If you leave kids to their own devices it's interesting how the girls go for the dolls and dress ups and the boys want to go and play with the trucks and diggers. Feminists can say what they like but anecdotal evidence would suggest otherwise. Why do Lego now have girl focused Lego which is more about relationship rather than just the usual Pirates/Towns/Spaceship etc.
Not saying girls can't be good LAMES or Pilots but when talking about large numbers of people the average tends to sway toward the societal norms, which is what makes this 50% business a bit ridiculous. Then add into that becoming an airline pilot takes alot of sacrifice regardless of gender and that airline jobs are really very competitive anyway.