Looking through this thread I suspect all of you who have contributed so far have come up through the civilian route. As a serving army officer I am expected to wear either a cap or a beret depending on the type of uniform I am in at all times except when inside a building. Even then, there are circumstances when I still have to wear it.
As has been pointed out, aviation owes a lot to both merchant and military maritime operations. The uniform looks very similar to that of a deck officer from a merchant fleet. When these uniforms were designed gentlemen wore hats as a matter of course, and one was not considered properly attired unless wearing a hat of some order. This was true even of blue-collar workers. This has carried on into the uniforms of the present day.
Now for my humble opinion. Hats do complete the uniform, in fact that is what distinguishes a pilot from any other man wearing a dark double-breasted suit. The bars worn on the sleve are not always as high-profile as the Navy and so the hat adds a mark of distinction. There is also the issue of public perception. I believe the public expect to see a professional pilot look like a professional pilot, jacket, tie, hat and all. You can argue until you are blue in the face that as a professional you are just as capable of doing the job regardless of what you were. This may be true, however in the eye of the public who fly your airline they expect that a job with such immense responsibility and learning should carry with it the apparrel of authority and rank. Dumbing down dress can only serve to lower the impression that a pilot is no better trained or professional than a sheet metal worker who tips up to his workshop in jeans and trainers. It is the same for officers in the services. No matter how smart my soldiers look, I have to look smarter.
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Remember: all landings are controlled crashes!
[This message has been edited by kbf1 (edited 25 September 2000).]