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The Henschel Hs 132 was a World War II dive bomber and interceptor aircraft of the German Luftwaffe that never saw service. The unorthodox design featured a top-mounted BMW 003 jet engine (identical in terms of make and position to the powerplant used by the Heinkel He 162) and the pilot in a prone position. The Soviet Army occupied the factory just as the Hs 132 V1 was nearing flight testing, the V2 and V3 being 80% and 75% completed.
There had been interest in the idea of a prone pilot for combat aircraft to reduce the effect of g-forces during maneuvering. Several aircraft had already experimented with this layout for various reasons, the Horten IIIf had a prone pilot, but this was primarily to reduce drag in this high-performance glider,[1] while the DFS 228 reconnaissance glider also used a prone pilot to make it easier to seal its pressurized cabin. It was not until the Berlin B9 was built specifically to test this arrangement for improved g-load that any serious effort toward development could be carried out.
Starting in early 1943, the Berlin B9 twin-piston engined experimental aircraft demonstrated that it was indeed possible for a pilot to fly the aircraft lying down, and that it did improve his ability to handle high loads. The pilot had an extremely restricted field of view upward or to the rear that made it suitable only for certain roles, including bombers or fighters or interceptors with a major speed advantage over their opposition.

Based on this research, several late-war German designs followed the B9's lead and used a prone pilot. Better g-load performance was not the only reason, however, as this layout also reduced the frontal area of the aircraft. This was a serious concern for interceptors attacking the USAAF's B-17 Flying Fortress, as calculations showed that the chance of being hit by its defensive guns was largely a function of frontal area.

The genesis for the Hs 132 was an 18 February 1943 specification published by the German Air Ministry (RLM) calling for a single-seat shipping attack aircraft to counter an expected invasion of Europe. A piston-engined aircraft was called for at the time, but the performance requirements led to a switch to jet power.[2] Henschel submitted their design for RLM approval in April/May 1944, by which point they had already started wind tunnel testing the basic layout. The aircraft that emerged had a roughly cigar-shaped fuselage with short-span mid-set wings and a horizontal stabilizer with considerable dihedral ending in twin rounded-front vertical stabilizers.

The BMW 003 engine was mounted on the back of the aircraft above the wing, likely to make servicing easier due to the low ground height of the aircraft that put the engine roughly shoulder-height. The sharply dihedraled 'butterfly'-like twin rudder arrangement kept the tail surfaces clear of the jet efflux. The cockpit was completely faired into the fuselage contour, with a rounded clear nose-cone on the front of the aircraft. Behind this was the actual "window," a large armored-glass plate located some distance behind the extreme nose; the glazing extended almost to the wing root. The design in terms of engine mounting and tailplane bore a very strong resemblance to the contemporary Volksjäger ("people's fighter") design competition winner, the Heinkel He 162 Spatz (sparrow). The basic A model carried one 500 kg (1,100 lb) bomb; it had no other armament. It was to begin its attack in a shallow dive outside the ships' range of fire, and after reaching a speed of 910 km/h (570 mph; 490 kn), the pilot would "toss" the bomb at the target using a simple computerized sight, and then climb back out of range. The aircraft was designed to withstand 12 g during pullout. The computerized bombsight was not delivered in time to be fitted to the aircraft.

Several other versions of the basic airframe were proposed as well. The Hs 132B used the Junkers Jumo 004 engine in place of the BMW 003, and added two 20 mm  MG 151/20 cannons. The HS 132C was a more extensively modified version intended for bomber interception, featuring the larger Heinkel HeS 011 engine, two 20 mm  151/20s and two 30 mm  MK 103 or MK 108 cannons. The HeS 011, intended to power a wide variety of new and existing Luftwaffe aircraft (an example of the latter being the proposed D and P series of the Arado Ar 234 jet bomber), was still in the pre-production phase when the war ended. It was hoped that by the time the HS 132B became available, the Panzerblitz anti-tank missile would be in production and available for use. The Hs 132D included a new wing of increased span. A contract for six prototypes was approved in May 1944, and construction was begun in March 1945. Hs 132V1 was scheduled to have its first flight in June 1945, but the completed wings and fuselage were never mated, and Soviet forces captured the intact fuselage in May 1945 while the wings were never moved from their factory in France.

