Ilyushin DB-3

Ilyushin DB-3

Company type	Aircraft
Industry	Aerospace
Founded	1935
Founder	Sergey Ilyushin
Products	Bomber aircraft

Template:Infobox aircraft

The Ilyushin DB-3—with "DB" representing Dalniy Bombardirovshchik (Russian: Дальний бомбардировщик), meaning "long-range bomber"—was a Soviet bomber aircraft utilized during World War II. This twin-engine, low-wing monoplane completed its maiden flight in 1935. Production totaled 1,528 units. The DB-3 served as the foundation for the subsequent Ilyushin Il-4, initially known as the DB-3F.

Design and development

The origin of the DB-3 traces back to the BB-2, Sergey Ilyushin's unsuccessful contender against the Tupolev SB. Rather than discarding the BB-2 project, Ilyushin adapted its design into a long-range bomber, once again competing with a Tupolev model—the DB-2—to fulfill demanding specifications. These required delivering a bombload of 1,000 kg (2,200 lb) over 3,000 km (1,900 mi) at a minimum speed of 350 km/h (220 mph). The redesign incorporated the radial Gnome-Rhône Mistral Major 14Kdrs engine, which the Soviets licensed in 1934 as the M-85, leading to prototype development under the designation TsKB-26 in that same year.

Serving primarily as a concept demonstrator rather than a full bomber prototype, the TsKB-26 featured wooden fuselage and tail surfaces combined with metal wings and control surfaces to accelerate construction. Its first flight occurred in summer 1935, revealing excellent stability, ease of control, and notable agility—it performed the Soviet Union's first twin-engine aircraft loop maneuver. Additionally, it achieved six world records within its category, mostly related to payload capacity at altitude and speed over a closed circuit exceeding 5,000 km (3,100 mi).

The definitive DB-3 prototype, designated TsKB-30, was finalized by March 1936. This model incorporated several enhancements compared to the TsKB-26: an all-metal airframe, an elongated nose section, an aft-sliding canopy with a fixed windshield, and upgraded engine cowlings. After successfully completing State acceptance trials, it entered production in August 1936 as the DB-3, though some sources label this initial production batch as DB-3S (seriynyy, meaning series-produced).

Manufacturing the DB-3 presented significant challenges due to Ilyushin’s efforts to minimize weight by pushing contemporary construction techniques to their limits. For instance, each wing spar consisted of four riveted components requiring rigorous X-ray inspection for weld integrity—a process prone to frequent failures. Furthermore, riveting small-diameter internal tubing proved labor-intensive and complex.

The bomb bay was engineered to carry ten 100 kg (220 lb) FAB-100 bombs internally; however, external racks allowed heavier ordnance up to 2,500 kg (5,500 lb) for shorter sorties. Defensive weaponry for the three-man crew included three 7.62 mm (0.3 in) ShKAS machine guns: one positioned in the nose operated by the bombardier-navigator and two covering rearward arcs. The rear gunner managed both the SU dorsal turret gun and an LU ventral hatch gun.

Flight testing of a second pre-production unit between May and October 1937 indicated slightly reduced performance compared to the TsKB-30 prototype but still surpassed original specifications by a wide margin. It reached speeds up to 390 km/h (240 mph) at 5,000 m (16,000 ft), could transport 500 kg (1,100 lb) bombs over 4,000 km (2,500 mi), and deliver 1,000 kg (2,200 lb) loads across 3,100 km (1,900 mi). By comparison, the then-current Heinkel He 111B was approximately −10 -20 slower and carried only 750 kg (1,650 lb) bombs up to 1,660 kilometres (1,030 mi), or 1,500 kilograms (3,300 lb) for ranges near 910. This performance arguably positioned it as one of the finest twin-engine bombers worldwide upon its 1937 introduction. That year saw production of 45 units at Factory No. 39 in Moscow and No. 18 in Voronezh, with induction into service with the Soviet Air Forces (VVS).

In 1938, production models transitioned from the M-85 engine to an upgraded M-86 rated at 950 horsepower (710 kW) during takeoff. Aircraft equipped with this powerplant are correctly referred to as DB-3 2M-86 but are sometimes called DB-3A following a planned three-stage enhancement program. Additional minor modifications were implemented throughout that year. Factory No. 126 in Komsomolsk-on-Amur also commenced manufacturing DB-3s during this period.

Between 1938 and 1939, incremental adoption of the Tumansky M-87A engine occurred alongside VISh-3 Controllable pitch propellers replacing fixed-pitch units on production lines. Although sharing identical takeoff horsepower with the M-86, the M-87 delivered greater power at elevated altitudes. The subsequent M-87B variant further enhanced high-altitude output and entered service between 1939 and 1940; these versions were designated DB-3B as part of the upgrade program's second phase. The final production runs in 1940 incorporated the Tumansky M-88 engine generating 1,100 at takeoff power, boosting maximum speed to 429 at an altitude of 6,800.

Nomenclature

There is considerable inconsistency among sources, including original Soviet records, regarding the names typically attributed to the DB-3. According to the official Soviet designation system, aircraft roles were identified by a two-letter code, followed by a model number within that category, then the number of engines, and finally the engine type. For instance, SB 2M-100A translates to a twin-engine fast bomber, first model in its series, powered by M-100A engines. Informal shorter abbreviations were also in use; however, their application varies between references. For example, the VVS strength report dated June 1, 1941, lists both DB-3A and DB-3 variants, with the DB-3A being more common. Yet, this contrasts with Gordon’s account where DB-3A refers to one of the earliest DB-3 models. Additionally, mentions of DB-3B versions are notably absent.

