Non-sequential reading from magnetic cards possible?

[WrongWay]

Based on the title I thought it might have been an attempt at digitizing a logbook, but its a full blown program, and appears to be a flight planning application. I managed to read 11 of the 12 sides, 5 cards total and only card 1 side 1 gave a MALFUNCTION. The incomplete code is attached. I had to manually transcribe but I double checked the lines and it appears to be correct.