Sail wing aircraft which includes an engine mounted on a pylon

Sail wing aircraft which includes a wing (6) and at least one propulsion engine (8). It includes an upper beam (22) which is firmly fixed at its front end to a first frame (12) located on an air inlet (14) of the propulsion engine and which is in addition firmly fixed at its median part to a second frame (16) located to the rear of the first frame. The sail wing aircraft includes in addition a pylon (26) for attachment of the engine onto the fuselage, where the engine is fixed to the pylon (26).

The invention relates to a sail wing aircraft which includes a wing and at least one propulsion engine.

Sail wing aircraft are so called because of their overall appearance which, in aerodynamic terms at least, does not allow a clear distinction to be made between the fuselage and the wing, as is the case with conventional aircraft which are made up of a cylindrical fuselage to which the wing is added. Document FR 2 909 358 describes a sail wing aircraft of this type.

The subject of the present invention is a sail wing aircraft of this type which includes an original engine attachment system.

This aim is achieved, according to the invention, by the fact that the sail wing aircraft includes an upper beam which is firmly fixed at its front end to a first frame located on an air inlet of the propulsion engine and which is in addition firmly fixed at its median part to a second frame located to the rear of the first frame, with the sail wing aircraft including in addition a pylon for attaching the engine to the fuselage, to which pylon the engine is fixed.

Advantageously, the sail wing aircraft includes a third frame located to the rear of the second frame.

The sail wing aircraft generally includes a fan cover hinged on the upper beam between the first and second frame.

Again, the sail wing aircraft generally includes a thrust reverser cover hinged on the upper beam to the rear of the second frame.

The pylon advantageously includes two points for attachment of the pylon to the fuselage at its front end, two points for attachment of the pylon to the fuselage in its median part and one point for attachment of the pylon to the fuselage at its rear end.

In one construction option the pylon includes three points for attaching the engine to the pylon at its median part and two points for attaching the engine to the pylon at its rear end.

In addition the invention relates to a procedure for mounting a propulsion engine onto a sail wing aircraft, characterised by the fact that:

a cut-out is provided in the fuselage;

an upper beam is provided above the cut-out in the fuselage;

the engine is pre-assembled on a support pylon;

the assembly formed by the engine and the support pylon is hoisted up through the cut-out in the fuselage by hooking onto the upper beam;

the pylon is fixed onto the fuselage;

the assembly formed by the engine and the support pylon is released from the upper beam so that there is no longer any mechanical link between the upper beam and the propulsion engine after the assembly formed by the engine and the pylon has been hoisted.

Represented inFIG. 1is a perspective schematic view of a sail wing aircraft2. The latter is made up of a fuselage4and two wings6. As has been explained, there is no clear distinction between the fuselage4and the two wings6. Similarly, the sail wing aircraft has no conventional tailplane, which on most aircraft with a fuselage is fixed to the rear part of the fuselage.

The engines8, which are for example three in number, are fixed to the upper wing surface10of the sail wing aircraft. The engines8are fitted in a “semi-recessed” manner.

Represented inFIG. 2is a perspective view showing the upper beam. The sail wing aircraft includes a first frame12mounted adjacent to an air inlet14of the engine as well as a second frame16, and, in the example shown, a third frame18. Frames16and18span a cut-out20in the fuselage4of the flying wing aircraft. An upper beam22is fixed to the first frame12, to the intermediate frame16and to the third frame18. The beam22includes fixtures24also known as bootstraps. These fixtures24are used for hoisting the engine through the cut-out20. They are removable and are removed once hoisting has been completed.

Represented inFIG. 3is the engine8ready to be hoisted. The engine has been pre-assembled with the pylon26. Using a handling truck28the assembly formed by the engine and the pylon is brought beneath the cut-out20made in the fuselage4of the sail wing aircraft. The engine-pylon assembly is fixed to the fixtures24and the engine is then hoisted until it occupies its final position. The pylon is then fixed onto the fuselage. Once this operation has been completed the assembly formed by the engine and the support pylon is released from the upper beam so that there is no longer any mechanical link between the upper beam22and the propulsion engine8after the assembly formed by the engine and the pylon has been hoisted.

FIG. 4is a perspective view which shows the covers hinged on the upper beam22. These covers are, respectively, a fan cover30and a thrust reverser cover32. The fan cover30is hinged on the upper beam between the first frame12and the second frame16, whereas the thrust reverser cover32is hinged between the second frame16and the third frame18. In this figure the semi-recessed configuration of the air inlet14can also be observed.

Represented inFIG. 5is a perspective view of the pylon26. The latter is made up of a box structure. It is made up of panels34, onto which are fitted ribs36arranged perpendicularly to the panels34. The pylon has a narrower front part38and a wider rear part40. There is a column42at the rear of the part40. A spar44connected to the rear part40of the pylon26stiffens the column42. The pylon26includes fittings allowing it to be fixed to the fuselage of the sail wing aircraft. At its front part it includes a fitting46which bears the longitudinal forces48and transverse forces50. It also includes a fitting52which bears the vertical forces54. At the transition part between the wider part40and the narrower part38the pylon includes two fittings56arranged symmetrically relative to a plane of symmetry of the pylon. The fittings56bear the vertical forces, as shown schematically by the arrows58. Finally, at the rear end of the pylon, there is a fitting60which bears the transverse forces62as shown schematically by the arrow.

In addition to the fuselage attachment points, the pylon includes engine attachment points used to fix the engine firmly to the pylon. These attachment points are made up of two attachment points63arranged symmetrically in relation to a longitudinal plane of symmetry of the pylon and located, longitudinally, at the transition between the narrower part38and the wider part40.

Link rods62are fitted on the column42. These rods are fixed to the engine. They exert a resultant force64on it. To the rear of the engine there are also points at which the engine is fitted onto the pylon. This fixing is brought about by means of a fitting (not shown). These points of attachment respectively bear the forces designated by references66,68and70.

Represented inFIG. 6is a view showing the engine in its installed position. In this position the pylon26has been fixed to the structure of the sail wing as explained with reference toFIG. 5. The engine is fixed only to the support pylon26with no fixings to the frames12,16and18. At the bottom of the median part of the engine, note two points72for attaching the engine to the pylon using a fitting (not shown). The third point of attachment is in waiting. To the rear of the engine, note two points74for fixing to the column42of the pylon26using a fitting (not shown).

The presence of a device designed to ensure safety in the event of a component failure will also be noted. There is a fitting between the frame16and the engine. Under normal conditions there is no contact. In the event of failure of any of the engine support elements, the engine could fall. Thanks to this device, also known as a “fail-safe” device, the engine is stopped on this waiting fitting.