Flight Brisbane Airport departs from Brisbane Brisbane Airport at 09:15 and arrives at Sydney Sydney Airport at 11:50.
The flighttime is about 2h 35m. The distance travelled ("as the bird flies"): 680 Km. So the average speed is roughly 263 Km.
The best day to arrive at Brisbane is Tuesday and it would be best to avoid Thursday, as prices are on average 111.02% higher than on Tuesday. (Average prices, based on 5496257 datapoints.)
We have a lot more statistics for flights QF 517 and between Brisbane and Sydney.