OKB Mil could create the world's first rotary-wing transformer, but lost the palm to Bell
Periodically, at various exhibitions of weapons and military equipment, mock-ups, and even prototypes of convertiplanes preparing for the first flight, appear. Both foreign and Russian, created on an initiative basis. And this provokes discussions on the topic " Whether the Russian Army needs these specific aircraft and what they can be useful."
The question is not easy. Especially when you consider that for almost a century of theoretical and practical research and experiments in the world to date, there is only one commercially produced and operated tiltrotor-the American Bell V-22 Osprey.
The first attempt
A tiltrotor is an aircraft that combines the principle of operation of a helicopter during takeoff and landing and an aircraft with pulling screws during horizontal flight. Its main advantage is the ability to operate without runways and at the same time surpass classic helicopters in speed and range.
The idea of building convertiplanes was born and rapidly developed in the form of numerous projects in Russia, Europe and the United States during the transition of aviation from a child's state to a teenager – in the 20-30s. However, the case did not go further than the construction of inoperable samples for a long time. But even then, the theory of "helicopter-aircraft" was almost completely formed.
Among the many proposed ways to transfer the aircraft after takeoff into flight mode, two of the most realistic ones stood out – the vertical scheme of the tiltrotor and the horizontal one.
The vertical scheme is a conventional aircraft mounted on the tail. Located at the top of the aircraft, the propeller creates lift during takeoff. Having risen to a sufficient height, the device is transferred to a horizontal position and performs a flight in airplane mode. This scheme has the advantage - when lifting the aircraft wing does not interfere with the air flow.
"News agencies periodically hear anonymous statements from sources in the defense industry and the defense ministry that a tiltrotor is being created in Russia in the interests of the Airborne Forces ”
However, the disadvantages are much more significant. The pilot in two flight modes must occupy two different positions inside the cabin, turning the seat 90 degrees. The instrument panels should also be rotated at the same angle.
The closest to the creation of a serial machine of this type was approached in 1954 by Convair, which created the XYF-1 Pogo tiltrotor for the US Navy. It had excellent flight characteristics – the maximum speed exceeded 900 kilometers per hour. However, the sailors refused this machine, calling it a "damn stupa". The project was closed due to the fact that when landing XYF-1 Pogo made crazy and unpredictable jumps. An ordinary pilot was not able to pilot it.
With the horizontal scheme, the fuselage was always in the normal position. The axes of the screws were rotated 90 degrees, which, when turned, turned from lifting to pulling. According to this scheme, the vast majority of convertiplanes were designed. The first domestic project of the aircraft with a rotary wing "Sokol" was developed in 1936 at the Moscow Aviation Institute. Then there were projects and prototypes of convertiplanes of various degrees of readiness like the P. 1003 / 1 of 1938 of the German company Weserflug or the German model Focke-Achgelis Fa. 269 of 1942. There was also a 900-kilogram Transcendental Model 1-G (USA), which in 1951 made almost a hundred manned flights, but eventually crashed.
In 1955, a serious Bell company began to work, which, by order of the US Navy, created a two-ton XV-3 machine, which made test flights until 1966. Then the XV-15 was built with a maximum take-off weight of 6800 kilograms. Based on this development, the aforementioned Bell V-22 Osprey was created, which made its first flight in 1989.
There is also a contribution of the Soviet Mil Design Bureau in this series. The project "vintoplana" Mi-30 began to be implemented in 1972. By the early 80's, three versions of the machine were designed with two lifting / pulling screws on both sides of the wing. The heaviest version with a take-off weight of 30 tons was intended for the military. It was equipped with two D-136 engines used in the Mi-26 helicopter with a payload capacity of 20 tons. According to calculations, the Mi-30 was supposed to develop a horizontal flight speed of 500-600 kilometers per hour and have a range of 800 kilometers.
