B-29 Enola Gay empennage

The famous film of the mushroom cloud rising over Hiroshima was shot by the tail gunner from this position.

Colonel Tibbets, the commander of the nuke squadron, stripped most of the guns from the B-29s in his unit to save weight in order to carry the very heavy atom bombs. The Japanese fighters figured this out pretty fast during the unit's practice runs over Japan and began looking for B-29s with the nuke squadron's letter on the tail. It was like hanging a big "Kick Me" sign on them. They switched to the R of the conventional B-29 wing which was hosting them to blend in better.