Every six months one gets put into the pinball machine and checked; every six months there's the flight physical including EKG; annual line check and annual recurrent groundschool. Some guys retire early, some stay till FAA mandatory retirement age 60. Some move back to the F/E seat and work another 10 years, or until they fall out of their chair. We have one F/E (ex captain) at age 72 who is still kicking the tires. One thing is for sure, he doesn't need the money. Maybe it's because he likes the job so much, or maybe it's because he needs to get away from the wife now and then.
There are old pilots and there are bold pilots, but there are no old bold pilots.