Ilyushin TsKB-26 / TsKB-30 / DB-3 / IL-4
The TsKB-26 long-range bomber prototype forst flew in 1935, a twin-engined metal low-wing monoplane powered by 597kW Gnome-Rhone K14 radials.
Demonstrated by test pilot Vladimir Kokkinaki on May Day 1936, the prototype went on to establish two world altitude records during July 1936.
A second prototype, the TsKB-30 had an enclosed instead of open position for the pilot, Soviet M-85 engines and a metal rear fuselage. The TsKB-30 also broke records and then attracted world interest by flying from Moscow to Canada, where pilot Kokkinaki had to make a wheels up landing on 28 April 1939 after covering a distance of 8000km.
The TsKB-30 entered production in 1937 as the DB-3B (DB being a Soviet contraction denoting long range bomber). Early examples were powered by 571kW M-85 engines, but these were replaced by 716kW M-86s in 1938.
It served widely with the ADD (Long-Range Aviation) and the V-MF (Naval Aviation), remaining operational well into the war with Germany, DB-3s being credited with some of the earliest attacks on Berlin.
The aircraft suffered from a poor defensive armament of single nose, dorsal and ventral 7.62mm guns, and lost heavily during the Winter War against Finland in 1939-40.
The DB-3 served also with the Finnish air arm between 1940 and 1945, five captured aircraft being augmented by six purchased from German war booty supplies. DB-3 production terminated in 1940 with the 1,528th machine.
In 1939 a modified version with lengthened nose and more armour (the DB-3F) appeared, and in 1940, in conformity with changed Russian practice, the designation became IL-4 (denoting the designer, Sergei Ilyushin).
Soon after the German attack on the USSR opened in 1941 it was decided to withdraw IL-4 production to newly opening plants in Siberia, at the same time replacing a large proportion of the metal structure by less strategically critical wood. IL-4s also entered service with Soviet Naval Aviation, and it was a naval manned force of these bombers that first raided Berlin from the east on 8 August 1941. Thereafter the IL-4 paid frequent visits to the German capital and other targets in Eastern Europe. In 1944 production ended, although the IL-4 served until the end of the war and afterwards. Apart from increasing the calibre of its guns and giving it a torpedo carrying ability, the IL-4 remained virtually unchanged between 1941 and 1944.
Well over 5,000 IL-4s were produced between 1937 and 1944, the vast majority in the last three years.
Engine: 2 x M-87B, 708kW
Max take-off weight: 7660 kg / 16887 lb
Loaded weight: 5270 kg / 11618 lb
Wingspan: 21.44 m / 70 ft 4 in
Length: 14.22 m / 46 ft 8 in
Height: 4.19 m / 13 ft 9 in
Wing area: 65.6 sq.m / 706.11 sq ft
Max. speed: 445 km/h / 277 mph
Ceiling: 9700 m / 31800 ft
Range: 3800 km / 2361 miles
Armament: 3 x 7.62mm machine-guns, 2500kg bombs
Engine: 2 x M88B, 810kW
Max take-off weight: 10055 kg / 22168 lb
Empty weight: 5400 kg / 11905 lb
Wingspan: 21.4 m / 70 ft 3 in
Length: 14.8 m / 48 ft 7 in
Height: 4.1 m / 13 ft 5 in
Wing area: 66.7 sq.m / 717.95 sq ft
Max. Speed: 429 km/h / 267 mph
Cruise speed: 340 km/h / 211 mph
Ceiling: 9700 m / 31800 ft
Range w/max.fuel: 3800 km / 2361 miles
Range w/max.payload: 1200 km / 746 miles
Armament: 3-8 machine-guns, 2500kg bombs