The claimed utility model relates to the aviation industry, particularly to the systems for mechanical connection of modules and structural parts of the unmanned aerial vehicles (in particular, coupling a tail assembly with a center wing section / fuselage of a UAV).

To ensure mobility and reduce dimensions of a UAV and unmanned aerial systems in general raises a need of modular UAV design with a quick release system for connecting modules, which would provide an ability to quickly disassemble / assemble of airframe structural elements without additional tools for further transportation / storage in a transport packaging. Additionally, such a system should have sufficient toughness and reliability of the assembly, like an integral embodiment.

A classic screw connection is also widely applicable for mechanical connection of a tail assembly with a center wing section / fuselage of a UAV. So known from the prior art the «MUGIN 2600MM» UAV, which embodied according to twin-boom aircraft configuration, has the composite material tail booms which are fixed on a lower plane of a center wing section with inserts and four screws, then a tail assembly has related grooves for assembly with opposite ends of the tail booms and fixed with the screws (https://www.muginuav.com/wp-content/uploads/2019/08/Mugin-2 600- BuildGuide.pdf).

One of the main disadvantages of this embodiment of mechanical connection is a complexity of disassembly / assembly of a UAV, demand of tool using (at least screwdrivers), as well as the presence of small removable elements (screws, inserts) which may be lost during transportation or another operation. Analogs of the claimed utility model are also include an invention - «electrical connection structure, tail rod quick release structure and UAV having the same», which consists of the first wiring connection devices, the second wiring connection devices, a first connection element with thread that installed on the UAV fuselage, a second connection element with thread, which mounted on the tail boom of a UAV, first and second external tubes with thread, which embodiments a threaded joint between a first and a second structural elements of a tail boom and a fuselage, then fixing realize through spring-actuated casing tube with a thread (US patent N° US 2018/0257778 Al).

The disadvantages of this invention are large quantity of the structural members, structure complexity, the necessity of structure elements connections manufacturing with metal or alloys, which make weight increase of a coupling system, higher manufacturing accuracy requirements of individual system elements that makes production more complicated, comparatively increased complexity and preparation time for start of a UAV with such coupling system.

The prototype of the claimed utility model is a quick release fastening system, that used in "Penguin B" UAV design with a twin-boom tail assembly which joints to a center wing section with the docking chucks, which are consist of a pin attached to a center wing section and a horizontal stabilizer of a UAV and a crimp sleeve with holding screw which mounted at both ends of the tail booms and fixed on a pin due to the frictional force by tightening holding screws. Electrical wire bundles are placed inside of the tail booms and equipped with the «male-female» type connectors which mounts inside of the docking chucks (https://www.uvsr.org/docs/UAVFactory_Latvia_Penguin- B.pdf). This embodiment of the quick release fastening system partially simplifies assembly / disassembly of a UAV, however using of additional tools as in case the first analogue is required, and vibrations of a UAV airframe which generates by the propulsion system, bear the risk of fixing screws unbolting during operation, which resulting in uncoupling of the structural elements of a UAV.

The technical problem solved by utility model consist in creating the structural elements quick release fastening system of a UAV, which provides reliable connection of a center wing section / fuselage with a UAV tail assembly, does not require the additional tools for assembly / disassembly, provides fixing rigidity similar to integral coupling.

The technical result achieved by claimed utility model using consists in UAV structural elements quick release fastening system creating, which provides reliable connection of a center wing section / fuselage with the twin- boom tail assembly, no additional tools required and provides quick assembly / disassembly in the field conditions, has sufficient fixation rigidity comparable to integral coupling.

The technical task is being solved and technical result is achieved by:

- Using the docking chucks as a quick release coupling; - realizing of docking and fixation of the tail booms with a tail assembly by using the docking chucks of a tail assembly and a bayonet mount;

- realizing of docking and fixation of the tail booms with a center wing section / fuselage by using the docking chucks of a center wing section and the center wing section fixing pins, or by using docking chucks of a center wing section and a bayonet mount;

- possibility of using the quick release fastening system on a UAV with dismountable or integral tail assembly design. The essence of the utility model is shown on:

- fig. 1 - a horizontal stabilizer half (without top casing) with a tail assembly docking chuck illustration;

- fig. 2 - a tail boom (from tail assembly ^' s side) with L - type cutout illustration;

- fig. 3 - coupling method of the horizontal stabilizer halves;

- fig. 4 - a UAV center wing section with installed center wing section docking chuck illustration;

- fig. 5 - a tail boom with a UAV wiring bundle connector and the pin passing hole illustration (from UAV center wing section's side);

- fig. 6 - the tail booms with the center wing section docking chucks connecting method;

- fig. 7 - the tail booms with the tail assembly docking chucks connecting method; - fig. 8 - a center wing section fixing pin mount example (according to embodiment as a dismountable UAV's outer wings component);

- fig. 9 - an example of a UAV with the structural elements quick release fastening system in assembled condition.

