I'm just curious whether the Cargolux crews fly for a while in just two or three time zones or do they fly only very long haul each leg, east and west? Do their layovers allow them at least two days to adjust to local time?
One of our FOs has a wife who is an MD-11 FO at FEDEX, and their pilots can supposedly refuse a trip sometimes due to fatigue from severe "body clock" disruptions, after returning from Narita, Emirates etc.
Our 747 pilots who return from days in the Pacific Rim are told to avoid major personal decisions for about three days. After years of this flying, long-haul pilots seem to age faster than the domestic crews.