How about some shiny aluminum for Tuesday?
This is the YB-17, the pre-production prototype of the B-17 Flying Fortress. What might be considered a prototype, the Model 299, had crashed during its competition with the twin-engine Douglas B-18 Bolo. The pilots forgot to remove the gust locks from the control surfaces prior to takeoff. Despite losing the competition to Douglas, the Model 299 so impressed the Army that they ordered 13 more so they could continue to test them. The B-17 was finally introduced in 1938, and it went on to become the third most-produced bomber in history (12,731), while the Bolo is practically forgotten. However, the B-17s that filled the skies of Europe and, to a lesser extend, the Pacific, underwent significant structural changes from the YB-17. The most obvious was the extension of a dorsal ridge in front of the vertical stabilizer to prevent rudder lock, and the addition of a tail gunner position. The definitive G model added a chin turret to dissuade enemy fighters from attacking head on.