This was the initial concept for a heavily armed fighter with Klimov M-100 engines.

AG-1 - 20mm ShVAK cannon
AG-2 - 37mm Sh-37 cannon
AG-3 - .30 cal ShKAS machine gun

History:
In early 1936, Shpitalny sent a documento the secretary of the STO before the SNK USSR comrade G. D. Basilievich in which he requested permission to construct a new heavy fighter model in the Factory No.22. This document was accompanied by variants with Klimov M-100 and Mikulin M-34FRN engines . Conceptual ideas were signed by Locev (drawings), Sigayev (chief of the brigade) and Polikarpov (builder). The designs were also signed by Shpitalny.

This model was presented as a fully metallic low-wing monoplane and twin-engine power plant, with excellent aerodynamic forms. On both sides of the fuselage were located the two 37mm guns with a total reserve of 100 missiles. The magazines with 5 projectiles each were placed in an elevator powered by an electrical system.

In the forward area, in front of the pilot, was a fixed 20mm ShVAK cannon with 100 - 200 projectiles and belt feed. In the cabin of the gunner to defend the rear hemisphere was located a ShKAS machine gun with 540 projectiles. This machine gun was installed on a movable suit that guaranteed the shot to the right or the left. The cockpit of the gunner had a glazed cover that could be raised on the fuselage, which guaranteed a shot angle of 65º upwards, 15º downwards and 45º towards the sides by the horizontal.

The idea of ??this type of plane did not find at that moment the necessary support within the military circles.