The UAV structural elements quick release fastening system consist of at least two tail assembly docking chucks (1) mounted on the UAV horizontal stabilizer tips. The tail assembly docking chucks (1) are fitted out with the tail assembly locking pins (2) (at least one for each tail assembly docking chucks), that mounted perpendicular to the axis of at least two tail booms (3), each has at least one L-shaped cutout (4) on the tail assembly side for tail assembly fixing pin (2) passing and the bayonet mount realizing between a UAV tail assembly and the tail booms (3) (from side of a tail assembly). In another utility model embodiment, the tail booms (3) have at least one L - type cutout (4) both from center wing section's and tail assembly ^' s sides for center wing section fixing pins (6) and the tail assembly fixing pins (2) passing and the double-sided bayonet mount realization (both from center wing section ^' s and UAV tail assembly's sides). At least two center wing section docking chucks (5) are installed inside the body of a center wing section / fuselage fixedly and designed to connect the tail booms (3) with a center wing section or a UAV fuselage, have a hole for the center wing section fixing pins (6) passing, which (in one of the utility model embodiments) are dismountable part of the UAV outer wings or are separate structural elements or mounted in the body of the center wing section docking chucks (5) fixedly, similarly with the tail assembly (assuming that a bayonet mount is used both from tail assembly's and center wing section's sides). For fixing the fastening, the tail booms (3) have the tail booms holes (7) from the docking side with a center wing section / fuselage of a UAV (at least one hole to each of the center wing section docking chucks), which are concentrically to the center wing section docking chucks holes (8) (at least one hole for each of the center wing section docking chucks), for the center wing section fixing pins (6) passing.

In another utility model embodiment, the L - type cutouts (4) there are instead of the tail booms holes (7) from center wing section's side for realization a bayonet mount with a center wing section fixing pin (6). A double side bayonet mount in this embodiment is realize. Center wing section fixing pins / tail assembly fixing pins quantity relates to tail booms holes / tail booms L- type cutouts quantity from the corresponding side. The claimed utility model can be applied with dismountable or integral tail assembly. In case when utility model has applied in a UAV with dismountable tail assembly the horizontal stabilizer halves quick-release joint is needful and the docking plates (9) are also may been include in the system for this purpose and mounted on one of the horizontal stabilizer halves, coupling with the docking chucks (10) of a dismountable horizontal stabilizer and fixing by the quick release fasteners (11), which have flat surface and mounted flush with a UAV horizontal stabilizer cover to prevent impact on aerodynamics. External dimensions of the docking plates (9) correspond to the internal dimensions of the docking chucks (10) of a dismountable horizontal stabilizer. A dismountable horizontal stabilizer embodiment using provides a significant reduction in dimensions of a tail assembly in disassembled condition, quick assembly / disassembly and sufficient structure rigidity of a UAV tail assembly.

The electrical wire bundles are laid through the tail booms (3) and equipped with the «male-female» type connectors at the joint of the docking chucks (1,5) for wire installation through the tail booms (3). The UAV wiring bundles connectors (12) are mounted fixedly at the ends of the tail booms (3), mounted movably in the center wing section docking chucks (5) and mounted fixedly in the tail assembly docking chucks (1). Wire bundles have an extra length to simplifying UAV's assembly/disassembly and preventing the breaking of the UAV wiring bundles connectors (12) in case were tail booms are accidental hanging down on own weight.

According to the first embodiment of the quick release fastening system, the L - type cutouts (4) of the tail booms (3) are mutually opposite to each other from tail assembly ^' s side for implementation the opposite rotation bayonet mount of the tail booms with a tail assembly. Use integral or dismountable horizontal stabilizer consist of two halves, installed and fixed on the tail booms (3) by opposite rotation to each other (fig. 7) in this embodiment. Tail booms (3) are coupling with the center wing section docking chucks (5) from UAV center wing section's or fuselage ^' s side and fixed through by using the center wing section fixing pins (6) pass through the concentric center wing section docking chucks holes (8) and the tail booms holes (7). When the utility model is used on a UAV with dismountable horizontal stabilizer the system elements assembling sequence is as follows: 1) connection of the UAV wiring bundles connectors (12) from center wing section's side;

2) coupling the tail booms (3) with the center wing section docking chucks (5) (fig. 6) and moving them in docking chucks (5) up to the stop;

3) coupling the outer wings with the dismountable fixing pins (6) or their mounting in concentric center wing section docking chucks holes (8) and tail booms holes (7) (in their embodiment as the separate structural elements);

4) connection of the UAV wiring bundles connectors (12) from tail assembly's side; 5) coupling the tail booms (3) with the tail boom docking chucks (1) so the tail assembly locking pins (2) are coincident with L - type cutouts (4) of the tail booms (3) and moving them in docking chucks (1) up to the stop; 6) horizontal stabilizer halves rotation in their coupling direction (fig.7) for tail assembly bayonet mount lock; 7) horizontal stabilizer halves coupling and locking (fig.7).

