Why spend billions upgrading old F-15C's when the line is still open (last one not due for completion until 2019) so why not just continue the line and build a new batch of F-15X for want of a better term and replace/retire all the old shagged out existing F-15/16 fleet with a mix of these new build and F-35 to supplement the F-22...??
Although I guess the running costs of the 16 is somewhat less than the 15..?
