The main prerequisite for the emergence and development of this concept was the desire to abandon the runway, the construction of which during the period of hostilities not only increased the running costs, but also meant the loss of the potential advantage over time. We offer you a brief insight into the history of VTOL devices using photographs from the archives of the US federal government and a number of open sources.
In 1947, the US Navy and Air Force, based on the results of German research, began work on the project "Hummingbird".
In their research in the field of VTOL, the Americans actually mentally repelled from the design of an aircraft patented in 1939 by Professor Heinrich Focke, the creator of Focke-Wulf aircraft.
The development and construction of the XFV-1 VTOL aircraft was carried out by Lockheed since 1950, simultaneously with the development of the Conver VTF XFY-1, but with the same requirements fleet USA to a vertical deck fighter. Under the contract worth $ 10 million, construction of two experimental fighters was envisaged.
Focke-Wulf VTOL was conceived according to the now-known “screw in ring” principle. More precisely, in the center of the aircraft with an unnamed turbojet engine should have been two huge propellers that rotated in opposite directions. Although the professor, according to some information, worked even after the war, the matter didn’t go further than the wooden model for tunnel tests.
As for the United States, in the 1950 year, they receive two proposals for the “vertical” aircraft project - from Lockheed and Convair. The most interesting thing is that none of the developers followed in the footsteps of Heinrich Fock. It can be said that in the first American projects VTOL was perceived as something extremely literally.
Such a variant of vertical take-off was proposed by Professor Heinrich Fock
One way or another, both companies signed a contract with the military and provided prototypes in the middle of 1951. The Lockheed machine was initially called XFO-1 (Model 081-40-01). Samples, there were two, were worn 138657 and 138658. Later, Lockheed changed the designation to XFV-1 Salmon ("Salmon"). The Convair aircraft was simply called the XFY-1 Pogo.
We will talk in detail about Lockheed's brainchild, since there is more information about it, and the development of Convair is practically no different from it. In general, “Salmon” was named after the head of a group of engineers, test pilot Herman Salmon (Herman Salmon), who also had a nickname - “Fish” (“Fish”).
Both during takeoff and during landing, the Salmon (11,27 meters in length) was in an upright position, standing on a cruciform tail with a shock absorber and wheel on each of the tips.
Consisting of a pair of connected turbines T38, the Allison YT40-A-6 engine with horsepower 5850 “wound up” a pair of three-bladed propellers each with a diameter of 4,88. It was assumed that, lifting off the ground, "Salmon" will take the usual horizontal position in the air, and on returning it will turn over again and sit vertically on its tail.
November 5 1954 of the year. Convair XFY-1 Pogo makes a demo flight
According to calculations, the maximum salmon speed should have been 933 km / h, and cruise 659 km / h. Weight: kg 5260 empty, 7348 loaded. Wingspan 9,4 meter. In service should be four 20-millimeter cannon or forty-six 70-millimeter missiles placed in the wings.
To get into the cockpit, the pilot had to use a kind of scaffolding
VTVP XFV-1 is made according to the scheme of a monoplane with one TVD with coaxial propellers and four-bearing chassis.
The fuselage is a small extension, with a protruding cockpit lantern. The pilot's seat could deviate by 45 °, as on an XFY-1 aircraft.
The wing is straight, trapezoidal in plan, with a small relative thickness of the profile, characterized by the absence of mechanization. At the ends of the wing provided for the installation of additional fuel tanks or containers with weapons.
The plumage is X-shaped, arrow-shaped, with aerodynamic control surfaces and trimmers.
Four-support chassis, non-retractable, with four shock-absorbing struts in fairings at the ends of the X-shaped tail assembly and small wheels. For the initial stage of flight tests, an auxiliary landing gear with two racks and struts attached to the fuselage and relatively small wheels was installed, as well as additional racks with small wheels on the two lower surfaces of the tail unit.