In 1981, the Mi-30 was included in the State Armament Program for 1986-1995. However, perestroika ran out of money, and the project was closed. But it can be assumed that if the work was brought to an end, the world's first production tilt-rotor osprey could appear in the Soviet Union.
A car worth 72 lives
But this could not happen, because 10 years of development, as the American experience shows – is quite a bit for such a complex machine as a tiltrotor.
The tender for the creation of a tiltrotor was won by Bell in 1983. In 1989, flight tests of six prototypes started. And in 2007, the operation of a new machine began, as it turned out, extremely complex and unstable, the tests of which claimed 30 lives. That is, it took 24 years to develop the V-22. However, it is necessary to add at least seven more years that were spent on the XV-15 tiltrotor, on the basis of which the V-22 was created. It turns out 31 years. And before that, there was an even earlier XV-3. That is, the history of creation goes back to the 50s.
The main difficulty faced by the developers was the extremely unstable state in which the tiltrotor turned out to be when the propellers were transferred from the lifting (helicopter) mode to the pulling (airplane) mode. During this transformation, the lifting force is sharply reduced and the car becomes unmanageable. But in the end, Bell engineers were able to deal with this problem.
To date, 400 convertiplanes of three modifications have been built: transport-amphibious, anti-submarine and rescue. The largest number of V-22s is used on the Marine Corps ' universal landing craft (ILC). They are also purchased for the Navy (anti-submarine) and the Air Force (for special operations units similar to our Airborne forces).
The mass of the empty V-22 is 15 thousand kilograms, the maximum take-off weight is 27 500 kilograms. The payload weight is 5500 kilograms. The diameter of the screw is 12 meters. Cargo cabin capacity – 24 paratroopers. Crew – three or four people, depending on the modification. Engine power – 2x6150 horsepower. The combat radius is 720 kilometers. Practical range without refueling – 2600 kilometers. Maximum speed – 565 kilometers per hour, cruising-510. The practical ceiling is 7600 meters.
V-22s for the KMP are equipped with two 7.62 and 12.7 mm machine guns. It is possible to install a hanging container with a 30 mm gun. However, it was soon abandoned due to the fact that the container significantly weighs down the structure. Five years ago, light air-to-surface missiles and gliding bombs were added to the Osprey armament.
The convertiplanes operated in the ILC have long taken part in transport and rescue operations in Iraq and Afghanistan. They were also on their way to Kuwait, where they participated in the rescue of the crew of a downed tanker plane. In 2017, in Yemen, during the evacuation of ground troops, a V-22 made an emergency landing, hit by militant fire. The crew was not injured, but the tiltrotor was destroyed by a missile strike by American aircraft.
Despite the fact that the designers of the Bell company solved the main problems of stability and reliability, for 12 years of operation, seventeen V-22s were involved in accidents, as a result of which 42 people were killed. At the same time, the tiltrotor is recognized as a convenient and reliable machine. In this connection, they are used instead of helicopters by major American politicians, including Trump, when visiting hot spots.
"Heavyweights" are waiting for funding
In Russia, with varying degrees of prospects, several companies are working on the creation of a domestic tiltrotor on an initiative basis. From projects brought to the stage of flying samples, literally ripples in the eyes. This is what we have in theory rather than in practice today. And all the developers of these projects offer their cars to the Ministry of Defense.
Founded in 2014, the company "Aerokso" by 22 employees has already created a proven unmanned tiltrotor "ERA-54". Take-off weight-23 kilograms, payload-three kilograms, speed-100 kilometers per hour, range-100 kilometers. The company is working on a new model, the characteristics of which should increase three to four times.
Also, the young company ZALA Aero, part of the Kalashnikov Concern, presented at the ARMY 2020 forum an unmanned convertiplane ZALA 421-16EV, capable of flying for two hours at a speed of 110 kilometers per hour.
Founded in 2015, the company ADA Aerospace with an authorized fund of 10 thousand rubles has created an unmanned tiltrotor Triada Mk. III, capable of delivering 15 kilograms of cargo to 300 kilometers at a speed of 200 kilometers per hour. It is designed for search and rescue operations.
