Colin Heaton: The Me 262 Stormbird

Messerschmitt was awarded the initial probationary contract to design a strong and functional airframe around the axial-flow turbojets being developed by BMW. The engines were expected to produce 1,323 pounds (600 kilograms) of thrust and be tested, proven, and ready for production by December 1939. The upgraded version would produce around 1,984 to 2,000 pounds of thrust, and with two Jumos mounted, the Me 262 showed great promise. In proper German fashion, the design and development process was not conducted with tunnel vision, as the research conducted by Waldemar Voigt examined the concepts of using both single-engine and twin-engine jet designs.

By May 1940, the inaugural static tests were completed with the recommendation for further strengthening the airframe and wing spars to better support the powerplants, which was soon implemented. Following these modifications and a slight redesign of the mounts, the Me 262 was a cleaner and better aerodynamic design according to wind tunnel tests, exceeding the expectations of all involved.

The design of the fuselage had not undergone too many drastic changes from the original concept. The Me 262 was always a “swept wing” design, although the degree of sweep was established at 18.5 degrees following wind tunnel tests. This was decided after the proposed engines proved to be somewhat heavier than originally planned, so weight distribution and aerodynamic integrity were the primary considerations. The design also addressed the aerodynamic considerations relative to the position of the center of lift due to thrust relative to the center of mass, thereby increasing the aircraft’s speed.

The swept wing design had been presented in 1935 by Adolf Busemann, while Prof. Herbert Wagner’s airframe design work at Junkers was not unknown (as well as the internal fighting between Wagner and Otto Mader working on the Jumo engines), and upon further collaboration Willi Messerschmitt had advanced the concept within his design in 1940. In April 1941, it was proposed that the Me 262 design incorporate a 35-degree swept wing ( Pfeilflügel II , or “arrow wing II”). Ironically, it would be this same wing sweep angle that would be used later on both the North American F-86 Sabre and Soviet MiG-15 fighters, the two primary jets that would duel in the skies over Korea. Although aerodynamically sound on paper, and feasible in a production application, this wing design concept was not used in the final design. Messerschmitt continued with the projected HG II and HG III ( Hochgeschwindigkeit , “high speed”) designs, producing test versions in 1944, which were designed with both a 35-degree and 45-degree wing sweep in test models.

Messerschmitt’s test pilots conducted a series of flight tests with the production series of the Me 262. In dive tests, it was determined that the Me 262 went out of control in a dive at Mach 0.86 and that higher speeds led to a nose-down attitude, resulting in a freezing of the stabilizers that could not be corrected, as mentioned later in this project by pilots who experienced this phenomenon. The resulting uncontrolled steepening angle of the dive would in turn lead to even a higher speed, airframe stress, and structural compromise and possible disintegration of the airframe due to the increased negative g stress.

The stress of g forces could prove deadly in any aircraft, but in the Me 262, it was often fatal. Unless the pilot was prepared, any quick movement could be his last, as experienced by Oberfeldwbel Hermann Buchner during a mission on April 8, 1945, as cited in Foreman and Harvey:

“I flew a rotte operation (two aircraft) in the Hamburg area. At about 8,000 meters over the city I spotted a Spitfire, 1,000 meters lower, flying north. I looked for bombers, and awaited instructions from ground control. A few minutes later, this aircraft, which appeared to be a reconnaissance aircraft, returned, heading northwest towards the Elbe. Since I was in a good tactical position, I was able to close very fast on the Spitfire from behind without being seen.

“It was going very fast, and in the final moment I believe that the Tommy was able to turn his aircraft to come at me head-on. Then I made a mistake; instead of opening fire, I broke to the left, so hard that my aircraft flicked over and went down out of control. I was momentarily terrified and then had my hands full trying to get the aircraft back to normal flight. By this maneuver, I lost my wingman, and thus we returned to Parchim separately. I was richer from the experience, although no success was granted to me. I believe also that our nerves were unduly stressed.” {3}

In an interview with author Colin Heaton, Buchner had this to say about the electronic trimming issues he faced: “The jet was an absolute wonderful thing to fly when all was well. But when things were not well, you were in a nightmare. If the aircraft rolled and lost engine compressibility, you had better get out; you were not going to recover, especially if a flat spin was the result. Another thing was the negative g forces that could be experienced, if inverted, especially at high speed could very easily, and in my case did on occasion, render the electric trimming capabilities useless. You were not getting out of a dive if that happened either. I know that many pilots were lost because of this fact.” {4} (Jorg Czypionka, however, stated that these problems were not conclusive.)

The HG test series of Me 262 prototypes was estimated to be capable of breaking Mach 1 numbers in level flight, if operating at higher altitudes. Naturally, this depended upon the reliability of the proposed engine powerplants, and the durability of the airframe. What was unknown at that time was the effect of breaking the sound barrier, that mystical wall that was more of a theory at this time than a reality, since it had never been breached. It seems ironic that, given the desires for faster fighters, and the known capabilities of the V-2 rockets that emerged as a regular weapon of choice in 1944, Willi Messerschmitt never pursued a program to surpass the estimated Mach 0.86 limit for the Me 262 in the streamlined fighter mode.

The first pilot to break 1,000 kilometers per hour in level flight was Feldwebel Heinz Herlitzius, in work number 130007, marked as VI+AG, on June 25, 1944. Hans-Guido Mutke (later interned in Switzerland) may have been the first pilot to exceed Mach 1 in a vertical 90-degree dive on April 9, 1945. Mutke did not have the required on-board instruments to record the actual speed, and all pilots knew that the pitot tube used to measure airspeed can give improper readings as the pressure inside the tube increases at high speeds. Finally, the Me 262 wing had only a slight sweep incorporated for trim reasons and likely would have suffered structural failure due to divergence at high transonic speeds. It is possible that an Me 262 (HG1 V9, work number 130004) with the identifier of VI+AD was built with the low-profile Rennkabine racing canopy to reduce drag, and this jet may have achieved an airspeed of 606 miles per hour. {5}

After the war, the British tested the Me 262, trying to exceed Mach 1. They did achieve speeds of Mach 0.84, and during this process they also confirmed the results of the German dive tests, where British pilots discovered what the Germans already knew: Steep dives and high speed meant death at a certain point. Captured jets were also tested by the Americans and Soviets. Everyone was impressed with the design and its capabilities.

The Messerschmitt name had already been synonymous with excellence in aircraft designs and production. The single engine, single-seat Bf 109 series (also known as the Me 109 by the Allies and is so designated throughout the rest of this book) was the most widely produced combat aircraft in history, with some 35,000 units being produced. The additional inclusion of the twin engine Bf 110 Zerstörer (Destroyer), as well as the later Me 210 and 410 models for reconnaissance and night fighting, had cemented Willi Messerschmitt as a designer favored by Hitler and the hierarchy.