>since their bones and joints are relatively weaker and therefore more susceptible to injury. Regular 50-year-olds, sure. But if they find some genetic mutant

>since their bones and joints are relatively weaker and therefore more susceptible to injury. Regular 50-year-olds, sure. But if they find some genetic mutant who looks like he's 25 even though he's 60, and passes all the physical tests as well as a 25-year-old, age isn't going to be a factor. Meanwhile, over in the aviation field, that same genetic mutant would be unable to become a pilot purely because of his age.