Composite fan containment case assembly

Abstract

A fan case for a gas turbine engine includes a composite fan containment case that includes an outer surface. The composite fan containment case includes multiple composite layers that define a generally cylindrical case. An attachment flange extends radially outward from the cylindrical case. The attachment flange comprises a portion of the composite layers. A metallic backing ring is secured to the attachment flange by rivets.

1 . A fan case for a gas turbine engine comprising:
 a composite fan containment case including an outer surface, the composite fan containment case includes multiple composite layers defining a generally cylindrical case, an attachment flange extending radially outward from the cylindrical case, the attachment flange comprising a portion of the composite layers, and a metallic backing ring secured to the attachment flange by rivets.   
     
     
         2 . A fan case for a gas turbine engine comprising:
 a composite fan containment case including an outer surface, a front and a rear;   an attachment flange and a mounting ring respectively provided on the front and the rear, the mounting ring is metallic and is secured to the outer surface at the rear, the mounting ring includes a failsafe lug and primary lugs extending radially outward and circumferentially spaced from one another, the lugs configured to secure to an engine mount beam connected to a pylon; and   fan exit guide vanes secured to the composite fan containment case by fasteners arranged on either axial side of the primary lugs.   
     
     
         3 . The fan case according to  claim 1 , wherein the rivets include heads that do not protrude from the metallic backing ring. 
     
     
         4 . The fan case according to  claim 1 , wherein the attachment flange and metallic backing ring respectively include a first and second sides, and each rivet includes first and second heads respectively engaging the first and second sides and clamping the metallic backing ring to the attachment flange. 
     
     
         5 . The fan case according to  claim 4 , wherein the first head does not protrude from the first side. 
     
     
         6 . The fan case according to  claim 5 , wherein the first head is flush with the first side. 
     
     
         7 . The fan case according to  claim 4 , wherein the second head does not protrude from the second side.