The Flex Track Drill is a lightweight, portable, automated machine used to drill aircraft structure. It is a low cost option to traditional automation where large 4 or 5 axis machines are normally used. The Flex Track Drill utilizes two flexible rails vacuumed to the part. Mounted to the rails is a carriage that carries a drill spindle that is driven in two axes. The rails are designed to be stiff and accurate in one plane and flexible in the other. The rail design allows the system to self-normalize and simplifies part programming - the machine uses 2D flat pattern programs. The Flex Track Drill uses local index holes for reference and does not rely on “global” accuracy. Those reference holes can be drilled by hand using the supporting structure as a reference or can be machine drilled using a conventional NC (numerically controlled) machine. An additional benefit of the Flex Track is that one machine can be used to automatically drill many different part shapes and contours in areas that are difficult for conventional machines.