The Polikarpov P-2 was a unsuccessful transitional trainer largely based on the Moiseenko P-1 (2U-B3). This earlier aircraft was designed by V L Moiseenko, a designer working at GAZ No.1 in Moscow, in response to a February 1925 specification for a training aircraft to be used between basic training and conversion training onto combat aircraft.
The P-1 was a two-seat single-bay biplane. Its main distinguishing feature was the use of a single diagonal bracing strut than ran from the lower wing root to the upper wing instead of more traditional bracing wires.
The prototype P-1 was completed early in 1926 and underwent state trials between September 1926 and February 1927. A small batch of ten production aircraft was then ordered, but at this point Polikarpov appears on the scene (at this time he was also working at GAZ No.1). He designed a version of the same aircraft, but using the M-6 engine - a licence built version of the 300hp water-cooled Hispano-Suiza 8Fb engine. The nose was redesigned to hold the new engine, but the rest of the aircraft was very similar to the P-1, with the same staggered wings, single-bay design and diagonal bracing strut, tail and cockpit arrangement.
On 14 April 1927 a mock-up of the new P-2 was inspected, and it was decided that this design showed more potential than the BMW-powered P-1. The batch of ten P-1s was cancelled and two prototype P-2s were built instead. This was followed on 12 August 1927 by an order for sixty production aircraft.
The first prototype underwent factory tests in June 1928, and state acceptance trials between 25 June and 9 August. Production of the first thirty series aircraft was then approved, and began at Zavod 23 in Leningrad. These aircraft were completed in 1929-30, and may have been the only production aircraft completed, although some sources state that 55 were built (one source of confusion may be that the Red Air Force accepted 25 P-2s in 1931, possibly from this original batch of 30).
The second prototype was completed in August 1928 and tests lasted until May 1929. A number of problems with the aircraft were uncovered at this stage - the wings on one prototype collapsed on 10 August 1929 in flight, and a second was lost after it entered an unrecoverable spin. More tests in 1930 produced a generally negative report - the P-2 was ruled out of its secondary reconnaissance role, and only approved as a trainer after its faults had been fixed.
The P-2 saw little use at the trainings schools. Ten had been issued by the start of 1932, two were with operational units and the rest were in storage. By the end of 1932 all of the surviving aircraft were in storage, and they didn't return to service. Instead the Polikarpov R-1 was used as a transitional trainer.
Wing span: 10.47m/ 34.34ft
Length: 7.85m/ 25.7f
Empty Weight: 1,064kg/ 2,345lb
Loaded Weight: 1,424kg/ 3,140lb
Max Speed: 220km/h/ 136mph
Service Ceiling: 5,330m/ 17,500ft