You may want to have the 2 primitive sets:

CITY

e.g. CHI MNN KC_

and
 PERIOD or event points

e.g. P0600 P0630 P0700  etc.

The nodes of the network will be the 2-tuples
    (i,p) or (CITY, PERIOD)

The arcs/decision variables will be:

   x(i,p,j,q) = planes flying from (i,p) to (j, q)

Additionally you want the idle on ground arcs:

   idle( i, p) = planes idle on ground at i just after point p,

The flow balance constraints will be essentially, for each (i, p):

   idle( i, p-1) + planes arriving at (i,p) = idle( i, p) + planes departing (i,p)

The demand constraints for each (i,p,j,q) will be something like:

  capacity flown on (i,p,j,q) >= demand( i,p,j,q).

Send me an email and I can send you runnable code for your specific data set.