Flight Perth Airport departs from Perth Perth Airport at 12:10 and arrives at Singapore Changi Airport at 18:00.
The flighttime is about 5h 50m. The distance travelled ("as the bird flies"): 1789 Km. So the average speed is roughly 307 Km.
The best day to arrive at Perth is Friday and it would be best to avoid Thursday, as prices are on average 113.03% higher than on Friday. (Average prices, based on 266924 datapoints.)
We have a lot more statistics for flights QF 71 and between Perth and Singapore.