The Polikarpov DI-2 was a two-seat fighter developed from the single-seat Polikarpov I-3. The only prototype crashed during 1929 ending work on the project.
The I-3 was the first of Polikarpov's designs to enter series production. The I-3 was largely based on the earlier two-seat 2I-1N/ DI-1, with a similar oval-section semi-monocoque wooden fuselage, but with a liquid cooled BMW VI engine replacing the Napier Lion of the earlier two-seater. The I-3 was also a more robust aircraft that its predecessor, with a thicker wooden structure and more longerons and formers.
The DI-2 was very similar to the I-3 but with a longer fuselage. This was achieved by adding an extra frame to the centre of the fuselage. The wingspan and rudder were also expanded. The DI-2 was armed with four 7.62mm machine guns - two fixed forward firing PV-1 guns above the nose and two DA machine guns mounted on a Scarff ring in the observer's position.
The DI-2 made its maiden flight in May 1929. Later in the year it was destroyed after tail plane flutter caused the tail to break off. The test pilot A.V. Chekarev was killed in the crash, which effectively ended the programme (although Polikarpov's arrest in September 1929 probably didn't help).
Engine: BMW VI
Wing span: 38.7ft
Empty Weight: 3,433lb
Loaded Weight: 4,678lb
Max Speed: 159mph
Service Ceiling: 20,670ft
Range: 317 miles
Armament: Two fixed forward firing 7.62mm PV-1 machine guns and two flexibly mounted 7.62mm DA machine guns on Scarff ring