DI-8 (ANT-46) - a heavy long-range fighter (in the then terminology - "flying cruiser") was created on the basis of the medium bomber SB (ANT-40).

The all-metal construction of the DI-8 was in many respects similar and was already well developed and brought to acceptable reliability by flight tests, however, with water-cooled motors. Unlike SB, DI-8 was equipped with two dynamo-reactive guns APK-4 of 76.2 mm caliber, which were developed by the Department of Special Works (USR NKTP). Installed in the detachable parts of the wing with the passage of the trunks through the leading edge skin and exhaust pipes with diffusers above the wing flow rib through its upper skin. The ammunition of each gun was 15 shells.

In the center section of the wing at the starboard side of the fuselage, a third firing point was installed - a ShKAS machine gun with a stock of 800 rounds. Differences also affected defensive weapons. In the bow cockpit of the navigator-bombardier, instead of a pair of ShKAS machine guns, one movable ShVAK 12.7 mm heavy machine gun appeared. In the rear fuselage, the weapon remained as on the SB - the upper turret ShKAS on the TUR-9 mobile unit and the lower hatch machine gun of the same system.

In addition, to protect the rear hemisphere, at the edges of the wing-fuselage junction, just above the trailing edge of the center section, embrasures of two stationary ShKAS machine guns were arranged. Firing from them was to be carried out when the enemy fighter entered the tail. Guided by an airplane and targeted with a rear-view periscope, these ShKAS would be a complete surprise to the enemy. When repelling an enemy attack from such a strict angle, effective firing from the turret and hatch installations would be difficult, and the presence of stationary machine guns in the center section would significantly complicate the conditions for an attack from the rear hemisphere.

The composition of the bomber armament has been reduced in comparison with the SB. A vertical bomb bay was left in the center of gravity of the aircraft. The rear fuselage and center sections were not used and were battened down. The total weight of the bombs did not exceed 250 kg, which corresponded to the TTT requirements for a "flying cruiser".

Construction DI-8 - metal, riveted from duralumin. The fuselage was docked in three parts. In the front part, behind the frontal, transparent cap, the navigator's workplace was arranged. He occupied it by climbing the stairs through the lower hatch. The same opening was an emergency one for leaving the aircraft in the air.

The middle part of the fuselage was carried out at the same time with the center section of the wing. It placed the control post of the aircraft inside the cockpit with a sliding canopy back. The longer canopy of the gunner-radio operator moved forward and opened his cockpit, located at the rear of the fuselage, bearing the tail unit.

Armament. 2x76.2mm APK-4 dynamo-reactive cannons (15 rounds each) or 4x20mm ShVAK cannons and one 7.62mm ShKAS machine gun with a stock of 800 rounds ... One movable 12.7 mm ShVAK machine gun. In the tail section of the fuselage there is an upper turret ShKAS on a mobile unit TUR-9 and a lower hatch machine gun of the same system. Bomb load up to 250 kg.

Due to the removal of the dynamo-reactive cannons of the Kurchevsky system from the plan in February 1936, two new versions of offensive weapons were developed for the DI-8bis (ANT-46bis) backup. One of them involved the use of ShVAK rifled cannons (caliber 20 mm), a pair on each side of the wing, in connection with which the DI-8bis received new wing consoles.

The main flight and tactical characteristics of the DI-8bis were outlined above the SB data in order to successfully protect bombers in flight. To do this, it was planned to install promising M-34RNF engines designed by A.A. Mikulin on the long-range fighter in a short time. However, due to the protracted terms of preparation for the delivery of the ANT-46 for state tests, it was removed from the plan as a failure. Analysis of factory tests forced the customers to abandon this "cruiser".

Photo	Description
	Drawing ANT-46bis (DI-8)

• "Flying cruiser" Tupolev / KR Ivanamin Sultanov /
• Stalin's high-speed bombers SB and Ar-2 / Mikhail Maslov /
• The history of aircraft designs in the USSR, 1938-1950. /V.B. Shavrov /