Soviet aircraft manufacturing is a matter of pride not only for those who have already disappeared from the map of the Soviet Union, but also for modern engineers who are the heirs of their illustrious predecessors. This article will discuss a unique aircraft. This is the Yak-36 aircraft, the characteristics of which will be considered in detail.
Background
The idea of creating a unique aircraft, which would have vertical take-off and landing, appeared long before the creation of the aircraft and was realized in the form of a helicopter. The production of an airplane with properties similar to a helicopter dragged on for many years. The main reason for the delay in the creation of such a vessel was that the specific gravity of all power plants in it would be too large, and the power would be small. As a result, things got off the ground only in the 1940s, when turbojet engines saw the light . From engineering to bench testing to the creation of a real airplane, a period of two decades has passed.
The authors
One of the pioneers in this area of aircraft construction was an engineer named Shulikov, who in 1947 proposed the use of a special rotary nozzle of a turbojet engine (TRD), which was later installed on the Yak-36 aircraft.
A little later, designer Shcherbakov developed the project and began to test a model of an airplane on a flight stand, which took off vertically and did not have a wing, but was equipped with a pair of rotary turbojet engines mounted on the side surfaces of the fuselage. But the lack of a wing caused a storm of indignation in the engineering environment, which put an end to the continuation of this project.
Yakovlev Design Bureau
The most successful team, which was engaged in the creation of vertically taking off planes, was OKB-115, whose leader was the legendary Alexander Sergeyevich Yakovlev. This engineer in 1960 proposed the development of the Yak-104 aircraft. On this aircraft, it was planned to install two forced P19-300 engines, which were to be used as lifting and marching elements. Their thrust was 1600 kgf. The lifting engine was supposed to be one motor. The developers planned that with a flight weight of 2800 kilograms and a fuel reserve of 600 kg, the car was supposed to fly at a top speed of 550 km / h and rise to a height of 10,000 meters. Moreover, the flight range would be equal to 500 kilometers, and its duration would be one hour ten minutes.
Project Yak-V
In April 1961, the Council of Ministers draft was completely prepared on the creation of a single-seat bomber aircraft with a pair of P21-300 engines (each with a thrust of 5000 kgf). This was already the Yak-36 plane. The ship was supposed to have a flight speed of 1100-1200 km / h at an altitude of 1000 meters. At the same time, the weight during take-off should not be more than 9150 kilograms.
For faster development of the stabilization system and the control system, checking the functionality of the rotary nozzle of the Yak-36 engine, proposals were made to test a prototype bomber with existing P21-300 turbojet engines, in which the thrust index would be 4200 kgf. In parallel, the equipment of the machine was provided with rotary nozzles. This document was published on October 30, 1961.
The development of the Yak-36 aircraft was led by S. G. Mordovin. Engineers were also involved: Sidorov, Pavlov, Bekirbaev, Gorshkov.
The working process
The creation of the new generation aircraft took place at a time when Britain could already boast of a similar Harier aircraft, which was equipped with one turbo engine and two pairs of rotary nozzles. However, Soviet engineers went their own way, slightly different from the west.
Given the purpose of the Yak-36 aircraft and what engines it was equipped with, it is not surprising that jet rudders with tremendous traction were installed in the nose and rear parts of the fuselage of the car. One of them had to be pushed forward on a rather long bar. And all because the task of these rudders was not only to control the control of aircraft in transient modes, but also to ensure perfect balance of the vessel during static hovering. As for the engines themselves, they were mounted on the nose of the aircraft, and the nozzles were placed in the center of gravity of the Yak-36.
Machine Features
The described layout of the aircraft’s power drive led to the necessity of using a bicycle-type chassis with a one-wheel support on the nose and a two-wheel support on the back. The wing supports were retracted in the direction opposite to the direction of flight of the Yak-36, and were located in the fairings. A highly sensitive air pressure receiver with special sensors for glide and attack angles was installed on the right fairing. The very design of the airframe was quite typical for aircraft of those years: the fuselage was semi-monocoque, and the side member was equipped with flaps.
Security
When developing the Yak-36 aircraft, the photo of which is given in the article, the engineers had no idea how the vessel would behave during the flight (it would fall to the side during take-off, or other force majeure circumstances would arise). In this regard, to ensure the safety of the pilot during various emergency situations, the aircraft was provided with a forced ejection device. Also, the aircraft had a full-fledged automatic control system during the flight speed, tending to zero.
Aircraft production and testing
The first four vessels were built at a plant located on Leningradsky Prospekt Moscow. One of these aircraft was used to test the model for strength. In the spring of 1963, tests were carried out on aircraft number 36, aimed at checking the degree of protection of engines against the penetration of the reflected stream of the jet, as well as life tests. For this purpose, the Yak-36 attack aircraft was equipped with two gas shields, one of which was mounted on the nose, and the second in front of the turbo engine nozzles.
