Actually BKK-SYD-CHC is the longest fifth freedom route operated by the same aircraft. Unless the OP may have meant flights.
To be more pedantic, AKL-MEL/BNE-SIN-CMB-MLE is the absolute longest fifth freedom route even though it's operated by 4 different flights.
Last edited by edy4eva; Jul 16, 2014 at 6:11 pm