Tu-4 BULL - Development

In March 1946, A.N.Tupolev reported to Minister M. Khrunichev: "the quest for the aircraft B-4, the Design Bureau of plant No. 156 March 5 (10 days before the set date) completed the delivery of a complete set of working drawings of aircraft factory No. 22 and, thus, gave ... the necessary technical documentation for production deployment. B-4." At the same time it was decided the factory No. 22 in Kazan the first series of twenty cars.

By the autumn of 1947, serial production of the Tu-4 (now named) was established at plant No. 18 in kuybyshev, where already by November 18, 1947 year 15 aircraft were produced. After a detour to factory airfields, they were surrendered and were brought to the customer. Training of flight crews engaged test pilot V.P.Maroon, who has mastered flying on a B-29 during his service in the far East. In January 1948, the commanders of two Tu-4 - Maroon and Ponomarenko - made the first long-range flight, having gone without landing 5000 km from Moscow to Turkestan, where they dropped 2000 kg of bombs.

Not all went smoothly with these machines. So, in September 16, 1947, the last flight for program production tests at the third serial Tu-4 had an fire engine. Eliminating the fire, despite the measures taken, failed and Captain A.G.Vasilchenko ordered the crew to leave the aircrft, leaving only engineer I.I.Filizona on board the. He did it in time, because the burning engine broke off and the plane was forced to land in the town of Kolomna. The plane was burnt and it was decided not to rebuild. The second case occurred a month later. The fifth aicraft on landing collapsed part of the right-wing flaps in the chassis. The third case occurred in October 1947, the aircraft during the flight no. 13 from Kazan to Moscow. It caught fire on three engines. The crew was able to make an emergency landing, but the two crew members were killed.

There were difficulties with production and development aircraft. For example, the guns, the first two aircraft armament testing decided they were unsafe to operate. Both aircraft the customer did not accept because of the large number of defects, which were met, however, and on subsequent machines.

The complete aircraft had to have imported products. So, Al-73TK used foreign magnetos, alternators, starters, and lamps. Because of the lack of domestic sources, it used overseas radios, SCR-27N, landing lights, aviagorizonty and sextants. Some sources tell about the raids to the West of special agents to purchase there on military sales giant tires, wheels and brakes from the B-29.

According to the April 1948, government regulation, state tests began on three Tu-4 and lasted nearly eight months. Pilots-verifiers A.Kabanov, P.V. Stefanovskiy, M.Nûhtikov, A.Kochetkov, A.Proshakov, and others tested the machines. Tests were carried out by officers. As leading pilots was appointed Colonel of the Vaganova-chief-pilot's Commander, Lieutenant Colonel Gromov DA-Chief test pilot of the military takeover, Ponomarenko was the Inspector of piloting technique one of the divisions. Co-pilots were Soldatkin, test pilot of the military takeover, Voronin, Deputy Commander of the AE and Senior Lieutenant-Commander Toropov.

Tests showed that the alleged Tupolev normal (47850 kg) and handling (54430 kg) weight flight did not comply with the Government decision. Flight characteristics obtained from the engines at nominal regime were lower than specified. Maximum speed at sea level did not exceed 420 km/h and at an altitude of 9500 m-550 km/h service ceiling on the engines of exemplars corresponding to 0.75 from the nominal capacity reached only 9500 m. The maximum range with 1500 kg technical bomb was 5200 km, and with 7120 kg bombs and fuel 9100 kg - 3060 km.

After removing 65 of 82 of detected defects, on new state tests industry filed for 10 aircraft. Modified Tu-4 can be used with normal weight 55000 lbs without any restrictions, except for landing when the weight is not greater than 48000 kg. When flying with a weight of 65000 kg estimated declined 4.05 overload up to 3.56, but that was enough for flights. On planes with new engines Al-73TK 3 series reached a maximum speed at low altitude of 435 km/h and at an altitude of 10250 m — 558 km/h. The service ceiling of Tu-4 reached 11200 m and it was raised there in 58 minutes. With 1500 kg of bombs and fuel load 13500 l range reached 5100 km, and with fuel and l 26700 3000 kg of bombs-6580. However, the 3000 kg bombs of the size required did not exist in the arsenal and were not provided.

In April 1949, the industry developed 20 Tu-4 and in May the Government Commission selected four of them, who have standards, for repeated monitoring of State testing. In accordance with the Government decision of the year 1949 may to be on production aircraft hanger inside the fuselage shortened caliber 3000 kg bombs.

By the end of 1949, when there were already composed more than 300 machines, aircraft production was established at plant No. 23 in Moscow. Just prior to the completion of construction was 1296 aircraft, including factory No. 22 built 655 (1948-1952), factory No. 18-481 (1949-1953), factory No. 23-160 aircraft (1950-1952).