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The Heinkel He 162 Volksjäger (German, "People's Fighter") is a German single-engine, jet-powered fighter aircraft fielded by the Luftwaffe late in World War II. Developed under the Emergency Fighter Program, it was designed and built quickly and made primarily of wood as metals were in very short supply and prioritised for other aircraft. Volksjäger was the Reich Air Ministry's official name for the government design program competition won by the He 162 design. Other names given to the plane include Salamander, which was the codename of its wing-construction program, and Spatz ("Sparrow"), which was the name given to the plane by the Heinkel aviation firm.[1]

The aircraft was notable for its small size.It had a distinctive top-mounted engine which, combined with the aircraft's low landing gear, allowed the engine to be easily accessed for maintenance. This made bailing out of the aircraft without hitting the engine difficult, and the He 162 was the first single-engine aircraft provided with an ejection seat in an operational setting. The small size left little room for fuel, which combined with the inefficient engine resulted in very low endurance - in the order of 20 minutes - and it only had room for two autocannon, making it relatively underarmed for the era.

A series of fatal accidents during testing required a series of refinements that delayed the program. Although production lines were set up and deliveries began in early 1945, the impending defeat of Germany by that time made the effort pointless. Of nearly 1,000 aircraft on the assembly lines, only about 120 were delivered to the airfields and most of those never flew, usually due to shortages of parts, fuel, and pilots. Small numbers were used in development squadrons and these ultimately saw combat in a few cases during April 1945, yet the He 162 also proved to be quite dangerous to its own pilots as its tiny fuel load led to a number of aircraft crashing off field, while additional losses were attributed to structural failure.

Production was still running when the war ended in May 1945. Numerous aircraft were captured by the Allied forces along with ample supplies of parts from the production lines. Eric Brown flew one just after the war and considered it a first-rate aircraft with few vices. Several He 162s have been preserved in museum collections around the world
Heinkel had carried out some design work of a new twin-engine fighter with one engine placed on top of the aircraft and another under the nose, the highest point on the bottom of the fuselage. For the single-engine development, he removed the lower engine and repositioned the remaining upper engine just aft of the cockpit and centered directly over the wing's center section. This arrangement simplified the overall balance of the aircraft, while also placing the engine in a convenient point for removal as it could be removed upward with a small crane. The need for a crane to be present at every airfield that the aircraft would operate from was a point of contention of the aircraft from Heinkel's rivals.

One consequence of the aircraft's basic configuration was that the jet exhaust would pass directly over the upper rear fuselage and the tail area. For this reason, the tail was constructed with two small vertical stabilizers positioned to either side of the exhaust's path, and the horizontal elevator mounted below it. The horizontal section had considerable dihedral at 14º, raising the vertical stabilizers inline with the wing.

The aircraft's relatively compact wing was mounted relatively high on the fuselage and was attached using four bolts.The leading edge was straight while the trailing edge had a significant forward sweep. It was not possible to remove the wing without first removing the engine, an arrangement that would have hindered routine maintenance of the aircraft.The combination of the engine being directly above the pilot and the wings on either side would make a conventional bailout very risky, so the aircraft was designed from the start to feature an ejection seat akin to the one used in the Heinkel He 219 night fighter.

The main landing gear retracted into the fuselage below the wing and were of the tricycle layout. Heinkel had significant previous experience with this layout on earlier designs including the Heinkel He 280,however, this was the first of their designs to use this layout from the start. A small window in the lower cockpit between the rudder pedals allowed the pilot to visually check whether the gear was down. Partly due to the late-war period it was designed within, some of the He 162's landing gear components were "recycled" existing landing gear components from a contemporary German military aircraft to save development time: the main landing gear's oleo struts and wheel/brake units came from the Messerschmitt Bf 109K, as well as the double-acting hydraulic cylinders, one per side, used to raise and lower each maingear leg.

