Keystone B-6A Published on December 26, 2012 in 27 December 1935Full resolution (1800 × 1154) ← Previous Next → Three Keystone B6As of 20th Bombardment Squadron, 2d Bomb Group, release their bombs on a practice mission. (U.S. Air Force)A Keystone B-6A of the 20th Bomb Squadron, 2nd Bomb Group, Langley Field, Va., dropping bombs. (U.S. Air Force photo)