More than a trivial cause "splitting the fuselage" — the convenience of placing the power plant. In the first years of the aviation designers experimented with a variety of aircraft assemblies and as a result of discovering, several studies outright two-beam scheme.
For example, one of the prerequisites to the creation of double-girder aircraft was the lack of synchronizers to fire through the propeller. As an example of such structures can take a fighter-reconnaissance Airco DH-1 British manufacturing. In the development of this aircraft designer J. de Haviland arranged workplace arrow in the bow. Because of this he could quietly firing a machine gun full forward hemisphere, without fear of destroying your aircraft. The engine and propeller at all it had to move to the back of the fuselage. But the application of this traditional scheme would entail the need to install pusher propeller with a suitable drive shaft or violation of balancing. Because de Haviland shortened fuselage applicable to the length of the arrow and placed the cockpit and the pilot, also Propeller engines of a string. Empennage he set at 2-remote farms that were attached at the edges of the push screw.
Aircraft DH-1 can be called only from a small twin-boom stretch. He did not have the "form" of fuselage beams, instead of which was equipped with with 2 lightweight trusses. At the same time, and in such a fighter-reconnaissance design de Havilland has demonstrated advantages of such a layout structure of the aircraft. In the coming necessity of a power plant and the release of the nose fuselage than once manifested itself in the form of an appropriate design of aircraft. Dvuhbalochnye scheme with the engine placed in the rear of the fuselage shortened more than once, and used in jet aircraft. As an example of such projects British fighter De Havilland DH.100 Vampire, Polish agricultural aircraft WSK-Mielec M-15 Belphegor or Russian spy M-17 "Stratosphere."
A place for guns
The second reason is connected with the placement of engines for which the designers have resorted to two-beam scheme, layout also has roots, but of another kind. Wanting to fully rescue the fuselage from the engines and auxiliary units, in the years of the First World War, the designers smart enough to make the two beams at the edges of the fuselage and put them all in the Propeller group. One of the first aircraft of similar heavy bomber was the Italian Caproni Ca.36. The engines of the aircraft were located on the wing, and immediately behind them were two longish beam serves as a fastener for the tail feathers. Inside the beams near the center of mass of the aircraft also installed fuel tanks. The vacant space in the nose and the tail of the main fuselage used to set the shooting points. Noteworthy that the tail gunner during the flight reshechatoy was sitting inside the basket.
In the coming this idea was used more than once, whereas the main specifically to make roo
m for feeding rifle point. A more famous example of such aircraft is a German spy Fokke Wulf FW-189 Uhu, also recognized by the nickname "Ram". Pilots of the anti-Hitler coalition often noted the complexity of the interception of the aircraft due to a very successful location of the tail guns, shooting almost the entire rear hemisphere.
Dvuhbalochnye scheme with the recommendations of the fuselage and engines used in the development of fighter aircraft. More well-known twin-boom aircraft of this class is the South American Lockheed P-38 Lightning. In the comparable small streamlined fuselage of the fighter left only the cockpit and barreled weapons. The side supports of the fuselage, in turn, is housed engines, tanks, turbochargers and radiators. With the right placement of units inside the beam could ensure a good balance, and a huge shoulder comparable tail gave the aircraft a good weight for its maneuverability.
Exciting way disposed releasably in place of the designers of the fuselage Northrop, creating a night fighter P-61 Black Widow. At the back of the shortened fuselage part of the equipment they have arranged radar detection of enemy aircraft, also provided a radar operator position.
Ability to increment the internal volume of the fuselage through the placement of all the ancillary engines in side supports just could not intrigue designers transport aircraft. Among other, double girder scheme allowed to increment the size of the tail flap for loading and unloading. In 1944, its own first flight made a freighter Fairchild C-82 Packet. Inside the comparable high and wide fuselage could fit almost 80 fighter with equipment or 42 paratroopers. At the rear of the fuselage designers have provided a huge flap cargo hatch, which can be reset as needed. Through the use of double-girder mounting tail plane C-82 was quite comfortable for loading operations: as required under the stabilizer could drive a truck, driving up the cargo specifically to the hatch.
The forthcoming development of C-82 was the aircraft C-119 Flying Boxcar. The new air truck with the huge size and weight could carry up to 4 and a half tons of cargo. Despite the increase in size and take-off weight, "flying car" niskolechko not lost in the convenience of loading and unloading. Over time the C-119 was a major tactical military transport aircraft in the U.S. military, had also been distributed to other countries.
In our country, too, were made to build the sample air-boom truck. In 90 years at the company "Sukhoi" was developed by a multi-purpose transport aircraft Su-80. Its assembly to a large extent similar to the previous double-girder transporters. At the same time, Su-80 has several unique features. So, for greater rigidity aft fuselage is further connected with the tail wheel with an additional plane, and tail stabilizer is on the tail fin, which allows for loading customized vehicles to the aircraft.
