Aluminum Overcast

K-13 gunsight on a B-17 waist machine gun. Speed and altitude settings can be seen

I always imagined that the machine guns on WW2 bombers like the B-17 and the B-24 had iron sights, but no. Here we've got a complicated black box that figures out the amount of lead you need depending on your altitude and speed. This from an aircraft that was built in 1944 and never actually saw any combat, so it's possible this was a mid-war development. Bernard Zee took this and a bunch of other photos, including inflight and interior shots on the ground, when the Aluminum Overcast visited Hayward California back in 2011. Via Posthip Scott.