The Development of the He 162 Aircraft

The development work went ahead at the highest tempo. Most of the people involved in the design work worked 90 to 100 hours a week and even slept sometimes in their offices. Air-attack alarms in Vienna and transportation difficulties frequently disrupted their work.41 Relatively little testing was done with aerodynamic models during the development phase, mainly in the wind tunnels of the LFA in Braunschweig and of the AVA in Göttingen, but some of these tests started only after manufacture of the prototypes was underway.

From early on Heinkel planned to produce two basic variants of the aircraft: a singleseat fighter and a double-seat trainer. Experience with the Me 262 clearly showed that training or converting pilots to fly jets was not simple at all, and a trainer was viewed as indispensable. Galland demanded that 3 percent of the production be trainers. Two type trai ners were to be constructed: a wooden glider similar in form to the real aircraft, intended for basic handling training, and a powered version with a limited fuel supply for advanced training.43 At about that time some people in the Reich’s leadership started to refer to the He 162 as the Volksjäger, or “People’s Fighter.”44 The origin of this nickname is allegedly in an idea Colonel-General Alfred Keller, the head of the National Socialist Flying Corp (NSFK), brought up in late summer 1944. Keller conceived a small jet fighter which could be flown in large numbers by hastily trained young pilots.45 There is no evidence that this concept in any way influenced the decision makers to initiate the light-fighter program in early September, and the term had never been used in the correspondence of the firms involved in the program, nor in Luftwaffe’s documents dealing with the aircraft. However, the name soon became unofficially associated with the plane.46 Such a name was in line with a trend existing at that time to use the prefix Volk in relation to different military organizations and an assortment of weapons—usually very basic and cheap. It should also be remembered that on 25 September—two days after authorizing the aircraft—Hitler announced the establishment of the German National Guard—the Volkssturm. Just like the name of this popular militia, Volksjäger was a purely propagandistic term supposed to represent the totality of the war for Germany. The popular nature of the plane was further enhanced when Saur dovetailed Keller’s original idea and suggested to train Hitler Youth (HJ) boys to fly the new fighter. He suggested that they be trained on the wooden two-seat glider version of the He 162 and then proceed directly to fly the fighter.47 This idea was also not completely new, as several suggestions were made earlier to establish a Luftwaffe Hitler Youth outfit on the same lines of what the Waffen SS did in mid–1943 with its HJ Division.48 The Rüstungsstab discussed the idea on 5 October, and Keller agreed to take the responsibility for pilot training, using training gliders manufactured by NSFK workshops to train cadets from the HJ manpower reservoir. By that time the NSFK had already gained some experience in high-speed pilot training, as it performed basic training of Me 163 rocket fighter pilots, which required glider flying skills.49 According to at least two sources the NSFK established an HJ training detachment titled Jagdfliegernachwuchs für Sonderzwecke (Fighter pilot cadets for special purposes) at Trebbin, south of Berlin, and some engineless He 162s were flown there by instructors from late March 1945. One of the gliders was test-flown at Trebbin on 4 April by wellknown test pilot Hanna Reitsch. However, no HJ pilot ever finished the training course, let alone flew an He 162.50 It seems, though, that although Göring received Saur’s memo, the idea was never officially adopted. The mere fact that the grand boss of Germany’s aircraft production came up with such an absurd idea reflects the irrational thinking prevailing in the German administrative and technical leadership in these desperate days. In late October the He 162 project was well underway. Initial design work was completed and manufacture of the first two prototypes progressed despite problems with delivery of components from outside suppliers—especially from the cabinetmakers.51 Manufacture of the prototypes started in Vienna and in its “Languste” underground dispersal plant on 25 October. By mid–November 1944, some 116 skilled German workers and 257 inmates worked on the first planes.52 While the prototypes were nearing completion, Heinkel began to manufacture the initial batch of 30 pre-production aircraft. The first prototype (designated He 162V1) was rolled out on 2 December 1944. Test pilot Gotthold Peter first flew the prototype from the Schwechat airfield on 6 December 1944—only three months after the conception of the project and four days ahead of schedule. The flight had to be cut short after 12 minutes because a wooden main undercarriage door broke away in mid-flight. After the landing, Heinkel technicians found out