left seat for aegean is minimum 5 years airline experience flying jets,and 3000 hours b737 as an aegean f/o.Then if they think you are ready you can go for upgrade.Safety for aegean comes first thats why they really want to have high experienced captains.I believe that with this way a f/o upgrading is really ready and has the skills needed for this high demanding job.Take care guys,have happy landings.