Heinkel HD 55
The Heinkel HD 55 was a German katapultierfähiges flying boat of the 1930s. It was the first in series at Heinkel built flying boat and was exclusively for the Soviet Navy (WMF ) was developed. There it was under the name of KR- 1 (for Korabelni Raswedtschik, Russian Корабелний разведчик = ship spotters ) are used. HD stands for Heinkel biplane
Development
In order to increase the combat effectiveness of the Russian of the Imperial Navy after the revolution acquired battleships and cruisers, the Soviet leadership to equip them with aircraft catapults and related aircraft decided. However, the domestic aircraft industry had no experience in the construction of seaplanes and their launchers. So you saw himself forced to buy foreign types. Since the aircraft manufacturer Heinkel had in 1927 carried out with the HD 15 trials with a catapult flying boat, said the beginning of 1930 the deputy chief of the Soviet Air Force Yakov Alksnis personally at Ernst Heinkel ago to give the development a copy in the contract. The plane was a local Bristol Jupiter License motor M -22 received, so the drives were not included in the order.
Heinkel based his design on the HD 15 and completed construction in a very short time. For the tests conducted in Germany was a Siemens - Halske engine (370 kW), also installed a Bristol Jupiter license. This was followed by the decrease of the designated as HD 55 prototype and in the accompanying operated with compressed air catapult K- 3 by a Soviet commission. The pilot K. N. Ganulitsch was instructed in the handling. At the same time an order for 20 machines that short time later increased by another 20 took place. Other sources speak of a total of 30 aircraft on order.
The HD 55 was taken to the Soviet Union, where already in March 1930 after the installation of an M -22 testing by the pilot Germitschew began in the port of Leningrad, but because of the not yet ice-free harbor basin with Skifahrwerk. The HD delivered 55/KR-1 were used on ships of the Black Sea Fleet and the Baltic Fleet until 1938. They were replaced by the KOR -1 and KOR -2. From the K -3 catapults only two pieces on the ships Parischskaja Kommuna ( Paris Commune ) and Krasny Kavkaz ( Red Caucasus) were purchased and installed. They proved to be not very reliable, so the on-board aircraft to the start had to be watered more often with a crane.
The KR-1 was the first used by the Soviet Navy to airborne aircraft. With him and the K-3 valuable experience for developing their own seaplanes and aircraft catapults were collected.
Technical structure
The KR-1 was built in Gemischtbauweise tense, zweiholmiger biplane. The fuselage had a two-stage Kiel and consisted entirely of wood. Among the covered with fabric wings were two auxiliary float. In winter, a Skifahrwerk could be installed. The motor was splashproof on a frame above the cockpit. The elevator was braced.
The catapult K-3 was operated with compressed air stored in steel cylinders which have accelerated mounted on a trolley on an airplane speed of 110 up to 130 km / hr.