Prototypes
The He 162 V1 first prototype flew within an astoundingly short period of time: the design was chosen on 25 September 1944 and first flew on 6 December, less than 90 days later. This was despite the fact that the factory in Wuppertal making Tego film plywood glue — used in a substantial number of late-war German aviation designs whose airframes and/or major airframe components were meant to be constructed mostly from wood — had been bombed by the Royal Air Force and a replacement had to be quickly substituted, without realizing that the replacement adhesive was highly acidic and would disintegrate the wooden parts it was intended to be fastening.

The first flight of the He 162 V1, by Flugkapitän Gotthold Peter – the first German jet fighter aircraft design to be jet-powered from its maiden flight onward – was fairly successful, but during a high-speed run at 840 km/h , the highly acidic replacement glue attaching the nose gear strut door failed and the pilot was forced to land. Other problems were noted as well, notably a pitch instability and problems with sideslip due to the rudder design. None were considered important enough to hold up the production schedule for even a day. On a second flight on 10 December, again with Peter at the controls, in front of various Nazi officials, the glue again caused a structural failure. This allowed the aileron to separate from the wing, causing the plane to roll over, it broke up in the air and crashed, killing Peter

An investigation into the failure revealed that the wing structure had to be strengthened and some redesign was needed, as the glue bonding required for the wood parts was in many cases defective. However, the schedule was so tight that testing was forced to continue with the current design. Speeds were limited to 500 km/h  when the second prototype flew on 22 December. This time, the stability problems proved to be more serious, and were found to be related to phenomenon known as Dutch roll. While this tendency could be resolved by reducing the dihedral, however, as the He 162 was supposed to enter production within weeks, there was no time to implement major design changes. Instead, a number of small changes were made, such as the addition of lead ballast in the nose to move the centre of gravity towards the front of the aircraft while the tail surfaces were also slightly increased in size.[citation needed] Despite these measures, some figures, such as Alexander Lippisch, declared the flying characteristics of the He 162 to be unsuitable for inexperienced pilots.

The third and fourth prototypes, which used an "M" for "Muster" (model) number instead of "V" for "Versuchs" (experimental) number, as the He 162 M3 and M4, after being fitted with the strengthened wings, flew in mid-January 1945. These versions also included – as possibly the pioneering example of their use on a production-line, military jet aircraft – small, anhedraled aluminium "drooped" wingtips, reportedly designed by Alexander Lippisch and known in German as Lippisch-Ohren ("Lippisch Ears"), in an attempt to cure the stability problems via effectively "decreasing" the main wing panels' marked three degree dihedral angle. Both prototypes were equipped with two 30 mm MK 108 cannon in the He 162 A-1 anti-bomber variant; in testing, the recoil from these guns proved to be too much for the lightweight fuselage to handle, and plans for production turned to the A-2 fighter with two 20 mm MG 151/20 cannon instead while a redesign for added strength started as the A-3. The shift to 20 mm guns was also undertaken because the smaller-calibre weapons would allow a much greater amount of ammunition to be carried.

The He 162 was originally built with the intention of being flown by the Hitler Youth, as the Luftwaffe was fast running out of pilots. However, the aircraft's complexity required more experienced pilots. Both a standard-fuselage length, unarmed BMW 003E-powered two-seat version (with the rear pilot's seat planned to have a ventral access hatch to access the cockpit) and an unpowered two-seat glider version, designated the He 162S (Schulen), were developed for training purposes. Only a small number were built, and even fewer delivered to the sole He 162 Hitler Youth training unit to be activated (in March 1945) at an airbase at Sagan. The unit was in the process of formation when the war ended, and did not begin any training; it is doubtful that more than one or two He 162S gliders ever took to the air.

