Thunderbird 5 had radio problems and had to land early. That left only 5 Thunderbird planes to finish the show. Notice that they were already using a backup plane, the two-seater, in the show because the original plane number 4 wouldn't start for the show.

Thunderbird 5 had radio problems and had to land early. That left only 5 Thunderbird planes to finish the show. Notice that they were already using a backup plane, the two-seater, in the show because the original plane number 4 wouldn't start for the show.