When a UAV design with dismountable horizontal stabilizer is used the system elements assembling sequence is as follows:

1) connection of the UAV wiring bundles connectors (12) from center wing section ^' s side; 2) coupling of the tail booms (3) with the center wing section docking chucks (5) (fig. 6) and moving in docking chucks (5) up to the stop; 3) connection the UAV wiring bundles connectors (12) from tail assembly's side;

4) coupling the tail booms (3) with the tail assembly docking chucks (1), so the tail assembly locking pins (2) is coincident with L - type cutouts (4) of the tail booms (3) and moving them in docking chucks (1) up to the stop;

5) rotation of the tail booms (3) to each other in mutually opposite direction (depending on direction of L - type cutouts (4)) till stop for tail assembly bayonet mount lock;

6) coupling the outer wings with the dismountable fixing pins (6) or their mounting in the concentric center wing section docking chucks holes (8) and the tail booms holes (7) (in their embodiment as the separate structural elements).

According to the second system embodiment, L - type cutouts (4) of the tail booms (3) are fulfilled mutual unidirectional from tail assembly's side for the tail booms (3) with a UAV tail assembly bayonet mount realization. It is possible to use in this case integral or dismountable horizontal stabilizer that consist of two halves installed and fixed on the tail booms (3) by use unidirectional rotation. The tail booms (3) are coupling by center wing section docking chucks (5) from the side of a UAV center wing section / fuselage and fixed with the center wing section fixing pins (6) passed through the concentric holes of the center wing section docking chucks (5) and holes of the tail booms (3) from center wing section ^' s side. When the utility model is used on a UAV with integral horizontal stabilizer the system elements assembling sequence is as follows: 1) connection of the UAV wiring bundles connectors (12) from center wing section ^' s side;

2) coupling the tail booms (3) with the center wing section docking chucks (5) (fig. 6) and moving them in docking chucks (5) up to the stop;

S 3) connection the UAV wiring bundles connectors (12) of the UAV wiring bundles from the tail assembly's side;

4) coupling the tail booms (3) with the tail boom docking chucks (1), so the tail assembly locking pins (2) are coincident with L-type cutouts (4) of the tail booms (3) and moving them in docking chucks (1) up to the stop;

5) rotation of the tail booms (3) in docking chucks (1,5) in one direction (depending of L - type cutouts (4) direction) till stop, for tail assembly bayonet mount lock;

6) coupling the outer wings with the dismountable fixing pins (6) or their mounting in the concentric center wing section docking chucks holes (8) and the tail booms holes (7) (in their embodiment as the separate structural elements).

System elements assembly sequence with dismountable horizontal stabilizer is same as a first system embodiment. The difference is only in initial horizontal stabilizer halves asymmetrical position before bayonet mount lock and rotation (paragraph 5 of claimed utility model first embodiment assembly sequence implementation).

According to the system third embodiment, the tail booms (3) L - type cutouts (4) are made mutually opposite from center wing section's and tail assembly ^' s sides for realization a UAV center wing section / fuselage with the tail booms (3) bayonet mount connection and the tail booms (3) with a tail assembly bayonet mount connection. In addition, the L - type cutouts (4) are also perform oppositely to each other between the quick release fastening system's sides, it means that each tail boom (3) has mutually opposite L-type cutout (4) at both ends according to this utility model embodiment, which makes possible to realize a double-sided bayonet mount with the UAV dismountable horizontal stabilizer protected from inadvertent uncoupling due to vibration of a UAV airframe due to bayonet mount from center wing section ^' s side and bayonet mount from tail assembly ^' s side have mutually opposite rotation for mutually fixation. According to this embodiment, the center wing section fixing pins (6) are mounted in the center wing section docking chucks (5) fixedly in a similar way to the tail assembly locking pins (2). The system elements assembly sequence is as follows:

1) connection the UAV wiring bundles connectors (12) from center wing section ^' s side;

2) coupling the tail booms (3) with the center wing section docking chucks (5) and moving them in docking chucks (5) up till stop and rotation of the tail booms (3) in the mutually opposite direction up to the stop for lock of a center wing section bayonet mount;

3) connection the UAV wiring bundles connectors (12) from tail assembly ^' s side;

4) coupling the tail booms (3) with the tail assembly docking chucks (1), so the tail assembly locking pins (2) are coincident with the L - type cutouts (4) of the tail booms (3) and moving the tail booms (3) in the docking chucks (1) up to the stop;

5) rotation of the horizontal stabilizer halves in the direction of their coupling (fig. 7) for locking of a tail assembly bayonet mount.

Outlined claimed utility model embodiments should be considered as particular and possible variants of embodiments that provide equal technical result, described in the application materials.

According but not limited one of claimed utility model embodiment, the UAV structural elements quick release fastening system is used in «PD - 1» UAV design (fig. 9), which is high-wing aircraft with A - type dismountable horizontal stabilizer. The system is used in embodiment with opposite rotation bayonet mount from tail assembly's side, fixing the tail booms from center wing section ^' s side realized using the center wing section fixing pins, which are integral parts of the dismountable UAV outer wings (fig. 8). Two docking plates are used to coupling the horizontal stabilizer parts, which are coupling with the docking chucks (10) of the dismountable horizontal stabilizer and fixing this coupling by the quick release fasteners (11).