Variants
Hs 132A Dive bomber BMW 003 turbojet engine, 1 × 500 kg (1,100 lb) bomb
Hs 132B Dive bomber/Anti-tank plane Jumo 004 turbojet engine, 1 × 500 kg (1,102 lb) bomb, 2 × 20 mm MG 151 cannon, and/or six or eight Panzerblitz anti-tank rockets
Hs 132C Dive bomber
He S 011 turbojet engine, 1 × 500 kg (1,100 lb) bomb, 2 × 20 mm MG 151 cannon and 2 × 30 mm (1.2 in) MK 103 cannon
Hs 132D Increased wingspan variant

On 18 February 1943, the Reichsluftfahrtministerium (RLM – the German Aviation Ministry) released a specification that called for a single-seat shipping attack aircraft to counter an expected Allied invasion of Europe. A piston-engined aircraft was called for at the time, however, the performance requirements motivated the switch to jet power instead.[5] Henschel opted to produce a response to the specification; the design team favoured the high speeds offered by turbojet propulsion as it was felt that survivability, and therefore viability, of the prospective aircraft would be bolstered by using its high speeds to evade interception by Allied defences. Furthermore, as a consequence of these high speed dive attacks, the aircraft would be subject to high g-forces when pulling out; thus, the resulting aircraft was designed to withstand 12 g . To enable the pilot to better withstand such g-forces, it was deemed essential for the pilot to by in the prone position.

Several other factors were taken into consideration during the design phase. As Germany's position declined sharply during the latter portion of the war, there were shortages of both key materials and skill labourers. Accordingly, the aircraft was intentionally designed to minimise its use of strategic materials and to be as simplistic as possible. The structure was not only designed to be simple but also relatively easy to maintain. The BMW 003 engine that powered the aircraft was mounted on the back of the fuselage above the wing and was positioned at roughly shoulder-height as a result of the low ground height of the aircraft. While this placement of the engine was suboptimal in terms of intake performance, incurring increased drag at high speeds due to interference from the engine-fuselage fairing junctions, the design team were aware that the Heinkel He 162, the winners of the contemporary Volksjäger ("people's fighter") design competition, had a similar engine layout and thus were encouraged as to its viability.

The Hs 132 had a roughly cigar-shaped fuselage with short-span mid-set wings and a retractable nosewheel undercarriage.[4] The horizontal stabilizer possessed considerable dihedral ending in twin rounded-front vertical stabilizers; this 'butterfly'-like twin rudder arrangement kept the tail surfaces clear of the jet efflux. The cockpit was completely faired into the fuselage contour along with a rounded clear nosecone on the front of the aircraft. Directly behind was the actual "window," a large armored-glass plate located some distance behind the extreme nose; the glazing extended almost to the wing root.[9] Every flight control surface was fitted with trim tabs. Due to the intended shallowness of the aircraft's dive attack, there were no dive brakes fitted. Despite the similarity of appearance to the He 162, the Hs 132 was intended to perform dive-bombing and ground attack missions rather that fighter duties. In terms of its construction, the airframe made extensive use of non-strategic materials, notably in the wings, which were of wooden construction. The basic Hs 132A carried a single 500 kg  bomb and lacked any other armament. It was to begin its attack in a shallow dive outside the ships' range of fire, and after reaching a speed of 910 km/h , the pilot would "toss" the bomb at the target using a simple computerized sight, and then climb back out of range. This computerized bombsight was not delivered in time to be fitted to the aircraft.

During April or May 1944, Henschel submitted their proposal to the RLM, by which point wind tunnel testing of the basic layout had already commenced. A contract for six prototypes was approved in May 1944. Construction of three prototypes commenced at the company's Schönefeld facility during March 1945. Hs 132 V1 was scheduled to have its first flight in June 1945, however, advancing Soviet forces captured it along with the other two incomplete prototypes during May 1945. Allegedly, while the wings and fuselage of He 132 V1 had been completed, they were never mated and the wings had never been transferred from their factory outside of Dresden.

Several other versions of the basic airframe were proposed by Henschel. The Hs 132B was to have been powered by a single Junkers Jumo 004 engine in place of the BMW 003; it also would have added a pair of 20 mm MG 151/20 cannons. The HS 132C was a more extensively modified version that was intended for bomber interception; it featured the larger Heinkel HeS 011 engine, two 20 mm  151/20s and two 30 mm  MK 103 or MK 108 cannons.The HeS 011, intended to power a wide variety of new and existing Luftwaffe aircraft (an example of the latter being the proposed D and P series of the Arado Ar 234 jet bomber), was still in the pre-production phase when the conflict ended. It was hoped that by the time the HS 132B became available, the Panzerblitz anti-tank missile would be in production and available for use. The Hs 132D included a new wing of increased span.