The Shavrov Sh-2 (later ASh-2)[1] was a 1930s Soviet amphibious sesquiplane flying boat developed from the Sh-1, with a more powerful engine, slightly increased size and amphibious undercarriage. The Sh-2 could carry three people including the crew.
The Shavrov Sh-2 was developed from the Sh-1 flying boat prototype, which had been built in Shavrov's apartment and which first flew on 21 June, 1929. The Sh-2 was a slight enlargement of the Sh-1, with some detail improvements.[2]
The hull was primarily constructed of pine with the keel and longerons being ash, with a 3mm plywood skinning covering 25 frames, of which 4 were watertight bulkheads.[1] The planing bottom was covered with 6mm plywood, and the entire structure was covered in doped fabric.[1] The cockpit seated three, with a pilot and passenger in the front, both with controls, and an additional passenger behind them while cargo or additional fuel could be carried in the nose and under the seats.[1] The wings formed a staggered sesquiplane, and the outer wing panels, which were given 3 degree of dihedral could be folded back along the fuselage.[1] The centre section used the Kol'chugaliminum aluminium alloy and had a dead eye for hoisting onto ships.[1] The small cantilevered lower wing served as attachment for the stabilizing floats. The cruciform tail had horn balanced elevators, while the rudder was slightly enlarged over that of the Sh-1.[1] The undercarriage retracted by rotating forwards and up in an arc until the axle was level with the cockpit coaming, pulled into position with cables and springs.[1] It could also be fitted with skis for winter operations from ice and snow, while some examples had the undercarriage removed, or weren't built with them.[1] During 1950s, more powerful versions of M-11 were fitted, and some examples were modified with enclosed cabins.
The prototype Sh-2, which had been built at Zavod No.23 in Leningrad made its first flight on November 11, 1930.[3] State Acceptance trials were carried out through 1931, and were passed on 9 May, 1932, without problems, having previously passed its trials for Aeroflot, and series production began in 1933, with the first production batch of 270 being built at Zavod No.31 in Taganrog.[3] Production eventually exceeded 700 aircraft, with the last examples being built in small workshops, in 1952.[3] The Sh-2 remained in service until 1964[3] and set a number of unofficial flying boat and seaplanes records.The Sh-2 replaced the obsolete MU-1 floatplane, whose design dated from before World War One, with the Soviet Air Forces.[3] Examples were operated from the SS Chelyuskin, Fyodor Litke and Krasin icebreakers as well as other vessels.[3] One example was used as a glider tug for the Gribovsky G-16 hydrofoil flying boat glider prototype.[3] Aeroflot was not only a major operator of the Sh-2, they also built them in their own workshops, including 30 to 35 in 1941.[3]
On 28 August 1942, the Finns captured two Sh-2s and impressed them into service in the liaison role.[4]