The center wing is attached to the frames and to the keel longerons at the bottom of the fuselage middle part. The center wing is made from a wing box structure with skin panels on the top and bottom. The center wing is sealed between the front spar and rear spar and the rib at WS35.60 to make the integral fuel tank. The center wing is attached to the frames and to the keel longerons at the bottom of the fuselage middle part. The center wing is made from a wing box structure with skin panels on the top and bottom. The center wing is sealed between the front spar and rear spar and the rib at WS35.60 to make the integral fuel tank.

The center front spar extends between left and right WS35.60. It has a splice on the outer front spar to make a one piece assembly that extends between the rib assemblies at left and right WS356.47. The center front spar is made from machined aluminum alloy that includes the stiffeners and the caps.

The center rear spar extends between left and right WS35.60. It has a splice on the outer rear spar to make a one piece assembly that extends between the rib assemblies at left and right WS356.47. The center rear spar is made from machined aluminum alloy that includes the stiffeners and the caps.

The rib assemblies consist of five shear web-type ribs at BL0.00, BL20.00, and WS35.60. They give the contour to the wing skin panels. The ribs are made from machined aluminum alloy that includes the stiffeners and the caps. The collector tank panels are installed between ribs BL0.00 and BL20.00 in the left and right sides of the wing. The panels divide the fuel tank into two compartments at each side. The collector fuel tank is in the aft side of the collector tank panels of the center wing.

The wing skin panels for each wing extend from the center of the wing BL0.00 to the wing tip.

Two wing-to-fuselage attachment fittings are found on the center line of the front and rear spars at the forward and aft ends of the BL0.00 rib. The forward fitting attaches the wing box structure to the fuselage keel longerons. The aft fitting attaches the wing box structure to the keel and lateral beam of the fuselage. Two front side fittings are installed on the front spar, BL31.90 at each side of the center wing. Two rear side fittings are installed on the rear spar, BL33.20 at each side of the center wing. Two side shear web chords are installed on the upper surface, BL35.25 at each side of center wing. All of the wing-to-fuselage attachment fittings are made from machined aluminum alloy.

The MLG side stay fittings are made from hand-forged aluminum alloy. They are installed between the aft fitting and the rear side fitting on the rear spar with the extension fittings.