Operational history

File:Экипаж и авиамеханики готовят к вылету советский дальний бомбардировщик ДБ-3Б.jpg

DB-3B in service with the Baltic Fleet

In 1939, thirty DB-3 aircraft were delivered to the Republic of China Air Force amid the Second Sino-Japanese War. These bombers engaged extensively against Japanese forces around Wuhan, operating mainly from Sichuan bases and primarily utilized by the 8th Group until they were superseded by B-24 Liberators in 1943.

On June 14, 1940, two DB-3s were involved in downing the neutral Finnish civilian Junkers Ju 52 transport plane Kaleva.

During the Winter War, Finnish forces captured five DB-3Ms that had made forced landings. Subsequently, in 1941, Finland acquired an additional six DB-3Ms and four DB-3F/Il-4s from German surplus inventories.

On the night spanning August 7–8, 1941, fifteen DB-3T torpedo bombers from the Baltic Fleet executed the first Soviet bombing raid on Berlin. Following this, starting August 11, VVS-operated DB-3Fs resumed strategic bombing missions.

Achievements

• Between June 27 and 28, 1938, pilot Vladimir Kokkinaki and navigator Alexander Bryandinsky completed a nonstop flight covering 7,580 kilometers (6,850 kilometers direct distance) from Moscow to the Far East (Spassk-Dalny, Primorsky Krai) aboard the TsKB-30 "Moscow".

• On April 28, 1939, pilot Vladimir Kokkinaki alongside navigator Mikhail Gordienko accomplished the inaugural nonstop transatlantic flight from Moscow to North America’s East Coast (Miscou Island, New Brunswick, Canada) using the TsKB-30 "Moscow". This journey spanned nearly 8,000 km over 22 hours and 56 minutes at an average velocity of 348 km/h.

• On July 27, 1940, an all-female crew consisting of lead pilot Mariya Nesterenko, co-pilot Maria Mikhalyova, and navigator Nina Rusakova undertook a nonstop flight on the route from Khabarovsk to Lviv aboard the TsKB-30N-2 "Ukraina", covering approximately 7,000 km within 22.5 hours.

Variants

TsKB-26

Conceptual prototype for initial testing

TsKB-30

First functional prototype, later altered by removing armaments to pursue long-distance record flights under the name "Moskva". It completed a flight from Moscow to Spassk-Dalny (7,580 km (4,710 mi)) in 24 hours and 36 minutes, maintaining an average velocity of 307 km/h (191 mph) mainly at an altitude of 7,000 m (23,000 ft), piloted by Vladimir Kokkinaki and A. M. Berdyanskij. Subsequently, it flew from Moscow to Miscou Island (New Brunswick, Canada) in 22 hours and 56 minutes, covering 8,000 km (5,000 mi) at an average speed of 348 km/h (216 mph) with Kokkinaki and Mikhail Gordienko at the controls.

DB-3 2M-85

Initial production variant

DB-3 2M-86 (DB-3A)

Upgraded with M-86 engines and minor adjustments

DB-3 2M-87A (DB-3B)

Equipped with improved Tumansky M-87A engines

DB-3T (TsKB-53)

Torpedo bomber developed in 1938, powered by either M-86 or M-87 engines, armed with 45-36-AN or 45-36-AV torpedoes.

DB-3TP (TsKB-51)

Seaplane torpedo bomber prototype from 1938; did not enter production.

DB-3M

Significant upgrade featuring two M-87B or M-88 powerplants.

DB-3F

Replaced the DB-3 between 1940 and 1944, later known as the Il-4.

TsKB-54

Escort aircraft ("air cruiser") designed in 1938 but not adopted for service.

TsKB-56

A larger model from 1940 with a redesigned configuration including a higher wing and twin-tail, powered by two AM-37 engines. Development ceased after two prototypes in favor of the Yer-2.

DB-4

The production name for the TsKB-56, which never advanced beyond prototype stage.

Il-4

The DB-3F was renamed Il-4 in 1942.

Il-6

A long-range bomber variant powered either by two Charomskiy ACh-30 diesel engines or two M-90 radial engines.

Operators

File:Ilyushin DB-3M.jpg

DB-3M bearing Finnish markings

Hungary

Hungarian Air Force - operated limited numbers during the 1939 conflict between Czechoslovakia and Hungary (Slovak-Hungarian War)

Template:Flagcountry

• Chinese Nationalist Air Force

Template:FIN

• Finnish Air Force
  • Lentolaivue 46
  • Lentolaivue 48

Template:Country data Nazi Germany

• Luftwaffe

Template:USSR

• Soviet Air Force
• Soviet Naval Aviation

Survivors

The sole surviving DB-3 is exhibited at the Central Air Force Museum located in Monino, near Moscow, Russia. This aircraft was discovered in the taiga approximately 120 km from Komsomolsk-on-Amur. Recovery took place in September 1988, after which it was transported to the Irkutsk Aircraft Industrial Association (IAIA) facility aboard an Ilyushin Il-76 cargo plane. Following more than a year of restoration work, it was delivered to Monino via an Antonov An-22. On December 22, 1989, IAIA representatives led by V.P. Zelenkov formally handed over the DB-3 to museum personnel.

It is important to distinguish this aircraft from the Ilyushin Il-4 (serial number 17404) displayed within the Victory Park collection at the Central Museum of the Great Patriotic War in Moscow.

Specifications (DB-3B, late production)

File:Ilyushin DB-3 3-view line drawing.svg

Three-view illustration of the Ilyushin DB-3

Bibliography

• Template:Aviation.ru

External links

• Collection of DB-3 and Il-4 images on Aviation.net