Why do pilots wear a uniform?
Airline pilots wear uniforms to make them instantly recognizable when at the airport or on the plane. The flight crew is responsible for the aircraft and therefore must command respect and authority from passengers and co-workers.
Pilot uniforms are generally similar in design to some military Officer uniforms as traditionally, military and commercial aviation share the same heritage. Each airline has a unique uniform design for its pilots, some more subtle than others, although they are clearly generally similar in composition.
They are worn for several reasons:
It is important that the flight crew and their rank can be easily identified by passengers and staff, whether in the terminal or on board the aircraft. Whether through first-hand experience or through exposure to the uniform in the news, movies or pictures, almost everyone has a good idea of what a pilot’s uniform looks like, what makes them immediately recognizable.
The flight crew may need to issue urgent safety-related instructions. If a person appears to have a high level of authority, the instructions issued are more likely to be followed.
The traveling public rightly expects its pilots to operate to the highest professional standards. Flying is a safety-critical industry where passengers need to be reassured that everything associated with flying an aircraft is done professionally and to a high standard.
Projecting a professional image by looking smart and presentable helps reassure passengers of the professional standards of flight crews. If a pilot looked scruffy with his unironed shirt, loose tie with the top button undone and not well groomed, how would that make you feel about his professional standards?
You want your pilots to be on top because consciously or unconsciously their uniform standards will reflect their general level of aircraft operation.