In the future, the aircraft was placed on the Allison YT-40-A-14, as on the XFY-1 VTOL, which was supposed to be replaced by the more powerful YT-40-A-16, with a total equivalent power of 6825. with, and coaxial three-bladed screws Curtiss-Wright "Turboelectric".
Convair XFY-1 also flew. Above San Diego. And without a chassis
I must say, the pilot who drove the XFV-1 in proud solitude was less fortunate. Not only did his place roll over to 45 degrees, so also the entrance / exit from the cockpit required a special staircase.
In November 1953, the first tests passed, and on December 23, the 1953 plane operated by Herman “Pisces” made, finally, a brief flight. The first official flight took place 16 June 1954 of the year - the plane coped with soaring quite successfully.
For testing "Salmon" had to still attach chassis
However, the vertical takeoffs and landings on the tail of the XFV-1 actually never made - they started it all the same from a horizontal position, for which they made a temporary, as it then seemed, chassis.
Almost immediately it became clear that the existing turboprop engine cannot guarantee safety. There was not enough power, it was necessary for at least a couple of thousand "horses" more, and such an engine - YT40-A-14 - was expected. Unfortunately, the 7100 did not get the salmon horsepower - the engine just did not do for him.
In June, 1955, the XFV-1 project was closed in the same way as the Convair XFY-1 Pogo project (280 on a tethered flight in a hangar, one free flight in 1954 with transitions to the horizontal position).
The American program of turboprop, sitting on the tail, was completely folded. After the cancellation, prototypes were transferred to aerospace museums. The project was not successful for several reasons: first of all, due to the lack of engine power and reliability in general, as well as due to the experimental skills required for the pilot to land the plane on the tail.
I must say that the Americans refused just in time.
VTOL XFV-1 had the same powerplant as the VTOL XFY-1, but significantly different from him in the layout, having a straight wing and X-shaped tail. Like the VTOL XFY-1, the experimental XFV-1 aircraft had a vertical position of the fuselage, which rests on non-retractable landing gear, while stationary; however, the vertical take-off and landing were not perfect. For the initial stage of flight tests, the VTOL was equipped with auxiliary landing gear for take-off, take-off and landing with run.
The construction of the first experimental VTOL XFV-1 was completed on February 23 1953, and the first run-off flight with the help of auxiliary landing gear was made on July 16 by test pilot Herman Salmon, after whom the plane was named “Salion”.
Characteristics VTVP Lockheed XFV-1
wing span 8,43 m
16,66 aircraft length m
screw diameter 4,88 m
Engines 1 Allison YT-40-A-14
5260 engine power l. with.
take-off weight 7170 kg
empty aircraft 5327 kg
Flight data (estimated);
at the height of 4575 m 934 km / h
maximum rate of climb 60 m / s
practical ceiling 10 670 m
flight duration 1,22ch
In parallel with the Lockheed company in December 1946, the company "Ryan" proceeded to the preliminary design of a jet aircraft with a working designation "Model 38". The chief designer appointed the chief engineer of the company Ben Salmon (Ben Salmon), who began his work with the search for the most suitable engine. The main criterion for evaluating TRD was its specific gravity, i.e. the ratio of the mass of the engine to the maximum thrust. The smaller this number, the better. This figure for Rolls-Royse's English engine Nene was about 0,31 kg / kgf thrust, but it was not at the disposal of Ryan. Continuing the search and considering about eight more models of turbofan engines manufactured in the United States, Salmon settled on General Electric's J33 with a specific mass of 0,39 kg / kgf.
10 January 1947 The design team completed the first tests of the characteristics of the "38 Model". They showed that the equipped aircraft will weigh as much as 3405 kg, which means that one J33, developing 2090 kgf thrust, will not be able to vertically lift the device into the air. Then Salmon decided to use four powder accelerators JATO at the start. After takeoff, the pilot had to drop them and go to a horizontal flight. When, after completing the task, the plane returns to the place of launch, its mass will decrease due to the spent fuel, and it will be able to perform a vertical landing. This version of the machine received the designation "38-1". Fearing that the sailors would not like it, Salmon developed two more versions - "38-2" and "38-3" for a hypothetical turbofan engine with more than 3500 kgf.
