With jet airliners designed to be flown almost continuously day in and day out under a continuous maintenance program, years of age are meaningless. The most meaningful measure of airliner age is the number ov "cycles." A cycle is basically a trip - a takeoff and landing. Metal fatigue is the primary concern regarding cycles because of the expansion and contraction of the aircraft skin going up to pressurized altitude and then coming back down to earth again. For most aircraft, this isn't a real concern until flying with over 36,000 cycles, after which periodic thorough inspections to detect possible metal fatique are required. The Baltia 747 has about 18,000 cycles, so it has a lot of life left in it. Also it wen theough a thorough overhall recently - called a "C-check". By some measures it was a "deep C check" going beyond C check requirements. So it is in excellent shape.