The flight jacket, more commonly called the bomber jacket, is a well insulated style of jacket originally created for use by pilots during world war one. The purpose of these jackets was to keep the pilots warm in the uninsulated cockpits of their plains; where it was not uncommon for the temperature (at the upper altitudes) to drop to -50 degrees Fahrenheit.
The first true bomber jacket took its inspiration from long leather coats worn by the British air force for much the same reason. Bomber jackets, while diverse, tend to follow some of the same design principals, namely: thick leather construction, wind flap covered zippers, wraparound collars, tight cuffs and snug fitting waste lines. It is also common to find bomber jackets lined with fur.