TB-4 (ANT-16) - Design
The general guidance for the project was carried out by AN Tupolev, A. Arkhangelsky led the design of the fuselage, V. Petlyakov - wings, N. Nekrasov - plumage, N. Petrov - chassis, I. Pogossky and E. Pogossky - power plant, I.Tolstykh - Weapons. Large capacious bomb-bay projected K.Sveshnikov and V.Myasishchev. In October 1930, the preliminary aerodynamic calculation for the ANT-16 with the M-35 engines (the design of the monoblock engine based on the M-34) was completed at TsAGI.
The stumbling block for the project for a long time was the choice of the type and number of engines. Since the beginning of the 1930s, the appearance of the M-35 engines was problematic (this motor became reality only by the early 1940s), so we stopped on six smaller engines (four on the wing and two in the fuselage above the fuselage).
True, the four engines were not immediately abandoned. They tried to buy the engines of the Italian firm Isotta-Frascini, then, due to the refusal of the Italians, they switched to six M-34 calculations with a reducer and without a reducer, for the M-27 project engines with a gearbox, for Rolls-Royce engines and BMW engines . Depending on the engines, the ANT-16 was to have a normal flight mass - from 27,000 kg to 31,000 kg (the overload option is 32,000-37,000 kg), the maximum speed at altitude 6,000 m is 242 km / h, the cruising speed is 200-210 km / h .
In January 1931, the UVVS and TsAGI agreed on the composition of defensive weapons, taking into account the crew of twelve people: two artillery units for 20-mm cannons, five rifle units for twin machine guns PV-1. Bomber weapons included bomb deterrents and bombs of a new design, providing accommodation of forty 250-kg bombs or twenty 500-kg bombs inside the fuselage, one 1000-kg or 2000-kg bombs under the fuselage. In December 1931, the UVVS informed TsAGI of new more detailed requirements for the aircraft, providing for the replacement of four M-35 engines with six M-34s and maintaining the basic flight characteristics of the aircraft.
In its aerodynamic design, layout solutions and design, the new heavy bomber was a further development of TB-3, had much in common with it and differed from it in significantly larger geometric dimensions and increased power of the power plant. At the same time, the basic specific parameters characterizing the aircraft remained practically at the same level as in the case of TB-3. The specific load for the wing area for TB-4 was 63.3 kg / m 2 , and the power plant's power was 8.6 kgf / hp. (for TB-3 - 78.3 kg / m 2 and 7.4 kg / hp, respectively).
The wing of TB-4 consisted of a centroplane and two detachable parts. Unlike the ANT-6, the number of spars in the power set of the wing was reduced to three. The spar races are riveted from sheet material. The fuselage was technologically divided into a bow with a removable toe, tail and middle parts. Compared to ANT-6, the step of the wave of corrugation up to 50 mm has increased.
A feature of the fuselage design is the presence of two large bomb bays, each 5 m long and about 2 m wide, located behind the wing center wing. Such large cargo sections in the fuselage were used for the first time in the world practice of aircraft construction.
The tail plumage is similar to ANT-6. Kiel and the stabilizer were connected with each other by braces. Stabilizer with adjustable in flight with the help of an electric motor mounting angle. Height and turn steering wheels had horn compensation. The control of the aircraft is rigid, except for the ailerons.
Chassis wheels with a diameter of 2 m were installed in pairs on a common axis, rather than a tandem, as on ANT-6, and supplied with oil absorption and brakes. In the rear of the fuselage, there was a pneumatic self-orienting wheel. Provision was made for the wheels of fairings - pants.
Power plant - six M-34 engines with a maximum power of 830 hp. (nominal - 750 hp). Four engines - in the wing sock, and two - in a tandem installation on a welded frame over the fuselage. The gasoline was located in six tanks in the detachable parts of the wing and in two centerplanes. The walls of the outer tanks were at the same time the skin of the wing. The total capacity of the fuel system is 8500 liters. The total capacity of the oil system is 2000 liters.
The pulling screws of the wing engines had a diameter of 3.18 m, the pulling screw of the tandem unit was 3.3 m and the pushing screw was 3 m. For the autonomous power supply of airborne aircraft systems, it was first used a power plant driven by an engine with a power of 16 hp. For autonomous power supply of aircraft airborne systems, it was the first in the world to use a power plant driven by an engine - the prototype of the current auxiliary power units (APU).
Guns were introduced into the system of defensive weapons. The proposed scheme of defensive fire was quite effective and practically did not leave "dead" zones, in this ANT-16 was like a forerunner of future "flying fortresses". The guns were placed in the forward and rear wing of the aircraft fuselage units. Machine guns - in the stern of the fuselage behind the tail unit, as well as in special wing towers in the front and rear parts of the wing (two units for firing forward, two for firing back).
On ANT-16 bomb detonators and bomb-throwers of a new design were installed, which could accommodate forty 250-kg bombs or twenty 500-kg bombs inside the fuselage, as well as one 1000-kg or 2000-kg bomb under the fuselage.
The ANT-16 had the necessary instrumentation, an OPB-2 sight for night bombing, a radio receiver, internal telephone communication, and more. Such a complex and large aircraft with a developed defensive armament system demanded an increase in the crew of up to 12 people: two pilots, a navigator, a radio direction finder, a flight mechanic and seven riflemen.
According to the draft design, an experiental TB-4 with six M-34 engines would have a normal flight mass of 31,000 kg (reloading - 37,000 kg), empty weight - 10700 kg, maximum speed at the ground - 208 km / h, cruising speed - 160 km / h, the ceiling is 3400 m, the range is 1600 km. The normal bomb load is 4000 kg, the maximum is -10000 kg. Defensive weapons: two cannon "Oerlikon" caliber 20 mm, ten machine guns YES.
From February to July 1933, the assembly of the machine and finishing works were carried out at the Central airfield. The testing machine was not fully equipped with equipment and weapons. In particular, there were no tower machine-gun wings. The missing mass was filled with bags of sand.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