In March 1947, all three projects were presented to the Navy. During the report, Salmon raised the main problems that had yet to be resolved during the work on the “38 Model”. The most difficult was the problem of controlling the apparatus on hover. If on a VTOL with turboprop engines in this mode, conventional aerodynamic rudders were used, which were blown with a powerful air flow from the screws and almost did not lose efficiency, then they became useless on a jet plane, and the control should be applied to change the direction of engine thrust. Ryan and Salmon were able to convince the military that all difficulties could be overcome. This allowed 24 to sign the April contract for 50000 USD, which included conducting research and building a flying airplane model.
Theoretical studies lasted more than a year. During this time, a group of developers has considered about 80 variants of various control systems. As a result, 24 June 1948 g, Salmon presented the project of a flying remote-controlled stand. It was a tubular frame with a J33 engine, to the extension pipe of which a deflectable nozzle was attached using a swivel. Part of the hot gases was discharged through heat-resistant pipelines to two small rotary steering nozzles, the differential deviation of which allowed the apparatus to rotate around the longitudinal axis. Stand built at a factory in San Diego. To ensure the safety of the staff, it was hung on a cable, and the test site was fenced with steel sheets. Management was carried out by cable. The first engine was turned on 20 in October 1950, and the first “flight” with a working control system took place on 31 in May 1951. Finally, the dream of Ryan engineers began to take on real forms. But since the signing of the contract, more than 4 years have passed, the allocated money has run out, and the 38 aircraft is obsolete. It was necessary to develop a new fighter and re-start negotiations with the military.
21 September Salmon proposed to the fleet a draft of a vertically taking off aircraft armed with four 20-mm cannons, which was several times heavier than its predecessor. It was planned to equip it with the J53-GE-X10 engine developed by General Electric with a 8000 kgf engine. The proposal did not cause much interest, because such a VTOL could not be built in the near future, and work on the project "38" was finally stopped. But "Ryan" did not give up. Almost two years later, she managed to convince the military of the need to resume funding for research.
The new machine with a delta wing and T-shaped tail unit received the designation "38R". It was designed for a real Pratt & Whitney J57-PW-11 engine with a thrust of 6600 kgf. In February 1953, the Navy was awarded a contract with Ryan to conduct preliminary research and build flying models. However, the Korean War intervened in the course of events. At the end of the summer, the command of the Navy sent Ryan a letter in which he informed about the break of the agreement: "... due to the reduction in the number of research programs." By that time, the Conver company had already begun flight tests of the Sea Dart jet naval flying boat and was completing the construction of a VTOL aircraft with an XFY-1 Pogo turboprop engine. The Lockheed company also did not lag behind - the flight of its "vertical" XFV-1 Salmon was planned for the fall of 1953. Against the background of these successes, Ryan's developments looked unpromising, because she needed several more years to design and test.
It turned out that the best designers of the company worked for seven years for nothing! Claude Ryan did not want to come to terms with this and continued to fight for the project, offering him to the fleet's eternal rivals - the Air Force. Representatives of the Air Force General Staff agreed to finance the program, which 1953 officially notified the company in August. In accordance with the contract Af33 (600) -25895, two experimental aircraft were to be built, called the X-69 Vertijet model. The key to success was the Avon English engine of Rolls-Royse, which was then considered one of the best in the world and was used on most British aircraft. The specific gravity of the selected version of the RA RA 13 was only 28 kg / kgf, and the maximum thrust reached 0,28 kgf.
They say that everything new is well forgotten old. Engineers "Ryan", starting a new project, returned to their old flying stand, which local wits called for a loud roar and anchored state "chain dog." An empty tank from a B-47 bomber was hoisted onto the apparatus, making an improvised cockpit for it. 24 November 1953 Test Pilot Peter Girard “raised” a tethered stand. Then he made a few more tethered flights, developing management skills.