The second car with tail number 37 worked exclusively landing and take-off. Initially, the height was half a meter, and a little later, this figure was already 5 meters. In two years, 85 training freezes were completed. June 25, 1963 the ship had an accident: there was a breakdown of the chassis during a vertical landing due to the high slip index.
The third aircraft (tail number 38) helped to check the efficiency of the jet rudders, the autopilot system and the controls located in the cockpit. The developers selected such air flow rates that allowed the aircraft to be stable during hovering and made the car completely controlled by the pilot.
Identified difficulties
As practice has shown, it was most difficult to carry out a vertical landing. The two test pilots had different opinions about the aircraft. So, the pilot Garnayev believed that the landing should be carried out only by helicopter type, that is, the car had to be planted from a great height with the preliminary repayment of the speed. In turn, the pilot Mukhin had a different opinion. He said that in a helicopter the support is provided by the main rotor, while on the Yak-36 this wing at different stages of the flight is guaranteed by the wing and gas jets of the engines. Therefore, it was necessary to take into account the moment of transfer of the lifting force from the wing directly to the power plant. And therefore, the landing had to be calculated by the height indicator, which would correspond to the height of movement in a circle. As a result, it was Mukhin who was right.
Flight testing
Hanging of the Yak-36 aircraft was carried out at a half-meter height above the pit, which was closed by a steel grate. This was done to reduce the interference level of gas jets. However, making sure that the vessel was able to take off vertically, they soon abandoned the grate and switched to a solid underlying surface. And there were problems. At that moment, when the landing gear was torn off from the runway, the plane began to shake violently and it landed sideways. At the same time, the power of the gas rudders was sorely lacking.
To determine the engine thrust, the aircraft had to be fixed on the scales. Designers in their research progressed extremely slowly, almost at a snail's pace. Sometimes it happened that a multi-ton aircraft swayed in the air so that almost did not obey the pilot's commands. It was possible to tame the plane after it turned out to exclude the ingress of a gas stream into the air intake device. This led to the fact that the plane pressed to the ground and became manageable.
First flight
The Yak-36 aircraft, whose history spans more than one decade, first made a full flight on July 27, 1964. However, to raise the ship into the air, Mukhin took off and ran, since no one undertook to predict his behavior in the air. Most likely, it was after this test that the refinement of all three machines took place, which consisted in the installation of two ventral fins on each of them.
Two months later, the first full hang of the aircraft occurred. Mukhin mastered the car so much that he even allowed himself to throw the control stick at that moment of the flight, and the plane crashed in place without any deviations.
Everything went to the fact that it was possible to perform full-fledged flights. However, for this I had to work hard for another year and a half. On February 7, 1966, Mukhin performed a vertical take-off, carried out a flight along a circular path, and sat down in an airplane. March 24, the pilot carried out vertical take-off, circular flight and vertical landing. This day is considered the birthday of a domestic aircraft with the possibility of vertical take-off.
Technical indicators
The aircraft in question had a small payload, and therefore the design bureau developed a modernized model of the Yak-36M, which, after being adopted, received the marking of the Yak-38. The new vessel already had a slightly different layout, which proved itself much better in practice.
The Yak-36 aircraft, the technical characteristics of which are indicated below, became a real breakthrough in domestic aircraft construction. So, its technical data is as follows:
- The length of the vessel is 16.4 m.
- Wingspan - 10 m.
- Machine height - 4.3 m.
- The wing area is 17 square meters. m
- The mass of the empty vessel is 5400 kg.
- Take-off weight - 9400 kg.
- Engine - 2 x turbojet engine R27V-300.
- Unfocused traction - 2 x 5000 kgf.
- The maximum speed at an altitude of 1100 km / h.
- The maximum speed near the ground is 900 km / h.
- Real ceiling - 11000 m.
- Crew - 1 person.
- Weapons - combat load up to 2000 kg. UR air-to-air R-60M, NUR, bombs.
Training model
The Yak-18T aircraft was developed back in 1964. Over the years of its use, it has undergone some changes, and in 2006 the Russian government decided to resume serial production of the Yak-18T (series 36). This aircraft is used for educational purposes for training cadets of flying universities.
The Yak-18T 36th series has the following features:
- An air three-bladed propeller of the AB-803-1-K series is installed on it.
- The dashboard has undergone major changes.
- The range of the real flight was increased and additional tanks of 180 liters each were installed in the amount of two pieces.
- The doors in the cab have been improved.
- The heating system is strengthened (a second air heater is installed).
- The firewall was made of stainless steel.
- The fuel used is Premium-95 gasoline.
This aircraft was exhibited at various international exhibitions of aviation equipment (MAKS-2007 and MAKS-2009).
The regulations established that this aircraft must accidentally work out 3,500 hours or 15,000 landings without any calendar restrictions.