The Boeing Company
Structural composite airfoils with a single spar, and related methods

Abstract:

Structural composite airfoils include a primary structural element and a secondary structural element defining a trailing edge of the structural composite airfoil. The primary structural element includes an upper skin panel, a lower skin panel, and a middle C-channel spar that is coupled to the upper skin panel and the lower skin panel. An upper flange of the middle C-channel spar is coupled to the upper skin panel, while a lower flange of the middle C-channel spar is coupled to the upper skin panel and the lower skin panel. An internal volume is defined by the upper skin panel and the lower skin panel aft of the middle C-channel spar, and is defined by the upper skin panel forward of the middle C-channel spar. The leading edge region of the primary structural element defines the leading edge of the structural composite airfoil.