At this time, the Ryan design team, led by new chief engineer Curtiss Bates, was working on the Vertiget’s drawings. The aircraft had an tailless aerodynamic configuration, the most advantageous in terms of weight, and a high wing. In the middle part of the fuselage was the engine, the air to which came through the side air intakes. To improve visibility in the vertical position of the fuselage, the pilot's seat was tilted forward by 45. In horizontal flight, the plane was controlled by elevons and rudder, in the vertical main control body became the deflectable engine nozzle, and the differential deflectable gas rudders mounted on the wing tips, the air for which was taken from the TRD compressor, were used to rotate the vehicle relative to the longitudinal axis. The pilot controlled the nozzle and gas rudders, using the usual control stick aircraft and pedals.
After blowing through the wind tunnel, it turned out that when flying at high angles of attack, especially during the transition from horizontal to vertical flight, the keel, despite its solid dimensions, will be shaded by the fuselage. Therefore, in order to maintain longitudinal stability, additional vertical surfaces were attached to the wing tips of the Vertidzhet. The estimated maximum take-off weight of the car was 3630 kg, which allowed us to obtain the thrust-to-weight ratio of 1,25 - more than enough for a vertical take-off.
A unique feature of the X-13 project was the complete absence of a wheeled chassis. The plane was supposed to land and take off from a vertically installed platform, developed in the technical department "Ryan" under the leadership of Robert Furman (Robert Fuhrman). For its production took the firm Freuhauf Trailer card Company. In the upper part of the platform between the two articulated beams, a steel cable with a diameter of 25,4 mm was tensioned, to which the "Vertiget" was suspended using a nose hook. During takeoff, the pilot slowly increased the engine thrust, the plane began to rise up, and the hook went out of engagement with the cable.
After that, the pilot took the car away from the platform to a safe distance, gained altitude and went into horizontal flight. During the landing, the pilot, setting the X-13 vertically, flew up to the platform and hooked onto the rope. After reducing the engine "Vertidzhet" sagged on the cable and rested on the platform with two bumpers of the pyramidal type. The beams turned down, pressed the cable to the platform, fixing the nose of the X-13. In the stowed position and when servicing the aircraft, the platform was horizontal. "Vertidzhet" moored to her with files. The platform was raised and lowered by two telescopic hydraulic jacks. The platform was mounted on a four-wheeled chassis and could be transported by truck.
The assembly of the first copy of the machine (factory 54-1619) began on January 20 1954 of the Glider and the main systems were assembled in June.
But the engine was delayed somewhere, and the car was able to be prepared for flights only by the end of 1955. Realizing that such a complex device must be tested consistently and carefully, avoiding unjustified risk, the designers decided to equip the Vertijet with the usual three-bearing chassis and fly around it in the traditional way. The plane was transported on a trailer to the Air Force Flight Test Center at Edward Air Base. On the morning of December 10, 1955, after several test runs, Peter Girard raised the X-13 into the air. The pilot quickly discovered that the plane had serious problems with controllability, it was intensively swaying in the air in roll and course. Despite the difficulties in piloting, Girard stayed in the air for about 7 minutes and made a successful landing.
After this flight, the X-13 was modified for two weeks by installing dampers in the respective control channels. The second flight took place on December 24. Now the car behaved much better, and Girard was pleased with her aerobatic qualities.
In the next test phase, the X-13 was to be tested during vertical take-off and landing. Bates and Ji-Rard did not have complete confidence in his predictable behavior in these modes; the plane could easily be thrown to the side or spun with a jet torque from a rotating compressor and an engine turbine. In such a situation, "Vertidzhetu" it is desirable to be as far as possible from the platform, and it is best to remove it altogether. Therefore, we decided to temporarily place the aircraft in a vertical position with the help of a tubular four-wheel frame attached to it. To compensate for the weight of the frame, the elevons, the rudder, the lantern, and part of the wing washers were removed from the Vertidzhat, which made it possible to keep the thrust-weight ratio at the same level. For landing the pilot in the cabin attached to the frame ladder.
