World War II is a unique time in world history that no matter how much time passes, the stories that come from it remain as captivating as ever. From political decisions to military strategy, almost all of the big issues have been studied and discussed ad nauseam, but fascinating details can often be rediscovered.
This educational video, for instance, explains how machine gun defenses worked on Boeing B-17 airplanes and how their flying crews were trained. The B-17 design went through eight major changes over the course of its production, culminating in the B-17G, differing from its immediate predecessor by the addition of a bombardier-operated, remotely controlled chin turret with two .50 caliber M2 Browning machine guns under the nose. Before the advent of long-range fighter escorts, B-17s had only their .50 caliber M2 Browning machine guns to rely on for defense while flying over.
For anyone interested in war history and learning how things work, this video is a must see: