The wing

The wing of Bourane consists of 2 parts (right-hand side and left) which form a delta wing. Each half-wing has a angle located at the first third, the principal surface of the trapezoid is 250 m2 for a scale of 24 m. The middle part of the wing is ensured by the fuselage. The mechanical loads of the bearing pressure are reported towards it.

The structure of the wing is divided into several parts, the nose, the average part, the tail, the landing gear compartment, its trap door and the elevons. The structure of each wing include panels of reinforcement and the central girders.

Structure of the BTS-002 wing

The nose of the wing includes 22 sections shaping the open envelope in nose cone arch, and covered by a heat shield containing carbon. Over the entire length of the nasal part are fixings which firmly holds it with the fuselage. These last play also the part of heat insulator (the bolts have insulating screw).

The leading edge consists of 68 tubular membranes and connections. In the rear part of the leading edge is a opening round to allow the fixing of the first section of the nose of the wing, the lid is tightened then by bolts protected by a flexible joint. Moreover the leading edge of the wing is covered by a heat shield containing carbon to protect from heat during the re-entry in the atmosphere which can reach until 1600°C.

The rear part of the wing (from the leading edge to the landing gear compartment) includes 7 central girders, the higher panels and inferiors are made of undulated metal based on aluminium. The first and seventh central girders are the principal beams, the others are connected by cross beams and held by bolts and tubes made of titanium alloy.

The middle part of the wing, from the first central girder of the compartment to the last central girder of the wing, contains 14 reinforcements linked by the higher and lower panels of the structure. The strengthening pieces rigidify the structure in order to support the transversal components of the constraints and include dismountable sections. Between the 2 last central girders are located the radio antennas protected by radiotransparentes trap doors.

The rear part of the wing is laid out after the last central girder and contains the attachment pieces and the mechanisms for the elevons.

The protective shields of the elevons include 16 sections. These plates of protection (see the photo on the right) move along a "rail" thanks to a carriage and a roller connected to the traction system of the elevon. This mechanism ensures an optimum protection and a synchronous movement between the elevons and the plates of protection except on the slit along the contour of the wing where the plasma can infiltrate.

During the descent in the atmosphere, the maximum temperature on surfaces of Buran is reached on the slits and the joints of the various elements of the aerofoil. This is why the objective of reduction of the slits between the various elements of the structure at the design time of Buran was a very important point. The engineers succeeded in solving the problem, in particular hiding 2 slit connections, present on almost all planes model:

• removal of the slit between the skittle and the rudder by a special cap;
• by the design and use of special plates (on the upper surface), for protecting fixings of the elevons (on lower surface) and to prevent plasma from being in contact with the wing;

The landing gear compartment of rectangular section is limited by 2 central girders of reinforcement, a strengthening piece and the fuselage. The trap door in closed position is pressed on the frame of the compartment and remain closed thanks to bolts. The tightness of the compartment is ensured by a double caulking.

The connection of the wing to the fuselage is carried out using central girders, to which hole head bars are attached, whereas on the edges of the fuselage the nodes of fixings are pins. The welding between the fuselage and the wing is carried out by an aluminium alloy. Moreover the structure of the wing is relatively hermetic because all the weldings are continuous.

Blueprint of the wing:

Wing schematic 1

Wing schematic 2

Wing schematic 3
Nose of the wing
Protection of the wing
Middle part of the wing
Upper panel
Central girder N6
Central girder N8
Strengthening piece
Strengthening piece N1
Strengthening piece N2
Strengthening piece N2
Strengthening piece N3
Strengthening piece N3