Thursday, May 24, 2012

AircraftTu-124


In aviation, it is often when once found, the layout is used repeatedly to create a more modern aircraft, or other purposes. So it was in 1920 when the Tupolev by linear scaling scheme developed TB-1 TB 3, TB 4, TB-6 and STA-20. And if the TB-3 satisfy the requirements of the early 1930s, and served until 1945, then the next giant step in the design turned out to be regressive in the air and were either in single units or projects.

Beaten track went. Tupolev and thirty years later. This time, he reduced the geometry of the Tu-104, and retaining all its flaws, has created a short-haul passenger Tu-124. It should be noted that, initially, the OKB-156 under the code "124" was worked long "low-flying bomber", then the index passed to civilian car, finally securing the Design Bureau index of all passenger aircraft.

Development of a new liner with bypass turbojet engines D-20P (EDO PA Soloviev) takeoff thrust of 5500 kgf started in accordance with the decision of the Council of Ministers of the USSR of July 18, 1958. The plane, according to the technical specifications, intended for the "connection with the republican capital regional and major industrial centers and links between them, as well as for flights on international routes ...".

Government document provided to the liner was carrying 36-40 passengers (5000 kg payload) at a distance of 1350-1500 km at a cruising speed of 750-900 km / h for the navigation of fuel left for 30 minutes of flight. Maximum speed wondered at least 950 km / h, and the length of run and run - within 800 meters Crew - 4 people. Envisaged the possibility of conversion "of the aircraft in the airfield conditions for the transport of troops, the wounded and the various loads. Document also instructed to complete the finishing of the D-20P with a thrust of 5800 kg.

It should be noted that three years ago, a machine similar applications developed by OKB-240 under the leadership of Ilyushin. IL-16 with four turbojet engines AM-9 was carrying 40 passengers at a distance of 1600 km. But he has remained on paper.

Use the D-20P with low temperature and velocity of exhaust gases reduced the noise level, but only slightly. But before the engine is installed on the passenger liner, it was flight-tested on the Tu-4LL, and then, in accordance with the decision of the Council of Ministers on the establishment of the Tu-124, finishing in three flying laboratory Tu-110B. Improving the reliability of turbojet and promoted the use of the individual units in a helicopter turboshaft engine A-25.

A more rigid structure of the wing, according to developers, helped to reduce jolting aircraft when passing through areas with high air turbulence (turbulence).

According to the LL Selyakov at the selected zoom factor 0, 8 produces a fuselage diameter of 2 and 8 pm However, since the time of copying the B-29 tooling production plants producing the Tu-4 was calculated under the fuselage diameter of 2, 9 m , which was for the Tu-124. But where is the Tu-4 is unclear, because the planes were produced at different factories. Most likely not assemble salon. The total volume of pressurized fuselage compartments was 122 m3, while in the passenger cabin had less than half - 50, 15 cu. m

March 24, 1960 the crew of the first test pilot AD Kalina Bureau made its first flight on the Tu-124 (USSR-45000). Following this, the crew of a test pilot GK NII VVS AK Starikov state tests began to ship. It should be noted that by this time in "Aeroflot", including the Research Institute of Civil Aviation had enough pilots with experience flying on a jet plane, but apparently, the old ties with the military did their job. Moreover, with the inception of the Tu-124 provided to military applications.

In the same year at the Kharkov Aviation Plant (then called 135) released the first production car modeled on the state tests have held experimental Tu-124. At the State Research Institute of Aviation Tu-124 with tail number 45 004 passed in November 1961. Lead test pilot assigned N. Malinin. Looking ahead, we note that the first production car in June 1963rd finalized and handed over to the defense.

As with all aircraft, the Tu-124 had a mass of operational constraints. In particular, in normal use his speed should not exceed more than 0, 78, the speed of sound, although the reduction was allowed during an emergency flight to the number of "M" to 0, 86. Limiting the height of the flight was limited to 11,200 m

Apparently mindful of the failures of the Tu-104, a new car experienced a failure in a tailspin. It was found that the plane, like its predecessor, features closer to the minimum allowable velocity was not, but kept the effectiveness of all controls.Upon reaching the air speed of 210 km / h at altitudes of 11-12 km, where there are anomalies with very high turbulence of the air, began shaking while stalling the wing. 
In that case, the method worked out of the dangerous machine output mode.

