I tried a slightly different approach... you draw a line by holding down the left mouse button. When you stop drawing, an airplane is created on the line and follows it.
as the line is drawn, it is divided into a series of "nodes" or segments. Each node knows where to find the next and previous node. (a value of -1 marks the beginning or end of the chain - the plane reverses direction when it hits an end.)
The code is very messy. The plane follows the line exactly as it appears, and sets the plane's angle to the angle of each segment - so the motion is not very smooth. I would want to either automatically smooth the line after it has been drawn, or have the plane smoothly transition from the angle of one segment to the next, and probably would do both... I also briefly thought about having the capx export the node list in json format so that a path could be easily imported into another project for an object to follow.
You can draw multiple lines. There is a speed variable if you want the planes to move faster. There is a lot of room for improvement! : )
you can download the capx here: http://www.rieperts.com/games/forum/follow_line.capx