ANA1/ANA2 are 777-300ER flights between NRT and IAD.
ANA1 IAD-NRT shows up on FA as "773"
ANA2 NRT-IAD shows up on FA as “77W”
What is the possible reason for this? Is it because there are different (airline) dispatchers filing the flight plans with different equipment types? The 773 and 77W are fairly consistent on the respective flights (for the last couple of weeks at least).
Thanks in advance for the explanation.