The P-3, (a.k.a. LIG-5 (Leningradskii Institoot Grazdahnskovo Vozdooshnovo Flota- Leningrad Institute civil air fleet), was a multi-purpose trainer aircraft designed and built in the USSR from 1936.
In 1930 the LIIPS (- Leningrad institute for sail and communications engineers) formed a UK GVF (- training centre for civil air fleet), in turn the UK GVF formed the NIAI (Naoochno-Issledovatel'skiy Aero-Institoot - scientific test aero-institute) which became the focus of several good design engineers who were given command of individual OKB (Osboye Konstrooktorskoye Byuro – personal design/construction bureau).
The P-3 was designed by Anatolii Georgievich Bedunkovich, an Engineer Colonel, was conceived as a more powerful and faster aircraft similar to the LK-4, able to be produced in several versions to carry out different tasks. The three variants tested were intended for military training of pilots and crewmen. Construction was of wood throughout with some fabric covering. Testing at Leningrad was successfully completed by February 1937 when the aircraft was transferred to NII VVS (Naoochno-Issledovatel'skiy Institoot Voyenno-Vozdooshnykh Seel – scientific test institute of the soviet air force), for further testing, a production order was anticipated but the prototype crashed irreparably, due to pilot error, and no production was authorised.