n the First World War most airplanes did not even have an enclosed cockpit. While serving in France and Belgium, the Royal Flying Corps pilots had already begun wearing long leather B3 bomber jackets in 1915, and the trend caught on. The US Army established the Aviation Clothing Board in September 1917 and began distributing heavy duty leather flight B3 bomber jackets; with high wrap around collars, zipper closures with wind flaps, snug cuffs and waits, and some fringed and lined with fur. Thus, the American flight B3 bomber jacket was born.

During WWII, sheepskins were originally designed to keep bomber pilots warm in unpressurized cabins at altitudes over 30,000 feet. With a loss of 3°F for every thousand feet of altitude, the W.W.II pilots and bombardiers flying at 30,000 feet in the middle of winter needed a seriously warm coat, the B3 Bomber Jacket.