According to the test pilots, Tu-124 had a large stock of the longitudinal and lateral stability than the Tu-104. At the same stock of elevators and their effectiveness were also higher. Note that the alignment of the plane could be varied in the range of 21 to 30% of the mean aerodynamic chord.

A year later, after the completion of operational testing, held once in five cars, 20 October began regular flights with passengers, first on the route Moscow - Tallinn, next month in Ulyanovsk, and in December in Vilnius. During the first three years of production the 135th factory built 35 passenger cars.

Since April 1964 the flight of Tu-124 en route from Moscow to Warsaw began international shipping. So Tu-124 in conjunction with the An-24 began rapidly to displace from the airline passenger IL-14.

The first production cars were distinguished by an elongated nose, limited the visibility when landing. The third production aircraft nose section shortened to 500 mm and a few dropped down. Their production began with the eleventh car. Due to the heavy weight of the insulation of the first production Tu-124 greater than 300 kg of the settlement, and the lack of margin of the wing led to a gross weight limit of the first 16 aircraft at 34,500 pounds and maximum values 
​​of the velocity head.Subsequently, during the repair of these machines installed reinforced console.

In the summer of 1971, I happened to be aboard the Tu-124. The first thing that caught my eye, this is a threshold in the cabin, stumbling on which it was not worth the labor. As in the Tu-104, it appeared from the wing center section, which, according to the ideas I had to hide under the floor. Pretty close, but comfortable cockpit was match for the passenger compartment, but more on comfort, when man of medium height knees rest against the front seat, however.

There was no auxiliary power unit (APU), whose mission is air conditioning in a pressurized cabin on the ground. If in winter you can warm the interior by means of ground ovens, then had to sweat in the summer, waiting for takeoff. APU came later, but on other aircraft. Instead of centralized refueling fuel was poured into separate groups of tanks, which delayed the re-training machines to crash.

Getting into the modern passenger jet, it is impossible not to notice the emergency exits. In the Tu-124 did not. The only door there was at the top of the fuselage, although provided for emergency escape and through the cargo hatch in the tail. Passengers lucky. To my knowledge, the escape hatch only once been used for its intended purpose. In one of the flights on the route Tallinn - Leningrad during the approach did not come out the front landing gear.

Having decided at an emergency landing, the crew poured the fuel, but not calculated. Before the airport was far away and had to sit on the water surface of the Neva. Passengers and crew successfully evacuated, after which the ship sank. I must say, on an airplane provided for the installation of an inflatable emergency ladders, but they are known to have appeared later on the Tu-124 were not used.

Another feature of the ship, preserved in the Tu-134 had two entrance doors on the left side. Front of them was used for entry and exit of passengers on the ladder, but to the rear, with good intentions, does not roll up the ladder and it was actually used as a utility with a ladder.

Wing aircraft with looking like a Tu-104 was different mechanization. Besides the traditional slotted flap, incidentally ineffective on its outer surface located air brakes - spoilers, deflected by an angle 52 only after touching the wheels on the chassis of the runway. There was a landing flap and under the fuselage, but good of him, and indeed from the spoilers, as I understood, was not enough.

Control of the aircraft as the Tu-104 was hand wheel with a hard wired to the handlebars, and ailerons. About any boosters on a passenger plane in those years, Tupolev, and would not hear. The control system on all three channels are included servos autopilot AP-6E. Release Management landing flap and flaps electromechanical, interceptors - hydraulic.

In general, all on the Tu-124 was quite conservative, even the landing gear was calculated to operate from unpaved airfields. To shorten the path used by the drag chute area of 
​​40 square meters. m, placed in a container in the rear fuselage.

Life-support system, except for air conditioning, oxygen equipment consisted of the crew (for the prevention of fatigue) and passengers (in case of the illness). In addition, there were portable oxygen equipment of the crew to move in the depressurised cabin for passengers who feel the lack of oxygen.

