Flight Taoyuan International Airport departs from Taipei Taoyuan International Airport at 08:15 and arrives at Hong Kong Hong Kong International Airport at 10:05.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 826 Km. So the average speed is roughly 451 Km.
The best day to arrive at Taipei is Saturday and it would be best to avoid Sunday, as prices are on average 143.71% higher than on Saturday. (Average prices, based on 3430757 datapoints.)
We have a lot more statistics for flights BR 851 and between Taipei and Hong Kong.