28 May 1956 Mr. Girard made the first vertical takeoff. Reaching the height of 15 m, he began to decline with a small horizontal speed and successfully planted the X-13. The expected promotion of the aircraft Girard did not find. The only comment the pilot made to the power plant control system, which did not ensure the adequacy of the position of the throttle engine to the engine operation mode. This problem was solved rather quickly due to the refinement, which made it possible to coordinate the speed of movement of the ORE with the speed of change of the engine thrust. In the next flight, the pilot praised the innovation. In general, hovering in the air "Vertidzhet" behaved steadily and confidently controlled.
On the day of the first vertical take-off, the second experienced X-13 54-1620 was connected to the test program. Structurally, he almost completely repeated his predecessor, with the exception of the additional gas-steering wheel installed at the tip of the keel, which facilitated the stabilization of the machine in pitch. In the first flight of the "Veridzhet" 2 piloted by test pilot Louis Everett (Lou Everett).
In subsequent flights, they began to work out a method of approaching the platform and landing on it. According to the developers, the accuracy of the aircraft’s exit to the cable that the nose was clinging to was about 50 cm. During tests, Girard showed that the control system allows the pilot, using hints from the ground, to output X-13 to a given spatial position with accuracy before 10, see. After these flights, the test team found complete confidence in the success and began to prepare for the first take-off from the platform with a standard landing on the cable. From the first "Vertidzhet" removed the frame and again installed wheeled chassis. After several preliminary flights, Girard for the first time in the history of jet aircraft made the transition from horizontal to vertical flight. Hanging a few seconds in the air at an altitude of 1800 m, he returned the X-13 to a horizontal position and made a successful landing on the runway "like an airplane." This historic event took place on November 28 1956. Then followed training flights in which Girard and Everett trained to cling to an inch cable stretched between two searchlight towers. Both vehicles flew four-frame frames. Especially for this phase of testing, the specialists of "Rien" replaced the metal X-13 cones with wooden ones, which were easily replaced if they were damaged when they hit the cable. The exact exit of the aircraft to the cable was provided by teams from the ground.
Now, to work from the platform, it remained to learn how to fly up to it. The fact is that in the vertical position the aircraft approached the platform "belly", and the pilot did not see where he was flying. He needed some kind of benchmark to assess his position relative to the platform. The six-meter pole painted in a red-white strip, which was horizontally attached to one of the beams holding the cable, became such a guideline. In addition, a high stepladder was installed near the platform for the landing operator, who prompted the pilot to radio his location. The operator was instructed to control the beams, between which the cable was tensioned. They were in an intermediate position, at the right moment the operator abruptly raised them at an angle around 20 and "hooked" the hung X-13.
Equipment upgrades and pilots training were completed in spring 1957. 11 April, the first X-13 was installed on the platform. "Vertidzhet" had a wheeled chassis with a hook on the front desk, and if all attempts to cling to the cable ended unsuccessfully, the plane could be landed in the traditional way. Girard took his place in the cockpit, and the platform was set in the starting position. The pilot tilted his seat forward to 45 and started the engine. Having increased the thrust, he got out of engagement with the cable and began slowly, "backwards" to move away from the platform, holding the device at the height of 3-4 m.
Having flown a couple of tens of meters, Girard deployed the X-13 to 180, gained altitude and moved to horizontal flight. Landing took place in reverse order. Approaching the platform on the 5-6 m, the pilot found that the cover of the cockpit canopy completely obscured the striped pole. I had to rely on the operator’s commands. The lace attached to the nose bar turned out to be a very useful device, by the deviation of which it was possible to judge the direction of movement of the X-13. Hooking on the cable, Girard lowered the thrust and the car touched the platform. Historical flight is over. After it, the cockpit lantern was altered, having arranged a window on the left side to observe the pole.
