EP0481840A1 - Helicopter landing pad - Google Patents

Abstract

The invention relates to a helicopter landing pad which is easy to transport and to manipulate. It is particularly useful for landing on unconsolidated (movable) ground (desert, dusty ground, snow). It comprises a textile cover-sheet (1) placed on the ground (2). This cover-sheet has eyelets (3) located at its periphery. Stakes (pegs) (4) are driven into the ground (2), traverse the eyelets, and fasten the cover-sheet (1) to the ground (2). <IMAGE>

Description

The invention relates to a helicopter landing pad. It relates more particularly to an area for a helicopter capable of being set up quickly and temporarily.

Although helicopters are likely to land and take off on any terrain, it is useful and sometimes necessary to arrange their landing area.

Such an arrangement is particularly important during landings on soft ground, for example on sand, in the desert. In fact, during a landing on such a terrain, the air displaced by the rotation of the helicopter's blades produces a cloud of sand which envelops the helicopter, impairs the pilot's visibility and produces significant wear of the equipment. Similar phenomena occur when landing on dusty surfaces, or on fresh snow.

Various attempts have already been made to make landing areas very quickly. These areas are made up of rigid or semi-rigid elements assembled on site. These areas are heavy, the elements which constitute them difficult to transport and their relatively long assembly. Reference may be made to document CH-A-373413 which relates to a take-off area of this type. According to document US-A-3 649 724, a deployable landing area transported by aircraft is proposed. This area includes a flexible surface and, around it, inflatable support tubes.

The object of the invention is therefore to produce a light, resistant landing area, the installation of which can be carried out in a very short time and which ensures all the necessary safety and reliability conditions.

To this end, the invention relates to a landing area for a helicopter of the type comprising a flexible sheet and, at its periphery, holding means, which comprises a textile cover placed on the ground, said cover having eyelets located at its periphery. . It also has stakes which have a head and a rod. Each eyelet is crossed by the rod of a stake and retained by its head, this stake being driven into the ground and fixing the tarpaulin relative to the latter.

In a preferred embodiment, the textile cover of the landing area is made of a porous textile which allows the drying of the ground surface under the cover.

Preferably, the textile sheet is produced by weaving strips of extruded polypropylene.

The invention will be described in more detail with reference to the figures in which:

Figure 1 is a general schematic representation of the landing area of the invention.

Figure 2 is a detailed representation of one of the points of attachment of the sheet on the ground.

Figure 3 is a detailed representation of one of the modes of weaving the tarpaulin.

Figure 4 is a schematic representation of a large landing area according to the invention.

FIG. 5 is a detailed representation of the association between them of the elementary covers of FIG. 4.

Figure 6 is a detailed representation of the retroreflectors of the landing area of the invention.

Figure 7 shows a retroreflector in the extended position.

FIG. 8 schematically represents a retroreflector, in its different possible positions.

According to the invention, the landing area for helicopters comprises a textile cover 1 placed on the ground 2.

Surprisingly, it has been shown that under difficult landing conditions, in particular when helicopters land in the desert, the interposition of a flexible textile sheet between the ground and the helicopter in its vicinity makes it possible to '' Significantly improve the safety and comfort of landing without the need for rigid elements or even stiffening elements.

For this, the textile cover 1 is firmly fixed to the ground 2. For this purpose the cover 1 has eyelets 3 located at its periphery. Stakes 4 comprising a head 5 and a rod 6 are introduced into each eyelet 3 and driven into the ground 2. Thus each eyelet 3 is held by the head 5 of the corresponding stake 4 in a fixed position in contact with the ground.

The number of eyelets 3, for a given size of the tarpaulin, the length of the rods 6 of the stakes 4 are determined according to the quality of the soil on which the area is to be used when it can be known by advanced.

In general, it is considered that the distance between two consecutive eyelets 3 is advantageously of the order of 40 cm and that the length of the rods 6 of the stakes 4 is of the order of 40 cm.

The eyelets are preferably metallic and shaped like an opening with an approximate diameter of 1.5 cm.