Various changes had raised the weight over the original 2,000 kg  limit, but even at 2,800 kg , the He 162 was still among the fastest aircraft in the air with a maximum airspeed of 790 km/h  at sea level and 839 km/h at 6,000 m but could reach 890 km/h  at sea level and 905 km/h  at 6,000 m  using short burst extra thrust. The short flight duration of barely 30 minutes was due to only having a single 695-litre  capacity flexible-bladder fuel tank in the fuselage directly under the engine's intake. The original Baubeschreibung document submittal for the He 162 dated mid-October 1944 showed a pair of fuel tanks for the original version of the Spatz's airframe as-designed: a single, smaller capacity 640 litre fuselage main tank in approximately the same location as the later 695 litre tank was placed, with an additional wing centre-section tank just above and behind it, never produced for the production run, of some 325 litres  feeding by gravity into the main fuselage tank. The A-2 version, in some examples (as the one flown by Royal Navy test pilot Captain Eric Brown postwar) had an emplacement of a pair of "impregnated" 180 litre  wing tanks, one built into each inner wing panel, within the first four wing ribs out from the root and between the spars, that fed into the main 695 litre fuselage tank in a similar manner to what the earlier 325 litre center-section tank had been proposed to do; but were themselves ungauged, their exhaustion of fuel only marked when the main fuel gauge began to fall during flight.The production He 162A-2 was armed with a pair of 20mm MG 151/20 cannon.

Multiple facilities were engaged in the production of the He 162, including the assembly lines in Salzburg, the Hinterbrühl, and the Mittelwerk. By April 1945, it had been anticipated that output would reach 1,000 aircraft per month, which was double the rate achieved when the Mittelwerk plant commenced deliveries. Furthermore, the Air Ministry expected that production were rise even beyond this figure in order to produce sufficient fighter coverage

Operational history
During January 1945, the Luftwaffe formed an Erprobungskommando 162 ("Test Unit 162") evaluation group to which the first 46 aircraft were delivered. The group was based at the Luftwaffe main test center, or Erprobungsstelle at Rechlin.

In February, deliveries of the He 162 commenced to its first operational unit, I./JG 1 (1st Group of Jagdgeschwader 1 Oesau — "1st Fighter Wing"), which had previously flown the Focke-Wulf Fw 190A. I./JG 1 was transferred to Parchim, which, at the time, was also a base for the Me 262-equipped Jagdgeschwader 7, some 80 km south-southwest of the Heinkel factory's coastal airfield at "Marienehe" (today known as Rostock-Schmarl, northwest of the Rostock city centre), where the pilots could pick up their new jets and start intensive training beginning in March 1945. This was all happening simultaneously with unrelenting Allied air attacks on the transportation network, aircraft production facilities and petroleum, oil, and lubrication (POL) product-making installations of the Third Reich – these had now begun to also target the Luftwaffe's jet and rocket fighter bases as well. On 6 April, the USAAF bombed the field at Parchim with 134 Boeing B-17 Flying Fortresses, inflicting serious losses and damage to the infrastructure.[61] Two days later, I./JG 1 moved to an airfield at nearby Ludwigslust and, less than a week later, moved again to an airfield at Leck, near the Danish border. On 8 April, II./JG 1 moved to Heinkel's aforementioned Rostock northwestern coastal suburban factory airfield and started converting from Fw 190As to He 162s. III./JG 1 was also scheduled to convert to the He 162, but the Gruppe disbanded on 24 April and its personnel were used to fill in the vacancies in other units.[citation needed]

The He 162 first saw combat in mid-April 1945. On 19 April, Feldwebel Günther Kirchner shot down a Royal Air Force fighter and, although the victory was credited to a flak unit, the British pilot confirmed during interrogation that he had been downed by an He 162.[62][63] The Heinkel and its pilot were both lost that same day as well, having been shot down over Husum[64] by Flying Officer Geoffrey Walkington,[65][66] piloting an RAF Hawker Tempest. Though still in training, I./JG 1 began to score kills in mid-April, but went on to lose 13 He 162s and 10 pilots. Ten of the aircraft were operational losses, caused by flameouts and sporadic structural failures. Only two of the 13 aircraft were actually shot down. The He 162's 30-minute fuel capacity also caused problems, as at least two of JG 1's pilots were killed attempting emergency deadstick landings after exhausting their fuel.

During its exceedingly brief operational service career, the He 162's cartridge-type ejector seat was employed under combat conditions by JG 1's pilots at least four times. Kirchner had been the first to eject when he was attacked on April 19, but he was too low and was killed when his parachute failed to open.The second recorded use was by Lt Rudolf Schmidt on April 20, with Fw. Erwin Steeb ejecting from his He 162 the following day. Finally, Hptm. Paul-Heinrich Dähne attempted to eject from his aircraft on April 24, but was killed when the cockpit canopy failed to detach.

