Grigorovich DI-3

The Grigorovich DI-3 (Russian: Григорович ДИ-3), (Dvukhmyestnyi Istrebitel - two-seat fighter), was a prototype two-seat fighter developed in the Soviet Union in the 1930s. It was intended to be a long-range escort fighter developed from the DI-2 with improved range and performance comparable to single-seat fighter aircraft of the time. DI-3 was a single-bay biplane of mixed construction with a twin-rudder tailplane of variable incidence.

DI-3
Role	Fighter
National origin	Soviet Union
Manufacturer	Grigorovich
First flight	August 1931

Although initial tests demonstrated flight characteristics comparable to Polikarpov I-5, the addition of armament and operational equipment caused significant degradation in performance and DI-3 did not enter mass production. The prototype was subsequently fitted with an enclosed cockpit and used as a VIP transport.

Specifications (DI-3)

Data from Istoriia konstruktskii samoletov v SSSR do 1938

General characteristics

• Crew: 2
• Length: 7.8 m (25 ft 7 in)
• Wingspan: 11.8 m (38 ft 9 in)
• Wing area: 30.1 m² (324 sq ft)
• Empty weight: 1,487 kg (3,278 lb)
• Gross weight: 2,122 kg (4,678 lb)
• Powerplant: 1 × BMW VI 7.3z V-12 liquid-cooled piston engine, 545 kW (731 hp)
• Propellers: 2-bladed fixed-pitch propeller

Performance

• Maximum speed: 256 km/h (159 mph, 138 kn)
• Service ceiling: 6,300 m (20,700 ft)
• Time to altitude: 5,000 m (16,000 ft) in 17 minutes 30 seconds
• Wing loading: 70 kg/m² (14 lb/sq ft)
• Power/mass: 0.26 kW/kg (0.16 hp/lb)
  
• Horizontal turn time: 13 sec

Armament