I would imagine around 8-10 years. Previous command experience does not get you any further up the list. Believe minimum hours for command are 6000, with 250 hours credit given for each year in Virgin up to a maximum of 1000 credit. With 8-10 years in the right hand seat most will easily achieve that 6000 hours. That said, there are far worse places to spend your time in the right hand seat!