“Ryan” deservedly celebrated success, because “Vertidzhet” was deprived of most of the shortcomings inherent in VTOL of the Lockheed and Conversion firms, in particular, the vibrations of propellers and the power plant, the effects of the proximity of the earth, etc. The landing process on the X-13 was simpler and safer. Moreover, the use of the cable gave the "Vertigetu" versatility. After all, it is not at all necessary to use a special platform, the cable can be pulled between large trees or bridge supports. Thus, the X-13 became a more likely type of tactical VTOL, than the XFV-1 and XFY-1. It remains to convince the military in this, competently showing them the plane.
The first public display of "Vertidzhet" was conceived by the wounded in the best American traditions. He was decided to be held at Andrews airbase near Washington, where more than 3000 military and journalists were invited. The specially prepared second copy of the X-13 could not fly over the whole country under its own power, and it had to be carried from the west coast by ship through the Panama Canal. On the morning of June 28, Girard and Everett made several demonstration flights on an unprecedented plane, prompting rave reviews from viewers. "Vertidzhet" easily sat on the platform, like a fly on the wall, clinging to it with his hook. Until now, no aircraft in the world can do this. Especially for these flights the platform was finalized. Placing a stepladder with an operator next to it was undignified, and in the upper right corner of the platform they fixed a square cradle painted black. The climax of the show was the X-13 flight from Andrews base to the Pentagon and landing near this famous building. "Vertijet" flew up to the Pentagon in a vertical position from the Potomac River in a cloud of water spray, making an indelible impression. However, Girard, who was in the cockpit, was not thinking about the external effect, but about the inexorably running out of fuel. Water splashes settled on the lantern, reducing to "zero" the already meager visibility. Only thanks to the operator, he landed successfully. X-13 once again made history as the only jet aircraft that made a full-time landing near the Pentagon. 12 September 1957 X-13 2 returned to Edward base to join the first copy, which military test pilots were already flying.
However, despite the successful showing and successful trials, the military stopped funding and closed the X-13 program. Together with the "Vertiget" covered and other development programs for VTOL aircraft with a vertical position of the fuselage. The main reason was the same for all - the complexity of take-off and landing for a pilot of average qualification. X-13 sinned by the fact that the gas jet from the TRD destroyed the concrete runway surface, and in field conditions would raise giant columns of dust, unmasking launch pads.
30 September 1957 X-13 took off for the last time. For some time, the Americans drove "Vertidzhet" to the aviation exhibition, where they showed it in a static exhibition. However, viewers quickly lost interest in X-13, and they gradually forgot about it. In May, 1959 X-VUMX Xtnumx was deposited at the US Air Force Museum in Dayton, and in I2, the Ryan company donated X-960 13 along with the platform to the US National Aerospace Museum.
Investigations of jet VTOL in France began in 1954, when the new company BTZ (technical bureau G. Zborowski), together with the well-known engine-building firm SNECMA, developed and proposed a project of a VTOL with a ring wing, known as "Coleoptere" (ring-winged). Like the American X-13 VTVP SNECMA C.450 Coleoptere, it also had to have a vertical position of the fuselage during take-off and landing, which seemed natural for a light combat aircraft, and the annular wing provides an adequate base for placing chassis supports on it.
Studies of coleopters were one of the main themes of the second congress of the German aviation society in 1954. It was argued that the use of an annular wing allows the integration of the powerplant with a wing, which can be used as an outer contour of a ramjet engine for supersonic airplanes, and for subsonic airplanes screws.
At that time, the designers working on the technology of creating an aircraft with an annular wing had the confidence that such an arrangement of the wing would allow a high-quality integration of the power plant into the wing of the aircraft for use as the outer contour of a jet engine. When using such a wing for airplanes with a subsonic speed, the resulting design will serve as the main channel for coaxial propellers. Almost all of the development of the time on the VTOL of the ring-type wing was based on projects captured in Germany, where work on these projects finally achieved some success.
