Yak-45 attack aircraft

After conducting a comprehensive analysis of the Vietnam and Middle East wars, it was recognized the need to develop 2 variants of fighters - a light front-line fighter and a fighter of gaining superiority in the air. The competition for the creation of new fighters was announced in 1969. The competition was attended by the OKB Mikoyan and Gurevich, Sukhoi and Yakovlev. In 1972, the competition for LFI projects involved the projects of MiG-29 and Yak-45 fighters. The winner was Mikoyan OKB project.

In 1972, the Moscow factories Zenit, Kulon and Speed presented the customer with the advanced designs of the MiG-29, T-10, Yak-45I and Yak-47 fighters that retained the predecessor's scheme. But unlike their competitors, Yakovlev Design Bureau specialists began to develop two types of fighters - the light Yak-45I and the heavy Yak-47 . The modified Yak-45I was designed to conduct air combat with enemy fighters and destroy its strike aviation mainly at small and medium altitudes at any time of the day and in any weather conditions. The plane could intercept aerial targets and at high altitudes when it was being brought from the ground.

The Draft project of the first Yak-45 variants was completed in July 1970. It began with these words: "In view of the war in the Middle East and in Vietnam, we have worked out the airplane Yak-45 variant of attack aircraft and fighter aircraft. The aircraft is characterized by a large excess of thrust, exceptional vertical maneuverability, which in combination with a small plane dimension, long range and supersonic flight speed at low altitude makes it possible to successfully carry out the combat mission both in the assault, and on fighter operations. Given the similarity of the requirements for flight performance, the ability to mass production of the aircraft, to simplify and reduce the cost of operation, both options have the same design and aerodynamic configuration. the differences lie in the composition of armament, sighting and navigation equipment. "

Yak-45I reflected the concept of a multipurpose aircraft, as it was intended for the destruction of ground targets, including small-sized and mobile. Comparing the calculated data of the Yak-45I and MiG-29, incidentally, made using the integrated circuit, it is evident that with a Yak-45I take-off weight greater than 500 kg, the 1972 sample had a high thrust and a smaller specific load on the wing. This promised the best maneuverability characteristics, which is very important in close combat. In the design documentation it was noted, in particular, that "to ensure air supremacy at all altitudes and along the depth of the front-line zone, Yak-45I fighters should be supplemented by all-weather fighters with sophisticated weapon systems and equipment." In fact, this was the first step on the way to the heavy fighter Yak-47, whose project was presented by the military in 1972.

The Yak-45 would have been powered by two Favorski Type 69 non-vectoring turbofan engines with afterburner. Dervived from the R-28, they were rated at 8,000 kg (17,635 lb) thrust each. The engines would have been positioned ahead of a large delta wing, with an additional large canard foreplane, giving the aircraft an appearance similar to the Saab Viggen.

The Yak-45 was a twin-engine aircraft with normal aerodynamic scheme with bicycle landing gear. The engines were placed on half-span wing, with two main wing spars thattook the form of half-rings, covering the bottom of the motors. This arrangement gave certain advantages. Firstly, such a placement engine significantly increases the survivability of the machine, reducing the likelihood of damage to the two motors simultaneously. Second, it simplifies maintenance, opening the approach to the engines with almost any hand. In addition, questions were solved simply replace the engines. There were and aerodynamic advantages: reduces losses at the inlet of the air intakes and at the nozzle exit.

The frontal air intakes axisymmetric adjustable with an external braking were shell and leaf feeding bypass engines on the ground to coordinate the work of engine and air intakes at low speeds.

The monocoque fuselage type had a circular cross-section with a maximum diameter of 1.2 m base material structure. Aluminum alloys were used in the form of extrusions, forgings and sheets. Structurally and technologically, the fuselage was divided into several compartments. In the front was located the cockpit, radar, niche nose landing gear, equipment compartments. Before cockpit placed the two built-in cannon GS-23, with a total of 400 rounds ammunition. In this case the charging box installed directly in front of the cockpit, thus protecting the front of the pilot. The 2nd and 4th compartments were fuel tanks. The engines were separate, but in emergency situations, the left and right engines can receive fuel from both tanks. In the 3rd compartment was formed by fastening the wing frames, niche was the main landing gear, hydraulic units and air conditioning systems. At the tail section, which carries the tail, placed Jets equipment and the drogue parachute.

The wing profile with a relative thickness of 5% was developed by the influx of the root portion of a sweep angle 79°, and outer a moderate sweep - 25°. At the rear edge of the wing between the fuselage and engine nacelles were mounted retractable flaps, and on the wing the ailerons. In addition, along the front edge of the console has an automatic slats. The wing design was mostly made of aluminum alloys, with extensive use of stamping and chemical milling.

On the Yak-45I it was intended to install a sighting and navigation system from the Pearl Radar Station, coupled with a direction finder and an opto-television sight. The complex provided for semi-automatic control of the aircraft in battle, on the route and landing, as well as the indication of flight parameters on the devices PKP-72, PNP-72 and on the indicator on the windshield. BRLS "Pearls" provided detection and capture of the target, gave target designation to the direction finder, opto-electronic vizir and GOS missiles.

The pilot also had a second target designation channel for the weapon system from the helmet. The information semi-compass, which is part of the director's management system, calculated the autonomous trajectory of landing and provided a semi-automatic flight at a low altitude (up to 200 m) above the terrain with a slope of relief to 10-15 °. The navigation complex provided the location of the aircraft with respect to ground beacons in the polar coordinate system, piloting by drive and broadcast radio stations and radio beacons, as well as issuing information to the ATC system. Connected equipment provided unprotected communication on VHF-DCH-bands ("Zhuravl-10" radio station) and issuance of a response in the system of identification of state equipment (defendant "Ozon").

The complex of defense signaled to the pilot about the irradiation of ground and airborne radars with the issuance of bearing (station "Bereza-L") and protected the aircraft by the creation of responsive-leading active and passive radio interference (the station of active radioactivity "Geran-UFC" in container version) interference (means of emission of dipole and infrared interference were set in the account of the combat load). The built-in control system for electronic equipment provided automated control of aircraft systems and the recording of emergency parameters ("Tester-I" recorder). The total weight of the equipment was 1460 kg.

Two GSh-23 guns of 23 mm caliber were replaced with one gun of the TKB-645 caliber of 30 mm. At the same time the art armament "moved" from the forward part of the fuselage to the cramped compartment and shifted to the starboard side. A box for 200 cartridges was installed directly in front of the front fuselage fuel tank. In addition, under the wing could hang four containers UPK-23 with guns GSh-23. Under the wing, four points of the K-60 close-in air defense K-60 (6 pcs.) Or K-55 (4 pcs.) Or K-13 (4 pcs.) Suspension were provided. To "work on ground targets" the fighter's armament was supplemented with air bombs, NAR and incendiary tanks. The aircraft could carry up to four bombs with a caliber of up to 500 kg, four 20-barrel guns of the 80-mm NAR of the S-8 family (or the five-barrel 122-mm NAR block of the S-13 family or four NR-class S-25s).

All this, according to the developers, made it possible for the light fighter Yak-45I to successfully maneuver an airborne visual battle with enemy fighters and destroy its strike aircraft at small and medium altitudes in the PMU and SMU day and night. In the materials of the project it was said that "the most important factor that ensured the Yak-45I fighter is the superiority in the air, is its greater maneuverability, which is achieved due to a large power-to-weight ratio, relatively low wing load and the availability of effective air brakes."