To ensure flight safety in icing conditions the front edge of the wing and the air intake TRD shell warmed by hot air, taken from the fourth stage of the compressor engines. The front edges of the fin and stabilizer mounted electro-icing device.Windscreens cockpit and the navigator had a molecular film heating, and the glass canopy pilots installed mechanical wiper motor type "janitors." In case of failure of one engine plane could continue to rise and fly at altitudes of 5000 m Tu-124 had a standard radio equipment. Note only radar sight RLV-NAM, acting on the principle of radar PSBN-MA and used to solve navigation problems.

The crew consisted of two pilots, navigator and flight attendants.

Right at the same time the pilot was a radio operator, navigator - the operator of the radar sighting device. At the beginning of operation of the flight engineer was a member of the crew temporarily. Starting from the car 1350303, provided the installation in wartime landing and sanitary equipment.

On the aerodynamic perfection of the liner shown by the following figures. In cruise flight, for example, at an altitude of 10,000 m and the speed of 780 km / h, corresponding to the number of M = 0, 725 aircraft had a glide 12, 5, and the run-up to the flaps to 20 degrees.

The first modification was the navigator training and the Tu-124SH, whose production has begun on a 135-m plant in 1962. The aircraft radar sighting was replaced by the radar, "Rubin-1A" with the two indicators. In the lounge equipped with a few jobs for students-navigators. Starting from 1963, were installed on the aircraft wing racks DB-360 (between the engine nacelles and landing gear) with lifting devices, bombs caliber from 50 to 250 kg. One holder permitted suspension of up to four bombs weighing 1,000 kg.

Due to rebuild shops on the aircraft, designated Tu-124V, it was possible to increase the number of passenger seats to 56 and thereby improve the efficiency of the liner. On this machine the three shops have one, by removing unnecessary tables and installing lightweight chairs with backs, folding tables staffed. Range with payload of 5000 kg has remained the same 1500 km. Three of these machines in 1963 and 1964 respectively set to Czechoslovakia, where they were exploited by "HSA" and the same in the GDR and China. They can be found in India. Two of the aircraft was sold to Iraq. Serial production of this modification was completed in the spring of 1966.

In addition to the machines of "Aeroflot", produced and cabin options for both the USSR and abroad. Three of these aircraft were operated in India. Built and vans, convertible cars. In particular, the Tu-124K was intended for the carriage of cargo and 36 passengers, and second, the Tu-124K-2 - 22 passengers.

In 1963, the plant 135 released three experimental Tu-124B engines from the D-20P-125, characterized by increased take-off thrust up to 5800 kg and reduced fuel consumption. At the same time, they also had a larger diameter, which required revision nacelles. Apparently, the advantages of the new power plant, "drowned" in the increased drag and weight of the power plant. In "Aeroflot" Tu-124B is not received. In addition, 29 July 1963rd made the first flight of Tu-124A with the same engines (USSR-45075), which became the prototype of the Tu-134. Advantages of the new machine were obvious, and further develop the not very successful Tu-124 had no meaning.

During the period from 1962 to 1965, the first plant 135 produced 165 Tu-124 of all modifications. More than half of them operated under the banner of "Aeroflot". The rest of the Air Force in the USSR and abroad. And in the Soviet Air Force operated not only for the educational training of pilots and navigators, but the passenger Tu-124 (for example, in the 8th Adon). In the second half of 1970, in accordance with the decision of the XXV Congress of the CPSU, the continued updating of the planned fleet. Fell into the category of obsolete and Tu-124. Of these, as far as I know, crashed only one side of 45 044. It happened December 23, 1973-th. Served longer than all the Tu-124SH, copies of which the last was removed from service in the late 1970s and 1980s.





Aircraft performance
Equipage
3 persons.
Cruising speed 
840 km/h
Range with maximum payload
1600 km.
Maximum range with a load of 3000 kg. 
2100 km.
The maximum takeoff weight
38000 kg.
Maximum payload 
6000 kg.
Number of passengers 
56 persons
Type
D-20P
Traction motors 
2*5400 kg.

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