Russian experimental aircraft on an air cushion AH-14SH

Samples equip the aircraft chassis Hovercraft taken a huge amount of time. In the USSR, such aid was first created in 1939 by engineers of the Central hydrodynamic Institute of Ephraim NI and Nadiradze AD On the training aircraft VT-2 ("plane of Ephraim and Nadiradze" CEN) instead of wheeled landing gear was installed rubber balloon, having fan installation that resembled an inverted bottom up inflatable boat. Fan, who worked 25-strong motorcycle motor, pump air into the chamber (place) inside the ring of the cylinder. SAINT behaved normally, flying the airplane is actually no different from flying on an ordinary plane. In 1940, tests conducted by test pilot Shelest, as it flew A. Chernov A. Yumashev Gromov.

In 1941, the same creators of such a structure has been designed for ball screws Pe-2. Tanks were positioned under the engine nacelles. The plan designers, the air from the cylinders manufactured after take-off, and the cylinders were drawn into the nacelle, where the doors were locked.

The Soviet experimental aircraft on an air cushion AH-14SH

The device functioned properly, plane Pe-2 taxied, but fly it did not come as prevented by the war. The same pattern of the flexible enclosure chassis hovercraft made in the development of experimental An-714 based on a commercial aircraft An-14. In the title number 7 — the seventh Minaviaproma General Administration, which is subordinate to the Kuibyshev chassis design office of aircraft (control I.Berezhnov) to do this job. Air-cushion landing gear consisted of 3 devices weighing 28 pounds, are placed on the attachment points of the landing gear. Each device — carrying system of flexible enclosure in the form of 3 "bagel" and centrifugal rotor having a hydraulic propulsion of engines. Test pilot Vladimir Antonov Design Bureau Kalinin 20.10.1970 for the first time flew the An-714. During the tests, it was found out that the operating pressure of the air is 850 kg/m2 was too high, and the area of the bearing surface on an air cushion landing gear — correspondingly low. Now it is clear that the jet of air at a pressure of 400 kg/m2, can erode the soil medium strength so that its particles flying in all directions, getting into the ball screw assemblies and vozduhopoglotiteli engines. With all of this because of the uneven flow of air through the gap between the ground and flexible fencing of cushion may even lose bearing capacity. For example, it happened in 1975 during a test of US-Canadian XC-8A "Buffalo", which is equipped with the experience in order chassis Hovercraft with the highest operating pressure.

So when the Antonov Design Bureau in 1971 started designing the chassis on an air cushion for the An-14 (it was given the designation of An-14SH), we immediately chose the path of reducing the pressure at the outlet from the flexible enclosure. The structure consisted of an inflatable enclosure with internal toroidal tank spec. tors around the points (4 pairs), through which the air supply. The design automatically created righting moment when tilting the plane. Due to the location of points on spending significant distance from the edge of the flexible enclosure, the presence of several series of protectors, who created a labyrinth seal created resistance expiring air. The result was that the exhaust air had an energy that was less in comparison with the previous schemes of flexible enclosures. Thus, An-14SH pressure about the last tread was 2 times lower than the estimated cushioning, while the XC-8A aircraft, it was about 2 times higher. Flexible enclosure with an area equal to the area of the wing of the An-14, could get out in the spec. container, which reduced the resistance of the air-cushion landing gear in flight. The scheme worked a flexible enclosure for 2-propelled models, weighing 600 pounds, and on the platform with a full-scale air-cushion landing gear, which were the production and cleaning of flexible enclosures. Air to air bag were taken from the turbine TA-6A-1, installed inside the fuselage An-14.

The Soviet experimental aircraft on an air cushion AH-14SH

Initiative equipment "AN" ballscrews personally owned Antonov OK. The work was a group of enthusiasts of 8 people. BM led Kolomijtsev according to the plan approved by the Ministry of Aviation Industry August 20, 1975. On the serial plane An-14 (serial number 500404) in 1980, docked with the landing gear compartment air cushion, which was the model (scale 1:2) the same compartment of the aircraft AN-12. Rolling tests An-14SH was launched in December 1981, and in winter 1983 at the aerodrome flight test facility experimental design bureau airplane performed the first flight of passing at an altitude of 15-20 meters without cleaning ball screw and turbo off. The machine piloted by test pilot and flight engineer Mareeva Lysenko. During the test the An-14SH was more than 700 km on tarmac and gravel runways, with all this gap between the surface and the flexible fencing of about 6-10 mm, chassis systems hovercraft have accumulated 150 hours. As a result, it was revealed many positive features of the proposed scheme on the chassis Hovercraft, among which is satisfactory Putney stability in crosswinds least 12 m / s and the effective operation of the braking system, which keeps the plane on the ground in the different modes of the engine, including the take-off. In its own report, the pilot Lysenko emphasized that "the stability of the chassis on the runway at hovering in place or when jogging and taxiing at speeds up to 100 km / h is good. Manoeuvrable aircraft during taxiing and jogging excellent, but, asks certain skills. " In connection with numerous interruptions for maintenance and revision of the flexible enclosure tests lasted right up to April 1986, but the cleaning of air-cushion landing gear in flight and did not produce.

The Soviet experimental aircraft on an air cushion AH-14SH

In 1985, experiments were conducted to reduce the flow of air along the lines of contact and enclose the supporting surface (excess air through a special air duct discharged into the atmosphere). The result was a significant reduction in erosion compared to the expenditure pattern of air cushions.

So makarom in Kiev in the years 1970-1980 were taken and passed the tests all the elements actually applicable chassis hovercraft. At the same time found a way which allows you to minimize the most significant shortcoming ball screws — strong dust generation and soil erosion. The acquired experimental data and the acquired experience can assign that recognizing the need for the creation of the landing gear on an air cushion for transport aircraft languishing at ASTC. Antonov DC has all the ability to be successfully undertake the work.

Aircraft performance characteristics of the Russian experimental aircraft on an air cushi
on AH-14SH:

Wingspan — 21.99 m;
Overall length — 11.36 m;
Overall height — 4.63 m;
Wing area — 39.72 m2;
Empty weight — 27200 kg;
The biggest take-off weight — 3420 kg;
Mass of fuel — 290 kg;
Motor Type — 2 PD Progress (Ivchenko) AI-14RF;
Power on each engine — 300 hp;
The highest speed — 209 km / h;
Cruising speed — 165 km / h;
Operational range — 450 km;
Service ceiling — 4500 m;
Crew — 2 people.

Based on materials from the website airwar.ru

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