It was emphasized that the proposed projects of coleopters are a development of research and design work carried out during the Second World War in Germany, where a number of original projects of VTOL aircraft were developed, including those with a ring wing. To study the operation of TRD control systems in a vertical position, an unmanned flying stand with a SNECMA "Atar" TRD was built and tested on a tether, which was designated the name SNECMA C.400-P1 "Atar Volant" (flying Atar), and then on a leash and in free flight, manned stand SNECMA C.400-P1. Stand tests were carried out for three years from 1955 to 1958.
The SNECMA C.450 Coleoptere ring-wing SVVP was developed by the SNECMA company under a research program, first with its own company funds, and then in accordance with the contract concluded with the German Ministry of Defense. The VTEC SNECMA C.450 Coleoptere had a power plant and systems that were tested on the C.XNNXX-P400 “Atar Volant” stand. The construction of the experimental C.2 Coleoptere was completed at the end of 450, and he began to undergo ground tests at the company's aerodrome in Milln Vilarosh, and then fly first on the hover mode (the first free flight was made on May 1958), and later the transition to horizontal flight. Test pilot Augustus Morel. During one of these flights 1958 July 25, the plane lost control at an altitude of 1958 m, crashed and burned, the pilot managed to eject at an altitude of 75 - 18 m, but as a result of an unsuccessful landing spinal injury.
During the investigation of the accident, it was found that the aerodynamics of the annular wing and the jet control system, which are features of the C.450 Coleoptere VTOL aircraft, were not its cause, but nevertheless SNECMA did not dare to continue the development program of this clearly ambitious project, although by that time the company has developed a number of original projects of combat jet VTOL with a ring wing (attack aircraft and a supersonic fighter-interceptor), as well as a project of a passenger VTAL with a turboprop and coaxial propellers.
The draft subsonic attack aircraft "Brush" provided for the recumbent location of the pilot in the cockpit. Takeoff and landing of both aircraft should be made in the vertical position of the fuselage using a turbojet engine, equipped with gas rudders. In the project of a supersonic interceptor fighter, the annular wing is the outer contour of a ramjet engine, which creates thrust at high supersonic flight speeds (M = 2,5), when the turbojet engine becomes uneconomical and disconnected. A number of projects of other combat aircraft with subsonic speed were also developed. as a power plant coaxial propellers in the annular wing, effectively working not only during vertical takeoff and landing, but also in horizontal flight. Coaxial propellers were also proposed to be used in the project of the multipurpose VTAG “Ganneton” with two theater engines. For the convenience of placing the pilot and passengers of the chair was supposed to perform turning.
The design feature of SNECMA C.450 Coleoptere is the vertical position and placement of the fuselage during take-off and landing in the annular wing, the aircraft is equipped with one turbojet engine and four supporting chassis, the airframe design is made by Nord. The all-metal fuselage is of small elongation, has a circular cross section in the zone of interface with the wing. A single-seat cockpit with a protruding lantern and side glazing for better visibility is located in the nose. The ejection seat CkaSE.120B is installed in the cab, which can deviate by 45 ° when the position of the fuselage is changed. The chair provides ejection in hover mode on the ground.
The wing is circular, made of light alloys, has a frame structure that supports the outer and inner plating, the outer diameter of the wing is 3,2 m, the inner one is 2,84 m, the chord of the wing is 3 m, the relative thickness of the wing profile is 12%. The wing has no mechanization. The plumage consists of four triangular surfaces located in the tail part of the wing, equipped with aerodynamic rudders and providing control in horizontal flight. Inside the annular wing, the outer control surfaces mate with four profiled swept surfaces connected to the fuselage. The four-bearing chassis is not retractable, installed on the wing in the root parts of the surfaces of the tail. Racks with oil-air shock absorbers have a large stroke and are equipped with self-orienting wheels with solid rubber tires.
