Well, gosh, being both female and flying I guess I’ll just wade in here.
First mentioned in the thread - cost of flight school. Getting your private license - first step on the ladder - costs about $6,000. Then you need an instrument rating, commercial, and usually you get a flight instructor rating in there too. Then you need to get experience in multi-engine aircraft, little jets, big jets… some of those planes cost several hundred dollars (or more) an hour to rent - and you need more than just a few hours.
Yep, the training required to become an airline pilot is extremely expensive. But that affects men and women equally, so I don’t think that’s it. It’s costs lots to become a doctor, too, but there’s a higher percentage of female docs than female pilots.
OK, let’s talk about growing up in society. When I was 7 years old I went into a hobby shop to buy a model airplane. I got laughed at and told “girls don’t fly planes!” Unlike boys, who are encouraged to do these things. Yes, I think this has some effect on the numbers of women getting into aviation. On the plus side, when I go into hobby and model shops these days I actually do see girls there and no one laughs at them any more.
Let’s talk about the rest of society. My experience as a female pilot has largely been one of acceptance by my fellow (male) pilots. However, girlfriends and wives of my flying buddies are frequently extremely hostile towards me. I don’t know why - I might steal their husband’s airplane, but certainly not their husband! I run into what I call “tourists” who say things like “Oh - your husband is a pilot and you ride with him, right?” (Uh, no - I’m the pilot. He’s too busy taking pictures of scenery to bother with it) “You here with your boyfriend?” There have been people who watch me land, get out of an airplane that obviously has only one person in it, then state flatly that they don’t believe women can fly. Oh, and one of my “favorites” - “you’ll stop doing that when you have kids, right?” Like it’s somehow more acceptable for a father to kill himself in an airplane than for a mother to do so (which is usually what seems to be implied). I just love the line “you don’t LOOK LIKE a pilot!” (And your point is…?) And, oh yes, I get accused of being a dyke fairly often - I suppose under the assumption that women who like to play with heavy machinery are butch, macho, and lesbian. Fortunately, both my husband and I have a good laugh over those comments. I hear folks on airlines expound at length about how relieved they are it’s not a woman flying the plane. Yes, I think that has some effect on women going into aviation.
Flying is still perceived as risky. Women, in general, are less inclined to do risky stuff than men. Is this society or biology? I don’t know, I just know that right now it is. Fewer women are the necessary sort of “risk-accepting” personality required for flying. Yes, I think that affects the numbers, too.
The military angle used to be a significant factor - although there have been women military pilots since WWII, most military pilots have been and are men. When most airline hires were military, that definitely skewed the stats. Now, however, 60% of new airline hires are strictly civilian trained. And there there are more women flying for the armed forces than ever before. So this is much less a factor now.
There is also an “oogy” factor - you wind up with a certain amount of grease on your hands. Sounds dumb, but some women just don’t want to get their hands dirty. Me, I just spent 2 hours at the airport tonight helping a mechanic take care of a gas tank problem - sometimes that’s what it takes. More guys do their car repair work than women - why is that? Whatever the reason(s) is - that’s one more factor. If you want to be a pilot you have to learn something about the mechanics of how things work. I’m amazed at how many women think they can’t do that. Sure they can, it’s not rocket science! (For that matter, there are female rocket scientists, too)
I started flying in ultralights. Men to women ratio: 400:1 Now I’m in general aviation - 20:1 I heard that as many as 1 in 12 commercial pilots are female - in which case they have a higher representation among the professionals than among non-professional pilots. There’s no question (among pilots) that women are just as capable, and in fact statistically we are less likely to get into an accident. There’s also no question there are fewer of us than men. I think one reason a lot of the women who fly do it for living is because they are more driven than men - there’s a lot more crap we get from society for choosing that path, so the only ones who stay the course are the truly gonzo.
Me, I’m happy to keep it as a hobby, at least for now. But so what? I have a blast.