1. Skecth 3in circle and extrude to 0.08in on front plane.
2. Skecth 0.6in circle on top extruded face and exrude to 1.5in.
3. Sketch fin profile at extruded face as shown and extrude to 0.6in.
4. Add Plane 1 with 0.68in offset from Front plane and Plane 2 with 0.85in from Plane 1.
5. Insert sketch on Plane 1, select all edges to extruded fin and convert it to entities.
6. Insert another sketch on Plane 2, as shown.
7. Sketch two curve line using 3D sketch tool, as shown.
8. Click Lofted Boss/Base , select profile Sketch 5 and sketch 6 and for guide curves select 3DSketch1 and 3DSketch2 , OK.
9. Click Circular Pattern , view temporary axis Tools>Temporary Axes. Select center axis, 360 degree, #8, Equal Spacing, OK . Done!