that the mishap was the result of defective bonding of the glued joint.53 This minor structural failure was a bad omen, reminiscent of the problems that had doomed the Ta 154. Four days later the prototype crashed in Schwechat during its second flight in front of numerous important guests, including Kessler and his staff, and local Nazi leaders. One of the wings disintegrated during a high-speed low-level pass and the aircraft plunged into the ground, killing Peter. Francke, who was responsible for the flight, was later criticized by a coworker for turning the plane’s second flight into a flight demonstration and for allowing it to take place in bad weather conditions.54 Subsequent investigation, which was aided enormously by a film of the accident shot by military cameraman Lieutenant Helmut Kudicke,55 revealed that the cause was another and more serious case of defective glue bonding of the wooden component which disintegrated under the stress of maneuvering at high speed.56 This faulty bonding looked like a symptom of a wider problem in the wood part manufacture. Further investigations suggested that particularly the lamination of the wood parts in “Languste” suffered from the high humidity in the underground galleries.57 Consequently Kessler ordered to strengthen the wooden wing and to exercise stricter quality control at the cabinetmaking firms “so that even a crazy guy will not be able to cause some damage.”58 Heinkel also imposed severe flight restrictions until the problem could be solved.59 Problems with the wooden components persisted, and in early January 1945 Heinkel even asked his design team to consider replacing the wooden wing with a metal wing.60 Despite the early misfortune, the project continued. Carl Francke, Heinkel’s technical director and an experienced test pilot, flew the second prototype (V2) for the first time on 22 December 1944. Later that same day Paul Bader, a test pilot from the Luftwaffe’s Rechlin Test Center, flew the same plane again. He was generally satisfied, but pointed at some instability.61 The development program moved on at full speed, and as customary in the German aviation industry, by mid–November 1944 there were already a dozen further developments of the basic airframe on the drawing board, including two with different jet engines, one with a V-tail and the two aforementioned two-seat trainer versions.62 The V-tail version was considered to be an important development because of the enhanced stability and controllability it theoretically offered. Heinkel asked DFS in late September to test this tail on his old He 280V8 jet fighter prototype. Due to different difficulties DFS could not run the test until April 1945, and by that time the original twin tailfin configuration was considered satisfactory enough.63 All the flight-testing of the new fighter was carried out in Vienna. Earlier, new prototypes were usually taken after the first flights to one of the Luftwaffe’s test centers— usually Rechlin—and were test-flown there. At that time of the war most flight-testing was carried out at the firms’ airfields in order to save time and fuel. Test personnel from Rechlin were usually sent to observe flight-testing and to try new planes for themselves.64 At the beginning of January 1945 the Luftwaffe ordered the establishment of a special operational trials unit for the aircraft. Erprobungskommando 162 was expected to start operations at the Lärz airbase by February.65 However, the program kept suffering setbacks, and as a result the trial unit was never established. During advanced flight-testing of more prototypes the plane displayed poor flying characteristics. Prominent among them were general instability—particularly on the lateral axis, ineffective rudders, excessive side slip and leaking wing fuel tanks. The aerodynamic difficulties dictated additional wind tunnel tests in the research facilities of the DVL in Berlin in January 1945. Heinkel also consulted Dr. Alexander Lippisch, one of Germany’s top aerodynamicists and designers. Further tests were conducted in the water tunnels of the Hamburgische Schiffbau Versuchsanstalt in Hamburg—a shipping research center.66 These tests provided valuable data about the airflow around the airframe, and as a result the wings and tail assembly were redesigned. One of the most important changes was the addition of new wing tips canted down at a 45° angle, as suggested by Lippisch, and accordingly named “Lippisch Ears.”67 Another problem that was difficult to solve was the leaking of the wing fuel tanks. The wooden wing was of the “wet” type. In such wing no separate fuel tanks were installed within the wing structure. Instead, the wing itself was a fuel tank. It was extremely difficult to make the wood skinning of the wing completely leak-free and the problem was solved only at the beginning of March after some improvement of the skinning lamination process.68 The redesign and more problems that surfaced during flight-testing of the prototypes delayed the delivery of the first aircraft to the Luftwaffe by more than three months.