The Type E-1 trousers, part of the U.S. Air Force issue since 1949, are a cold-weather inner wear system designed to be worn with the A-1 shirt. Made from a premium wool serge, these trousers are developed for use underneath intermediate flight suits such as the B-15B/A-11B, heavy zone flight suits like the N-2/D-1, and N-3/F-1. The knees and hips feature protective cushioning with a wool pile, covered in a smooth nylon for added comfort.Additional features include ribbed hems to prevent cold air intrusion. Originally designed to be worn with suspenders and a back cinch, this updated version removes the back cinch and adds belt loops for modern utility. Similar to the variations seen in the L-2 and N-2 series, the trousers have undergone color regulations with changes from E-1 to E-1A to E-1B.
