Flight Taipei Songshan Airport departs from Taipei Taipei Songshan Airport at 08:50 and arrives at Tokyo Narita International Airport at 12:45.
The flighttime is about 3h 55m. The distance travelled ("as the bird flies"): 2229 Km. So the average speed is roughly 569 Km.
The best day to arrive at Taipei is Saturday and it would be best to avoid Wednesday, as prices are on average 238.21% higher than on Saturday. (Average prices, based on 544199 datapoints.)
We have a lot more statistics for flights CI 220 and between Taipei and Tokyo.