Bomber Jacket was first popular in
1950s
With the advent of air combat in World War II, pilots needed outerwear that was going to be functional in high-altitude cold weather, while still being streamlined enough to stay out of the way of plane operation. As flight tech advanced, cockpits became more cramped with tech, and planes could fly faster and higher. It's these details that spurred innovation from leather and fur, to wool and waterproofed nylon.
Today's bomber, depending on where you buy it, will either be a very close reproduction of the classic, or tailored towards modern tastes.
Source:http://www.complex.com/style/2015/03/a-history-of-the-bomber-jacket/bomber-jacket-beginnings