Specific "interpretation of the" two-beam scheme can be considered as some projects since the second World War. Then the warring states were needed fighters from long range. These aircraft have allowed to perform escort bombers during long flights over enemy territory. With a difference of a few months on both sides of the front there were two more than exciting project.
German designers under the direction of V. Messerschmitt in the middle of the war produced its own "double" fighter based on the Bf-109 aircraft. Modification of the index Bf-109Z assumed the assembly of the aircraft from 2-ordinary "One Hundred Ninth," a specially designed center-united and tailplane. With all of this control rudders and engines combined, and the controls to be displayed in the cockpit of the left "polusamoleta." Instead of the planned cabin right to install an extra fuel tank and replace the lamp with metal fairing. The Germans planned to make some choices Bf-109Z, designed to intercept air targets and attack ground. In 1943, construction began on the prototype of the dual plane, but it was never finished due to the presence of higher priority projects. The situation changed at the front is not in favor of Germany and the designers had to do more necessary and urgent puzzles.
In contrast to the German designers, South American were more fortunate. They managed to not only make the dual-twin-boom aircraft, and bring it to production. In addition, fighter North American F-82 Twin Mustang managed to record on his own account another "achievement": he was the last South American piston fighter. F-82 was a two P-51 Mustang, which connects the special fuselage center section. Instead of native stabilizers with elevators in the Twin Mustang establishes a single plane. All aircraft control system were duplicated, management could produce at least some of the cabin. It was assumed that the two pilots will be able to change each other during long flights. The first prototype of the P-82 flew only at the beginning of July 1945 and the aircraft did not have time to take part in the 2nd World War, which was created for. Later these fighters used during the Korean War. With all of this in most cases, the "Double Mustangs' doing puzzles in attack ground targets, as were no longer able to fight well with modern enemy fighters.
Another unusual version of the
two-beam scheme used the famous designer B. Rutan for the creation of a record of its own aircraft Rutan Voyager. The aircraft with a flight range of unique performance is a huge plane with a wing extension, comparable to a small fuselage and tail with 2 supports, which are mounted on the keels. The front of the beams brought forward fuselage and connected to an additional stabilizer. The main prerequisite for the introduction of so extraordinary system was to provide the necessary rigidity. Due to the elongated fuselage, wing and beam power elements were mass bending and rotating loads. The imposition of the keels on the tail boom and the transfer of the stabilizer to the front of the aircraft has permitted to provide sufficient hardness and strength of the entire structure. Unlikely plane Voyager without such technical know-how would be able to without landing proparhat more than 42 million km (40 million according to the FAI).
Production designed by Voyager have been applied in the development of more of the 1st record aircraft — Virgin Atlantic GlobalFlyer. Designed to order S. Fossett aircraft was similar to the Voyager assembly, but differ by some details. First, it is worth noting another powerhouse — turbojet engine on the fuselage. In addition, the stabilizer with elevators has been moved to the tail section. Two separate plane to "GlobalFlayere" were attached to the tail wheel, under the keels. In 2006, the pilot of the plane Fossett overcame the least bit GlobalFlyer 41.5 thousand kilometers. The average flight speed for all that was equal to 590 kilometers per hour. Through the use of new materials able to set the power not only to make better aircraft flight data record, and to ensure adequate strength of the structure. Specifically, the latter fact has permitted to abandon the front horizontal tail in favor of a more conventional stabilization systems and management.
Naturally, at this point have been described far not all aircraft made by two-beam scheme. The total number of aircraft to that of the assembly exceeds a few 10-s, and even the general description of the history of creation and design of writing a multi-volume reclaims the fundamental work. The fact that the girder circuit was tested in almost all classes of aircraft. On such a system were built fighters and bombers, transport and passenger planes, and even unmanned aerial vehicles. Whenever the use of two-beam scheme has been proved one way or another prerequisite. But despite all the success, these systems are not widely known and not replaced traditional scheme. The main reason — the need for the creation of small and strong tail beams. In addition, comparable small size of these units do not allow the aircraft to use their volume. For example, on U.S. transport workers inside the beams were only rudder control rod.
So the creation of two-beam scheme aircraft specifically requested certain grounds. This assembly has a number corresponding to "birth" of the pros and cons, the combination of which may not always be beneficial for the design of certain aircraft or on its practical perspectives. Because in over long years of double-girder assembly of aircraft to spread because of the lower yields of traditional versatility. Yet, in the future certainly will be new types of aircraft with a shortened fuselage and tail attached to the 2-pillars. The main thing that in the case of each particular project application such scheme was justified and reasonable.
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