He 119 ✙
The He 119 V-4 is one of the more unusual pre-war combat aircraft conceived by the Gunther brothers under the leadership of Hertel. This revolutionary aircraft, relying on aerodynamics, had, in addition to pure forms, an unusual power plant, consisting of two twin engines located in the fuselage and working on one propeller. The cooling system was evaporative. The concept of the aircraft was more than original, and Ernst Heinkel, anticipating serious opposition from the officials of the Technical Department, carried out work on the creation of the aircraft in complete secrecy. The belief in the project was such that Heinkel laid down eight experimental aircraft at once. At Heinkel's request, Daimler-Benz paired two 12-cylinder liquid-cooled DB-601 engines side by side so that the inner row of cylinders was almost vertical, the engines were “upside down” (the cylinder heads were at the bottom). A common gearbox provided the connection between the two crankshafts. This twin was placed near the center of gravity, just behind the main spar. A closed elongated shaft passed through the cabin and ended with a four-blade variable pitch propeller.
The entire nose of the fuselage has been glazed, providing pilots with excellent visibility. The pilots sat on either side of the engine shaft. To reduce the size of the dashboard, some of the instruments were placed on the outer casing of the engine shaft passing through the cab.
The fuselage had a monocoque all-metal structure with a working skin. Directly behind the main spar was a bomb bay that could hold three 250kg bombs, and behind it was a radio operator's cabin and a compartment for photographic equipment. An inverted gull wing had one spar and riveted metal sheathing. In the center section there was an evaporative cooling system for twin DB-601 engines. A system of pipes diverted steam under the wing surface, and the condensed water was fed back to the cooling circuit by a centrifugal pump. The large propeller required the installation of unusually high landing gear struts, the problem of such a landing gear retraction was solved by using telescopic shock absorbers on the struts, which were compressed during the retraction process.
The aircraft was to be used as an unarmed bomber or reconnaissance aircraft, whose safety was ensured by extremely high flight characteristics, like the English Mosquito, created two years later. Work proceeded very quickly, and in the summer of 1937, the weather vane-captain Gerhard Nitschke lifted it on its maiden flight. The evaporative cooling system was supplemented with a radiator under the fuselage, as ground tests showed insufficient efficiency of the first, especially during takeoff and climb. Despite this, the aircraft's aerodynamics were excellent. The aircraft at an altitude of 4500m reached a speed of 562 km / h, and at 6000m - 526 km / h.
Contrary to expectations, the Technical Department, although impressed by the aircraft's flight data, considered it impossible to accept an "unarmed" bomber and reconnaissance aircraft, believing that faster interceptors would appear by the time the series was launched. Heinkel was asked to put defensive weapons on the plane. The aircraft received the official designation He 119, and the twin DB-601 engines - DB-606.
As a result, the first prototype aircraft was hastily equipped with improvised shooting installations, despite the active resistance of Siegfried Gunther (Walter Gunther had died by that time, which immediately gave a 15% drop in speed.
The second prototype He 119-V2 (D-ASKR), equipped with a DB-606A-1 engine with a takeoff power of 2350 hp. and 2200 hp. at an altitude of 3700 m, received a real bomb bay. The first flight took place in early September 1937, after which it was submitted for official testing in Rechlin as an "unarmed" bomber. The main difference between the He 119-V2 was a new radiator - semi-retractable, smoother than on the first aircraft. This immediately had its effect - the maximum speed increased at an altitude of 4500m to 580km / h and 550km / h at an altitude of 6000m. The takeoff weight was 8100 kg, and with 2425 liters of fuel He 119-V2 could fly near the ground at a speed of 410 km / h 2650 km and 2800 km at an altitude of 4500 m at a speed of 485 km / h.
He 119-V4 (D-AUTE) flew earlier than VЗ (D-ADPQ), a two-float seaplane designed for reconnaissance and action on ships. Both aircraft received a new elliptical wing, with a span of 15.9 m and an area of 50 m & # 178. This new wing was designed by Siegfried when the V1 was still in assembly and the results of his tests were not yet known. The first flight of the V4 took place in October 1937.
He 119-VЗ, completed in the first weeks of 1938, differed only in the installation of a two-float landing gear, an increased keel and ventral ridge. The single-run floats were of an all-metal construction. One MG-15 machine gun was installed on the fuselage. The installation of cameras was provided on the lower glazed hatch. The aircraft was successfully tested in Travemunde, but the Technical Department did not like it very much.
The four remaining aircraft were completed in the spring and early 1938. The He 119-V5 and V6 were the prototypes of the Series A reconnaissance plane, and the V7 and V8 were the prototypes of the Series B bomber. All four aircraft were three-seater, armed with just one MG-15 machine gun in the upper position. In the bomb bay V7 and V8, it was possible to hang 16 × 50kg or Z × 250kg bombs, or in an overload 1 × 500kg + 2 × 250kg bombs. The aircraft were tested in Rechlin in the summer of 1938. After returning to Mariene, the Japanese showed great interest in them.
The Japanese were impressed by the speed and range, and especially the power plant. Later, a license was acquired along with two He 119-V7 and V8 aircraft. The plans for the serial production of the He 119 in Japan were never implemented, but some of its solutions were used in the design of the experimental R2Y1 Keiyun reconnaissance aircraft with a twin engine in Yokosuka. The prototype aircraft that remained in Germany were mainly used for testing the DB-606 and DB-610 engine pairs.