I have trained many men and women in the fine art of flying (and the finer arts of air-to-air refuelling and low-level operations) over the last 15 years. I concluded long a go that there is no significant difference in intrinsic ability between the two sexes in this field. There is, as Prune Towers so eloquently said, a vast difference in expectation. I don't have the definitive answer as to why that should be, but I suspect that much of it is down to peer pressure between 13-18 years of age. Perhaps Sally and Oleo would care to comment on how many of their female school acquaintances fully supported them as opposed to the number that said 'you'll never do that'?
Having said that, things do appear to be improving. There is far less real prejudice around than some would have you believe, and gradually the number of women that aspire to traditionally male careers is increasing. I hope that in 5 or 10 years time this subject would never come up!