Shortly after the Nazi party came to power in Germany in 1933 a require-ment was issued for an up-to-date single-seat monoplane successor to the He 51 and Arado Ar 68 biplanes. Heinkel's designers chose the comparatively easy task of refining the He 70 configuration to produce the He 112, which had an open cockpit, all-metal fuselage and elliptical wings. The prototype VI (D-IADO) was powered by a 518kW / 695-hp Rolls-Royce Kestrel V engine and flew for the first time in late summer 1935. It was flown to Travernfinde for official tests in October that year, compet-ing with the Arado Ar 80, Focke-Wulf Fw 159 and Messerschmitt Bf 109.
Both it and Messerschmitt's Bf 109 received orders for 10 aircraft.
November and December 1935 saw the appearance of second and third prototypes (V2 and V3), both later having the wingspan reduced by 1 m (3 ft 3 in) and powered by 447kW / 600-hp Junkers Jumo 210C engines. The V3 was armed with two 7.9-mm (0.311-in) MG 17 guns mounted over the nose, and had an enclosed cockpit.
The He 112 V4, V5, V6 and V8 were built as prototypes for the projected He 112A production series.
The fourth prototype, with a new elliptical wing, was evaluated operationally with the Legion Condor in Spain in 1936, and was shown at the July 1937 Zurich International Flying Meeting.
The V8 was tried with a 1000-hp DB 600Aa powerplant, but no A-series production order was received although the aircraft was well liked by its pilots.
The proposed He 112A production aircraft was not adopted by the Luftwaffe, which received the Bf 109 instead, but work continued on the structurally-redesigned He 112B, the 507kW Jumo 210Ea-powered production prototype which flew in July 1937.
A batch of 43 He 112B-0s was, however, produced, based on the much-modified V7 and V9 prototypes. Armament comprised two MG 17s, which were now fitted in the fuselage sides, plus two wing-mounted 20-mm (0.79-in) MG FF cannon. Powerplant was the 680-hp Junkers Jumo 210Ea 12-cylinder liquid-cooled engine. In spring 1938 Japanese naval aviation had also received 12 of 30 He 112B-0s ordered in the spring of 1938 but pilots were not enthusiastic and the aircraft were used mainly for ground instruction; their Japanese designation was A7He1. The next 12 were impressed for Luftwaffe use, although 11 of these and the final six were supplied later to the Spanish Nationalist air force in November 1938. Deliveries of 12 to the Luftwaffe commenced in mid-1938 for service trials, and later that year 17 flew with the rebel Spanish Nationalist forces in Spain. Fifteen survived the civil war to serve with the new Spanish air force in Morocco.
Hungary acquired the V9 and three B-Is for evaluation in the spring of 1939, and the only other buyer for the He 112 was Romania, which ordered 24 (13 13-0s and 11 B-1s) , the order being completed in September 1939. They served briefly during the Second World War, the only He 112s to do so.
In the fighter-bomber role the aircraft could be fitted with underwing racks to carry six 10-kg (22-lb) antipersonnel bombs. Two further prototypes, the V10 and V11 with DB 601Aa and Junkers Jumo 210G engines respectively, were produced in the hope of encouraging further export orders, but none were forthcoming and Heinkel decided to use its workforce on producing types acceptable to the Luftwaffe.
At least one was tested with a 2200 lb thrust liquid-fuel rocket motor in the tail.
Span: 9.1 m (29 ft 10.25 in)
Length: 9.3 m (30 ft 6 in)
Gross weight: 2250 kg (4960 lb)
Maximum speed: 510 km/h (317 mph)
Armament: 2 x 20mm MG FF cannon, 2 x 7.92mm MG 17 machine-guns
Engine: 1 x Jumo 210G, 490kW
Max take-off weight: 2250 kg / 4960 lb
Empty weight: 1850 kg / 4079 lb
Wingspan: 9.1 m / 29 ft 10 in
Length: 9.3 m / 30 ft 6 in
Height: 3.9 m / 12 ft 10 in
Wing area: 17.0 sq.m / 182.99 sq ft
Max. speed: 510 km/h / 317 mph
Cruise speed: 475 km/h / 295 mph
Ceiling: 9500 m / 31150 ft
Range w/max.fuel: 950 km / 590 miles
Range w/max.payload; 850 km / 528 miles
Armament: Armament: 2 x 20mm MG FF cannon, 2 x 7.92mm MG 17 machine-guns