[ATTACH]766164[/ATTACH]RKIIGA-74 "Experiment"
also known as the "Lodka-Samolyeta" (Boat-Airplane)
Arguably the best known of all RKIIGA aircraft projects, the RKIIGA-74 was started in 1972 by a small group of students, including Yu. Pribylsky, A. Shveigert, and V. Yagnyuk. The group was led by F. R. Mukhamedov (who had already defended his PhD thesis), and engineer R. V. Shchavinsky. Actually, some of the ideas for the RKIIGA-74 originated in an earlier diploma project for a light amphibious flying boat, defended successfully in 1967 by student V. Z. Zeitlin.
The RKIIGA-74 was a two-seater seaplane, the design of which was based on the Progress boat and elements of the KAI-12 Primorets glider (strutted wing and tail unit). Students O. Baryshev, V. Pikalov, and A. Lovtsov joined in the final stages, and active assistance was also provided by the institute's teachers V. F. Bukharov, the research institute's engineer V. Ya. Biryukov, and teacher V. Z. Zeitlin (who had designed the earlier 1967 project).
[ATTACH]766167[/ATTACH]The motorboat was subjected to maximum "lightening" and aerodynamic "refining". Some of the units and parts intended for water-motor operation (floorboards, benches, brackets, etc.) were removed from the boat. However, the frames to which the motor tail boom were attached were reinforced. The windshield was shifted back, and its angle of inclination was increased, which, together with the installation of a fairing on the transom of the boat, made it possible to significantly reduce its aerodynamic resistance. The rear part of the boat's cockpit was decked with a duralumin sheet. Under it, in the middle part of the boat, a 90-liter gas tank and an accumulator were installed, and the oil tank and engine oil system units were located in the nacelle fairing.
[ATTACH]766163[/ATTACH]The boat was equipped with dual controls (two steering wheels and two pairs of pedals), and a dashboard with flight, navigation and engine control instruments. The cockpit was open and the seats were arranged in a row, which allowed the right or left pilot to perform the pilot's duties alternately and use the RKIIGA-74 as a training machine. The flying boat had a takeoff weight of 900 kg, a structure weight of 60 kg, a maximum speed of 165 km/h, and a flight range of 900 km. Once again, the engine used was the same Czechoslovak M-332 piston engine rated at 140 hp, fitted with a metal propeller from a production Czechoslovakian aircraft.
[ATTACH]766168[/ATTACH]By the end of the summer of 1974, the construction of the aircraft was completed (hence the designation "-74"), andits ground and water tests began on Lake Baltezers, near Riga. After completing the required modifications, in particular the installation of an overhead redan, the RKIIGA-74 seaplane was prepared for its first flight, which took place on September 17, 1974 with the Captain of the Latvian Civil Aviation Administration, 1st class pilot V. N. Abramov, at the helm, assisted by V. Z. Zeitlin. At an altitude of about 150 m, the plane made several circles over the lake. A. A. Bodyagin, a Doctor of Technical Sciences and Professor of the Department of Aircraft Design at MAI, congratulated the creative team on their first flight. The designers' calculations were fully confirmed. The plane responded well to the controls and was stable in flight. In total, 15 flights were performed during the tests, for a total of about 2 hours.
[ATTACH]766170[/ATTACH]In April 1975, the Komsomolskaya Pravda newspaper sent its special correspondent T. Ilarionova to Riga to tell the whole country about the future engineers who had raised their first plane into the sky and were already thinking about a new one.The RKIIGA-74 boat was named "Experiment" and in the summer of 1976 represented Latvia at the All-Union Exhibition of Scientific and Technical Creativity of Youth, which was held at VDNKh. The USSR Ministry of Higher and Secondary Specialized Education awarded Yu. Pribylsky, V. Yagnyuk, A. Shveigert, O. Baryshev and V. Pikalov, all participants in the construction of the flying boat, with gold medals and a diploma "For the best student scientific work".
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