Right now we have several pilots that are over 60 and are flying as PIC. Thye were flying SIC up until about a year ago when the ICAO rules changed. They have special pairings built that don't fly into or over the US (how they manage that reamains a mystery). As far as retirements go, I would think that they will be slow for the next 10 years and then pick up drastically unless the stock goes above $30 then retirements will be rather big.