In the last days of April, as the Soviet troops approached, II./JG 1 evacuated from Marienehe and on 2 May joined the I./JG 1 at Leck. On 3 May, all of JG 1's surviving He 162s were restructured into two groups, I. Einsatz ("Combat") and II. Sammel ("Collection"). All JG 1's aircraft were grounded on 5 May, when General Admiral Hans-Georg von Friedeburg signed the surrender of all German armed forces in the Netherlands, Northwest Germany and Denmark. On 6 May, when the British reached their airfields, JG 1 turned their He 162s over to the Allies.[ Numerous aircraft were shipped to the U.S., Britain, France, and the Soviet Union for further evaluation.

Erprobungskommando 162 fighters, which had been passed on to JV 44, an elite jet unit under Adolf Galland a few weeks earlier, were all destroyed by their crews to keep them from falling into Allied hands. Heinkel did not resort to such measures, the company's engineers supplied the Americans with detailed designs for the He 162.

The difficulties experienced by the He 162 are believed to have been primarily a result of its rush into production, rather than any inherent design flaw. One experienced Luftwaffe pilot who flew the He 162 called it a "first-class combat aircraft." Test pilot Eric Brown of the Fleet Air Arm, who flew a record 486 different types of aircraft, said the He 162 had "the lightest and most effective aerodynamically balanced controls" he had experienced. Brown had been warned to treat the rudder with suspicion due to a number of in-flight failures. This warning was passed on by Brown to RAF pilot Flt Lt R A Marks, but was apparently not heeded. On 9 November 1945, during a demonstration flight from RAE Farnborough, one of the fin and rudder assemblies broke off at the start of a low-level roll causing the aircraft to crash into Oudenarde Barracks, Aldershot, killing Marks and a soldier on the ground.

Variants
He 162 A-0 — first ten pre-production aircraft.
He 162 A-1 — armed with two 30 mm (1.18 in) MK 108 cannons with 50 rounds per gun.
He 162 A-2 — armed with two 20 mm MG 151/20 cannons with 120 rounds per gun.
He 162 A-3 — proposed upgrade with reinforced nose mounting twin 30 mm MK 108 cannons.
He 162 A-8 — proposed upgrade with the more powerful Jumo 004D-4 engine of 10.3 kN (2,300 lbf) top thrust levels. Muster (model) prototype airframes M11 and M12's testing revealed a top speed of 885 km/h (550 mph) at sea level at normal thrust and 960 km/h (597 mph) with maximum thrust,[77] close to the Me 163B rocket fighter's top velocity figures.
He 162 B-1 — a proposed follow on planned for 1946, meant to use the Heinkel firm's own, more powerful 12 kN (2,700 lb) thrust Heinkel HeS 011A turbojet, a stretched fuselage to provide more fuel and endurance as well as increased wingspan, with reduced dihedral which allowed the omission of the anhedral wingtip devices. To be armed with twin 30 mm (1.18 in) MK 108s.
The He 162B airframe was also used as the basis for the Miniature Fighter Project design competition powered by one or two "square-intake" Argus As 044 pulsejet engines. The pulsejet, however didn't provide enough thrust for takeoff and neither Heinkel nor the OKL showed much enthusiasm for the project.[78]
He 162C — proposed upgrade featuring the B-series fuselage, Heinkel HeS 011A engine, swept-back, anhedraled outer wing panels forming a gull wing, a new V-tail stabilizing surface assembly, and upward-aimed twin 30 mm (1.18 in) MK 108s as a Schräge Musik weapons fitment,[citation needed] located right behind the cockpit.
He 162D — proposed upgrade with a configuration similar to C-series but a dihedraled forward-swept wing.[63][79]
He 162E — He 162A fitted with the BMW 003R mixed power plant, a BMW 003A turbojet with an integrated BMW 718 liquid-fuel rocket engine — mounted just above the exhaust orifice of the turbojet — for boost power. At least one prototype was built and flight-tested for a short time.
He 162S — two-seat training glider.

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