If I remember right, one of the 'Tips' tutorials Maya comes with (not one of the beginning ones - there's a whole bunch of other tutorials or 'how-tos' scattered throughout the documentation) covers the question of how to get animation to/from motion paths.
Other than that, I'd reccommend attaching the hind to both the platform and the motion path with a parent contraint (well, you probably need to attach a curve to the motion path, then parent constraint to that). Then, to animate moving between the two, simply change the weighting between the two different parent constraints. You should be able to get the helicopter to point 'along' the path by attaching another obect to the curve at a different u-value, and giving it an aim constraint.