The power plant consists of a single SNECMA "Atar" 101E turbojet engine with a static 3700 kgf thrust installed in the fuselage. Side air intakes, unregulated, the nozzle is equipped with gas rudders. The compressed air taken from the TRD compressor is channeled through the channels in the profiled surfaces inside the wing to the nozzles of the jet control system. The control system consists of aerodynamic control surfaces for control in horizontal flight and gas and jet control surfaces for control during vertical flight conditions. SNECMA C.450 Coleoptere operation was to be provided with a special trolley with a tilting ramp. For transportation, the SNECMA C.450 Coleoptere was mounted on a trolley in a horizontal position on supports, for take-off the ramp was installed in an upright position.
The branded feature of the C-450 Coleoptere is the vertical positioning of the aircraft during take-off and landing and the use of a ring-type wing. The experimental aircraft had a 4 supporting chassis, the power plant - one turbojet engine. The construction of the airframe was made to order by the company "Nord". The all-metal fuselage is made with a slight elongation and a circular cross section at the place of its coupling with the wing. In the front of the cabin is made for one pilot, having a protruding lamp and side glazing, giving an improved view. Inside the cabin is a seat with a catapult "Sud SE.120B", which has an angle of inclination to 45 degrees during the ejection.
Also the chair can be used on vertical modes of vletta-landing. The ring-type wing of the frame structure is made of light metal alloys with reinforcement of external and internal plating. The design of the wing did not use any mechanical parts. The main tail is made in the tail section on the outer and inner surface of the wing. Outer tail - 4-e triangular surface located cross. They are controlled by aerodynamic rudders that provide the aircraft with a horizontal flight. The inner tail is of the conjugate type with the outer tail, which has vitreous shaped surfaces connected to the body of the aircraft.
The aircraft has a non-retractable type 4-x landing gear. Racks made with the use of oil-air shock absorbers, got a good move and end with wheels of free rotation. Wheels have solid rubber tires.
Power - one turbojet mounted in the fuselage. Air flow control is carried out with the help of side air intakes of unregulated type and a nozzle with gas rudders. Compressed air emerging from the engine compressor passes through the channels of professional surfaces and reaches the nozzles of the jet control system. The system has aerodynamic rudders that control horizontal flight and gas-jet rudders that control the vertical flight of the aircraft. This system was successfully tested at the first stand and installed on the experimental aircraft “C-450 Coleoptere”.
For the transportation of the aircraft used special carts with a leaning ramp. When the aircraft was moved, it was installed in a horizontal position, and in order to take off, the ramp was fixed in an upright position.
- outer / inner wing diameter - 3.2 / 2.8 meters;
- wing chord - 3 meter;
- relative thickness of professional wing - 12 percent;
- engine - TRD 10IE "Atar";
- static thrust - 3.7 thousands of kgf.
- length 8 meters;
- speed 800 km / h;
- High-altitude ceiling - kilometer 3;
- weight of fuel 700 kilogram;
25.06.1959 of the year when performing the next test flight test pilot A.Morel could not cope with the control of the C-450 Coleoptere, as a result of which the aircraft from a height of 75 meters entered the corkscrew and crashed, and the pilot barely managed to make bailouts at a height of approximately 20 meters, but upon landing, received serious damage (spinal injury). The investigation showed that the characteristics of this VTOL, namely the design of the wing of the ring type and the airflow control system, had nothing to do with the crash that occurred.
However, SNECMA did not develop further use in the construction of ring-type wing airplanes, although it was already ready to create designs of combat vehicles — an assault fighter and a fighter jet interceptor. In addition, there were developments in civilian vertical take-off and landing vessels using TVD and coaxial screws.
This disaster was the last point in the implementation of the program Coleoptere. Despite the prospect of further development and the support of the French Ministry of Defense, the company SNECMA, having suffered huge losses, did not dare to continue further development.