Air Canada hired people in their 40s but with already a good amount of experience. You need a good 5 to 6 years flying 600/700h a year to get there.
But anyway, I do agree that it's never too late and that he should go for it as long as he understands what is the road to the airline made of.
Good luck to you Coug and keep us posted!
M.
p.s: yes I know, 39 + 6 = 45!