Patent ID: 8807924

Claim:
A fan blade comprising: a main body extending between a leading edge and a trailing edge, and channels formed into said main body from at least one open side with a plurality of ribs extending across the main body intermediate the channels, with said fan blade having an airfoil extending radially outwardly from a radially inner end; said channels having a termination end adjacent a radially inner end of the ribs, and said termination end being formed along a complex fillet with a first radius of curvature portion formed along a first radius of curvature and at the termination end, and a second radius of curvature portion formed along a second radius of curvature and merging into sides of the ribs, with said second radius of curvature being greater than said first radius of curvature; and a skin closing off said channels with a first radius of curvature portion formed along a curve and the second radius of curvature portion also formed along a curve and merging from said first radius of curvature portion and into sides of the ribs.