During the landing and takeoff of the helicopters, the textile sheet 1 is subjected to significant forces, it is therefore preferably made of a resistant material.

The textile which composes it can be woven, knitted or non-woven; it can be coated.

Preferably, this textile sheet 1 is made of a porous textile which allows the drying of the ground surface 2 under the sheet 1. In fact, it has been observed that, taking into account the climatic conditions likely to be encountered, for example in the desert, the deposition of a large surface on the ground is likely to cause the retention of moisture between the soil and the surface and the development of vegetation which deforms or even destroys this surface.

When the textile cover 1 is made of a porous textile, the water accumulated by condensation between the ground and the cover can evaporate and be evacuated when the temperature of the area rises, for example during the day by the sun effect.

Preferably, the textile sheet 1 is produced by the weaving of strips 31, 32 of extruded polypropylene.

Polypropylene gives textile cover 1 its strength and flexibility and lightness. The weaving makes it possible to give the sheet a porosity which avoids the retention of the water of condensation as indicated above.

By way of example, such a textile was used having a density of 165 g / m², having a permeability of 70 l / m² / second, a porometry between 90 microns and 340 microns and produced with extruded strips of approximately 110 TEX.

It is known in itself that during the production of yarns, for example textile yarns, polypropylene is combined with plasticizing, coloring, anti-ultraviolet additives ... It is therefore possible to implement the invention by choosing the color tarp in depending on the context in which the landing area is to be located.

In some cases it will be preferred to choose a contrasting color in relation to the environment so as to allow its easy recognition from a distant distance, in other cases, we will on the contrary look for a color which will blend in with the environment and will make locating the area more difficult.

Preferably, during the implementation of the invention, the lifespan of the landing area is controlled.

To this end, the quantity of anti-ultraviolet additive associated with polypropylene for the manufacture of the extruded strips is dosed to obtain the desired lifespan. This dosage makes it possible, for example, to ensure a lifetime of between one month and one year. In some cases a longer service life is ensured.

In order to ensure the conservation of the tarpaulin over a long storage period, before its implantation, it is packed in a light-tight bag possibly having several thicknesses.

The mechanical strength of the landing area is improved when the textile sheet 1 is hemmed and reinforced. In this case, the eyelets 3 are placed at the hem and are therefore fixed in a triple thickness of the textile sheet 1. Inside the hem is placed a reinforcing strip 7 of polyester fabrics coated with polychloride vinyl.

The textile cover is advantageously square and a dimension of 19.5 m × 19.5 m makes it possible to ensure, under satisfactory conditions of safety and comfort, the landing of small helicopters. The weight of the tarpaulin and its accessories is then of the order of 100 kg, which allows packaging and easy handling.

The realization of a landing area of larger dimension, for example of a surface four times more important is carried out by the association of several elementary tarpaulins 41-44, for example four connected on the spot, during their rest on the ground by lacing known as Lambia 45 lacing.

This type of lacing is shown in Figure 5, Figure 5a shows two elementary covers close together before their association, Figure 5b shows these elements once associated. One of the covering elements 50 comprises eyelets 51, 52 similar to the eyelets 3, a halyard 53 and sewn onto the other covering element 54 so as to form loops 55, 56 whose bases 57, 58 in contact with the cover 54 are intended to come into contact with the eyelets 51, 52. The spacing and distribution of the loops 55, 56 along the edge of the cover 54 therefore corresponds to the distribution of the eyelets 51, 52 along the edge of tarpaulin 50.

When the two covering elements are combined, starting from one end, a loop 55 of the covering element 54 is passed through the eyelet 51 of the covering element 50, the loop 56 is then passed through the eyelet 52 and then in the end of the loop 55 holding the latter in position. The process is then restarted with the next loop to the opposite end of the tarpaulin elements where a knot is formed.

This type of combination of tarpaulin elements allows fast and solid attachment from one to the other. The release of a tarpaulin element relative to the other, during disassembly is very simple.

When the four covering elements 41, 42, 43, 44 are combined, the order of superposition of the edges of the elementary covers is chosen so as to avoid the air vortex catching in the edge of the elementary covers. In fact, the direction of this vortex being constant, the "upstream" elementary cover is always arranged so as to cover the "downstream" elementary cover.

