An airborne body comprising a shutter mechanism for covering a wing's (32, 34; 232, 234; 732, 734) spreading opening that comprises at least one flap assembly, wherein from the instant that a deployed wing (32, 34; 232, 234; 732, 734) of said airborne body passed and moved over it, it is biased by traction of at least one springy element to an angular motion around an axis, to a condition where a flap component of said assembly is positioned such that it is substantially conformal to the outline of the outer surface of the fuselage of said airborne body and while it covers said deployment through which the wing (32, 34; 232, 234; 732, 734) passed in its motion; and from an instant that said wing (32, 34; 232, 234; 732, 734) returned and connected to said flap component of said assembly, the flap component is biased to an angular motion counter said spring, to the state that said wing (32, 34; 232, 234; 732, 734) returns and is relocated on its top surface; wherein said mechanism comprises an array of plurality of said flap assemblies that are installed in series one next to the other, in a manner that enables a covering that tracks the varying lengths of said deployment, in accordance with the state of said wing (32, 34; 232, 234; 732, 734) deployment and an elongated component to be installed in parallel to an edge of said wing's (32, 34; 232, 234; 732, 734) deployment; and wherein each of said flap assemblies comprises a tab component (212, 512) that constitutes said flap component of the assembly; and a bracket component to axially install said tab (212, 512) on it, in a manner that enables said tab (212, 512) to move in an angular motion as said, from a state wherein said tab (212, 512) is tangent in its direction to said bracket to a state in which said tab (212, 512) is orthogonal in its direction to said bracket in an angle of approximately 90°; and wherein said bracket component is installed on said elongated component in a manner that it is tangent in its direction to said wing's (32, 34; 232, 234; 732, 734) deployment; and a plurality of springy elements that are mounted between said bracket and said tab and regularly bias said tab to motion to the tangential state in which it covers said wing's (32, 34; 232, 234; 732, 734) deployment, but enables propelling said tab to an angular motion to said orthogonal state counter said spring's stress, from the instant that said wing (32, 34; 232, 234; 732, 734) returned and connected to contact with the tab and biases said tab to an axial motion counter said springs, up to a state in which the wing (32, 34; 232, 234; 732, 734) returns and becomes located on said tab. from the instant that a deployed wing (32, 34; 232, 234; 732, 734) of said airborne body passed and moved over it, it is biased by traction of at least one springy element to an angular motion around an axis, to a condition where a flap component of said assembly is positioned such that it is substantially conformal to the outline of the outer surface of the fuselage of said airborne body and while it covers said deployment through which the wing (32, 34; 232, 234; 732, 734) passed in its motion; and from an instant that said wing (32, 34; 232, 234; 732, 734) returned and connected to said flap component of said assembly, the flap component is biased to an angular motion counter said spring, to the state that said wing (32, 34; 232, 234; 732, 734) returns and is relocated on its top surface; wherein said mechanism comprises an array of plurality of said flap assemblies that are installed in series one next to the other, in a manner that enables a covering that tracks the varying lengths of said deployment, in accordance with the state of said wing (32, 34; 232, 234; 732, 734) deployment and an elongated component to be installed in parallel to an edge of said wing's (32, 34; 232, 234; 732, 734) deployment; and wherein each of said flap assemblies comprises a tab component (212, 512) that constitutes said flap component of the assembly; and a bracket component to axially install said tab (212, 512) on it, in a manner that enables said tab (212, 512) to move in an angular motion as said, from a state wherein said tab (212, 512) is tangent in its direction to said bracket to a state in which said tab (212, 512) is orthogonal in its direction to said bracket in an angle of approximately 90°; and wherein said bracket component is installed on said elongated component in a manner that it is tangent in its direction to said wing's (32, 34; 232, 234; 732, 734) deployment; and a plurality of springy elements that are mounted between said bracket and said tab and regularly bias said tab to motion to the tangential state in which it covers said wing's (32, 34; 232, 234; 732, 734) deployment, but enables propelling said tab to an angular motion to said orthogonal state counter said spring's stress, from the instant that said wing (32, 34; 232, 234; 732, 734) returned and connected to contact with the tab and biases said tab to an axial motion counter said springs, up to a state in which the wing (32, 34; 232, 234; 732, 734) returns and becomes located on said tab.