So if each flier is on 4 x 120ft = 480 ft.

There are 36 fliers so 480 x 36 = 17,280 ft.

There are 5,280 ft in a mile if my memory serves me correctly so that make 3.27 miles of line.

With 54 fliers, 480 x 54 = 25,920 ft which is 4.9 miles.

With 100 fliers, 480 x 100 = 48,000 ft which is 9.1 miles.

Quite a lot of string!