Last fall, the Agency of the Far East for Attracting Investment and supporting Exports held a presentation of an unmanned tiltrotor with a load capacity of 300 kilograms. Its speed is 500 kilometers per hour, its range is three thousand kilometers. Production will be launched in 2022 after a sufficient amount of investment is collected. The developer is not named. And quite an incredible statement: "The regional authorities offer the initiator of the project a site in Komsomolsk-on-Amur, where the local aviation plant operates." That is, where the Su-35 and Su-57 fighters are being built. Ostap Bender was more circumspect in his speeches.
There are also more thorough projects that companies that belong to the "middle weight category"are engaged in. The company " Kronshtadt-technologies "in 2016 for the first time raised in the air a prototype of an unmanned vehicle"Fregat". Its length reaches 13 meters, wingspan-17 meters. Take-off weight-seven tons. Payload – one ton, when taking off by plane-1.7 tons. The flight range is 2300 kilometers, the ceiling is seven kilometers. The speed is 550 kilometers per hour. Work continues, but the degree of readiness of the "Frigate" is unknown.
The company "VR-technologies" creates a tiltrotor in three stages. In 2017, flight tests of a 300-kilogram unmanned experimental vehicle were conducted. On its basis, it was also supposed to create an unmanned tiltrotor with a take-off weight of two tons. It was intended to be mass-produced for the needs of the gas and oil industry. And then it was supposed to be the turn of the development of a heavy manned vehicle for the needs of the Ministry of Defense. And it should turn out, as stated in the holding company "Russian Helicopters", which includes "BP-technologies", no worse than the American tiltrotor V-22.
This statement was made three years ago. But, unfortunately, the further trace of even the intermediate version-two-ton was lost in the calendar. Nothing is known not only about the serial production of the intermediate machine, but also about its readiness for flight tests. All the company's efforts are aimed at creating VRT300 and VRT500 light helicopters. Any traces of the tiltrotor have disappeared from the company's website. And this is quite natural, because the sale of 50 percent of the company's shares to the Dubai Airshow company is being prepared. And she is only interested in the VRT300 and VRT500, which will be used as a taxi for the delivery of air passengers to any corner of the Emirates.
At the same time, news agencies periodically hear anonymous statements from sources in the defense industry and the defense ministry that a convertiplane is being created in Russia in the interests of the Airborne Forces. And this should be a very serious multi-ton car. And it should be created by very serious teams of designers who have accumulated extensive experience in the field of helicopter construction.
However, there is no information that any of the "heavyweights" are engaged in such work. And the main ones, as you know, are OKB Mil and OKB Kamov, which are now united in the National Center for Helicopter Construction named after M. L. Mil and N. I. Kamov. And in the archives of the Mil Design Bureau, if any, there should also be a detailed, but unrealized project of the Mi-30 tiltrotor. And it would be reasonable to assume that if this machine was really needed by the Ministry of Defense, then work on its creation would be resumed. Because this is the shortest way to achieve the result. The beginning of development from scratch could be completed closer to the middle of the century.
Convertiplanes could be used in the Navy as transport and amphibious vehicles. However, for their deployment, it is necessary to have universal landing ships, such as the Mistrals that sailed past us to Egypt. Their own are unlikely to appear in the foreseeable future, since they are more expensive than cruisers.
And in the Airborne Forces, they would be appropriate when performing special operations that involve throwing troops into the enemy's rear. And not necessarily these operations can be combat. These vehicles would be very useful in Syria for the evacuation of downed Russian pilots, as they significantly outperform helicopters both in speed and range. They would also be good in Nagorno-Karabakh when the forward detachments of the peacekeeping contingent are deployed.
Vladimir Tuchkov
The newspaper "Military-Industrial Courier", published in issue No. 50 (863) for December 29, 2020
