A seat system for a passenger aircraft. The seat system includes a passenger seat frame (i) a plurality of spreader bars and (ii) a plurality of laterally extending spar tubes connecting the plurality of spreader bars to one another and at least one canted leg assembly connected to the seat frame for attachment to fixed, spaced apart attachment points on a supporting surface of the passenger aircraft. The canted leg assembly includes: (i) a front leg portion including a front joint clamp for receiving one of the plurality of laterally extending spar tubes in a non-perpendicular attachment point; and (ii) an aft leg portion including an aft joint clamp for receiving another one of the plurality of laterally extending spar tubes in a non-perpendicular attachment point, whereby the seat system is adapted to be laterally positioned and attached to provide different spaced apart passenger seating configurations. A seat back tray table may be attached to the back of the passenger seat frame.