The original bomber jackets designed for bomber pilots in the Second World War came in different styles identified by the United States Aviation Clothing Board by code numbers. Two of the most popular types were the A-2, designed for the Air Force and the G-1, designed for the Navy and Marine Corps bomber pilots. Then came shearling jackets , which were lined with sheepskin. All the pilots had to have one because they were so warm and well insulated, and they were flying at 30,000 feet in the middle of winter in open cockpits. 
There were various styles ranging from the B-3 shearling bomber jacket to the M-455, also a Navy jacket. Of all these sheepskin bomber jackets, the B-3 is considered to be the military classic. Not only were they worn by the bomber pilots, but also by non-flying officers who liked its stylish looks and found it to be incredibly comfortable. Of course it wasn't long before the same style had made it into commercial factories along with A-2 and G-1 designs all intended for sale to civilians - all of whom also had to have one. The original B-3 was a relatively heavy jacket, made from hand-dyed leather, giving it a lovely russet-brown color and a slightly mottled finish. These jackets had a shearling (or sheepskin) lining that extended below the cuffs and below the waist, which is where they get their name. It was ideal for high altitude flying missions where it was extremely cold for bomber pilots. Like all the other bomber jackets, this new design had a zippered front, but only one outside pocket, on the right hand side.
In 1942, the design of the B-3 was changed slightly, probably to save manufacturing costs. Instead of sleeves being cut from one piece of skin, strips of leftover russet-hued hand-dyed leather from the last 1941 production were used and stitched to darker brown leather on the topside of the arm. This was the same leather used for the body of the jacket.
The B-3 was replaced by the AN-J-4 in 1943, before the end of World War II. This design was also lined with sheepskin but the lining didn't show at the cuffs, and there was a single strap that closed the neck, instead of two. This shearling bomber jacket also had a zippered waist adjustment, and it had two pockets on the inside.
Today both the vintage style shearling bomber jacket and the contemporary lookalike mens bomber jacket are still popular because they look good and are extremely warm.
Article Source: [http://EzineArticles.com/?Why-Everyone-is-Looking-For-a-Shearling-Bomber-Jacket&id=4549353] Why Everyone is Looking For a Shearling Bomber Jacket
