In scene 7 (Lack of Oxygen), the Vulcan airplane first has the call-sign KKT5-6 (kilo kilo tango 5-6) (at total DVD playing time 00:26:05). A minute later (playing time 00:27:16 and 00:27:25), it is been given the call-sign MBX7-9 (Mike Bravo X-ray 7-9).