Would 'η πτήση αρχίζει στο πρωί' work here?
Αρχίζω means to begin something. For starting to move, ξεκινώ is used.
To add to troll's comment, even if the verb worked in this case, it would be followed by "το", not "στο".
Nice one, many thanks to you both for explaining. I think I'd originally learnt both words as meaning 'start', but now you've explained it that way I can see the 'κινώ' in there and it's perfectly obvious.
Why is "στο" incorrect here?