after max a year on type LHS.
Minimum 200 hours or completion of their probation (six months) - whichever is later.
I recall there were issues in the past when JF/O's were on the Tristar and Classic fleets as they were wound up. They required "special" conversions since they were JF/O's and not F/O's. But apparently these days, JF/O is just a Company rank. So in theory, a successful JF/O initial line check could immediately be followed by a conversion course.