air missile—the X-4.

As World War II progressed to the year 1944, approaching the war's end, the situation for Germany became increasingly unfavorable, especially in terms of the crucial air superiority, which was fully controlled by the U.S. and British air forces.

Especially, the large-scale strategic bombing conducted by the U.S. and British air forces severely disrupted Germany's industrial and economic foundations. Faced with the formidable fleets of Allied bombers, the once formidable German Luftwaffe, despite putting in their best efforts to intercept, found itself in a challenging situation. On one hand, the new heavy long-range strategic bombers of the Allies, such as the U.S. B-17 Flying Fortress and the British Lancaster bomber, possessed robust self-defense firepower and heavy armored protection. On the other hand, the Allies, with the continuous deployment of new long-range escort fighters like the P-51D Mustang and P-38 Lightning, made the previous interception tactics of German fighter planes, which involved approaching and firing machine guns at large enemy bombers, obsolete. This situation left Luftwaffe Commander Goering in a predicament. In an effort to regain air superiority, Goering pinned his hopes on new weapons, including new fighter planes and new air-to-air long-range weapons. Among these, Goering himself felt the most practical and effective would be the new air-to-air long-range weapons.

At that time, the onboard weapons carried by fighter planes were mainly large-caliber machine guns and autocannons. Initially, the German forces experimented with using air-to-air rockets. The mainstay German fighter planes like the Fw 190 and Bf 109, as well as the later Me 262, were equipped with air-to-air rockets for combat against Allied aircraft. However, despite the higher firepower of rockets compared to aircraft cannons, their precision was significantly reduced, rendering them ineffective against the Allies.

Under tremendous pressure, in 1943, the German company Ruhrstahl/Kramer took charge of the X-4 project and began the development of air-to-air missiles. Led by Dr. Kramer, the project progressed smoothly. In August 1944, the first batch of test models was delivered, officially named the RK-344 air-to-air missile. It had a maximum speed of 1152 kilometers per hour, a maximum range of 3.5 kilometers, and an effective range of 1.5 kilometers. The wingspan was 0.575 meters, the length was 1.907 meters, and the maximum body diameter was 0.222 meters.

The design of this missile served as the prototype for modern air-to-air missiles, and its fundamental design elements were adopted in subsequent developments. Firstly, it featured four large wings slightly forward in the midsection of the body. At the tail, there were four small tail fins, mirroring the design of future air-to-air missiles. Additionally, its pointed nose resembled that of modern air-to-air missiles.

The RK-344 air-to-air missile was powered by the BMW 109-548 liquid rocket engine, and its warhead weighed 20 kilograms, with a lethal radius of 7.5 meters. This capability was sufficient to destroy any Allied aircraft of that time.

This air-to-air missile has three detonation methods: pilot-controlled, impact fuse detonation, and proximity fuse detonation based on sound sensing. Among them, the proximity fuse detonation relies on the propeller noise of Allied bombers as the sound source for triggering, exhibiting a clever design.

Constrained by the technological conditions of the time, the guidance system of the RK-344 air-to-air missile was wire-guided, meaning the pilot controlled the missile's trajectory using a remote control connected to the missile via a cable. This guidance mode is similar to the guidance system used in contemporary anti-tank missiles.

On the morning of August 11, 1944, a two-seat Fw 190 fighter plane took off carrying two RK-344 air-to-air missiles. After launch, guided by the weapons control officer in the rear cockpit, the RK-344 air-to-air missiles accurately hit the target aircraft. This marked a groundbreaking moment in the history of human aviation—a fighter plane launching and successfully hitting a target with air-to-air guided weaponry for the first time! It ushered in a new era in the history of aerial combat, entering the era of remote guided attacks.

By the end of 1944, during the final testing phase, the RK-344 air-to-air missile, carried by German night fighters, successfully intercepted British heavy bombers "Lancaster" and "Halifax" during night strategic bombing missions, shooting down a total of 7 enemy aircraft! This was the first time in human history that air-to-air missiles shot down enemy aircraft, truly inaugurating a new epoch in aerial warfare history.

By early 1945, owing to its simple structure and ease of mass production, which maintained high production efficiency even with unskilled workers, the Blackwood factory in the Ruhr region produced 1,300 RK-344 air-to-air missile bodies in just a month and a half. Only the accompanying rocket engines were needed before deployment for actual combat. Air Force Commander Goering seemed to have glimpsed the moment of victory. However, at this critical juncture, the rocket engine factory in Stuttgart, Germany, suffered a massive Allied bombardment. All 1,300 rocket engines for the RK-344 air-to-air missiles, which were completed and awaiting transportation, were entirely destroyed. Also lost was the entire production system.

As a result, this world's first air-to-air missile, the RK-344, despite achieving limited success during the testing phase, ultimately failed to enter large-scale combat in a meaningful sense. In reality, at that time, the Allied forces were closing in on Germany's heartland. Moreover, the German Luftwaffe had very few aircraft capable of carrying this missile. Meanwhile, the total number of participating aircraft in the Allied air force had already exceeded 20,000. Hence, even if these 1,300 RK-344 air-to-air missiles could be produced and delivered, they would be unable to impede the course of the war.