To facilitate the use of the landing area at night, retroreflectors 61, 62 are fixed to each of the corners of the textile cover 1.

Preferably, these retroreflectors are removable, fixed to the textile cover 1 by contact closures 63-66. These contact closures known for example under the registered trademarks "VELCRO" or "APLIX" are each composed of two parts, a velvet and a hook tape, one of these parts is carried by the tarpaulin while the other is carried by the retroreflectors.

According to a particularly advantageous arrangement, these retroreflectors 61, 62 comprise supports 80 carrying retroreflective textile bands 81. Each support consists of four flat 82-85 elements, of elongated shape joined by their ends by articulated links. In the extended position such a reflector therefore has a flat, substantially rectangular shape composed of four elements which can be of identical size, for example 10 cm x 5 cm. The supports 80 of the retroreflectors 61, 62 are for example each made up of 4 rigid or semi-rigid flat elements placed in a canvas gusset sewn at its ends and between two consecutive flat elements. This realization of the joint sought is very simple.

The 4 elements of this assembly, 82-85 carry a part of a contact closure 86. The complementary part of this closure, carried by the cover 71 cooperates with that carried by the retroreflector. A retroreflector 61 can be fixed to the textile sheet 1, in the partially folded position 67-70, having two of their faces approximately inclined 68, 69 at 45 ° relative to the vertical. Thus the retroreflectors 61, 62 are visible from above the area but also from a point remote from the latter (FIG. 7B).

It can be laid flat, it then ensures the visibility of the area only from above (Figure 7A). It can also, in the rest position, be fixed folded back on itself; the retroreflective textile strip 81 is then no longer apparent (FIG. 7C).

Preferably all the seams of the textile sheet 1 are produced with a Tergal yarn.

In its large version, allowing the realization of a square landing surface of 39 m / 39 m the area of the invention is carried out with a set of elements, elementary tarpaulin, stakes, retroreflectors ... the assembly, including the tools various necessary for its establishment can be contained in 4 bags with a unit weight of about 100kg.

Its implantation can be carried out by six people in less than two hours. Once implanted it does not require maintenance.

Claims (9)

Landing area for helicopter of the type comprising a flexible sheet and, at its periphery, holding means characterized in that it comprises a textile cover (1) placed on the ground (2), said cover having eyelets (3 ) located at its periphery and stakes (4) comprising a head (5) and a rod (6), each eyelet (3) being traversed by the rod (5) of a stake (4) and retained by its head ( 5), the stake (4) being driven into the ground (2) and fixing the cover (1) relative to the ground (2). Landing area for helicopter according to claim 1 characterized in that the textile cover (1) is made of a porous textile allowing the drying of the ground surface (2) under the cover (1). Landing area for helicopter according to one of claims 1 or 2 characterized in that the textile cover (1) is produced by weaving strips (10), (11) of extruded polypropylene. Landing area for helicopter according to claim 3 according to claim 3 characterized in that a controlled amount of anti-ultraviolet additive is mixed with the polypropylene so as to give the tarpaulin a lifetime, in the light, of between 1 month and 1 year. Landing area for helicopter according to any one of Claims 1 to 4, characterized in that the textile cover (1) is hemmed and reinforced. Landing area for helicopter according to any one of Claims 1 to 5, characterized in that the textile cover (1) is approximately square. Landing area for helicopter according to claim 6 characterized in that the textile cover (1) comprises four elementary covers (41-44) connected by a Lambia lacing (45). Landing area for helicopter according to any one of Claims 1 to 7, characterized in that it includes retroreflectors (61, 62) for signaling fixed to the textile cover by contact closures, each composed of two parts, one velvet and a hook tape carried respectively by the retroreflectors and the tarpaulin. Landing area for helicopter according to Claim 8, characterized in that the retroreflectors (61, 62) comprise a support (80) carrying retroreflective textile strips (81), the support comprising four elongated flat elements (82-85), fixed to each other by a link articulated at their ends, carrying part of a contact closure (86).

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