With the arrival of the newer B-17G and B-24's by mid war most B-17Es were either converted into unarmed transports or scrapped. Old 666 was returned to the United States in February 1944 and was salvaged at Albuquerque in August 1945.
Here's the history (according to wiki):
By 1943 Old 666, tail number 12666, had suffered heavy battle damage and had gained a reputation as a cursed bomber, often coming back from missions with heavy damage. Grounded at Port Moresby Airport, it was parked at the end of the runway where other aircrews could cannibalize it for needed parts. A friend of Zeamer's said to him, "I know where there’s a bomber, but no one will fly it anymore because every time it goes out it gets shot to hell!"
Captain Zeamer, who had been unable to acquire an aircraft of his own, had the bomber towed out of the 'bone yard' and, with enormous effort, not only restored the badly battered aircraft to flight status but made many changes.
They included increasing the number of machine guns from 13 to 19, replacing the waist gunners' standard single guns with twin guns, replacing all .30 cal machine guns with the larger and more powerful .50 cal, and adding a fixed-position gun that could be fired from the pilot's station. Zeamer's crew put guns where they didn't even need them, and left spare machine guns on the aircraft's catwalk; if a gun jammed at a critical moment they could dump it and quickly replace it. These modifications made Old 666 the most heavily armed bomber in the Pacific Theater.[1]
They also mounted a gun behind the ball turret near the waist. In the months of missions that followed, Zeamer's crew was so busy that they never had the time to adorn their bomber with the traditional nose-art, commonly seen on aircraft of that era.
Though many subsequent accounts refer to the bomber as "Lucy," that was not a title Zeamer and his crew ever used. The only markings the converted B-17E bore was the tail number—the bomber became known simply as Old 666. In May, Zeamer and crew made a skip-bombing run on a Japanese aircraft carrier, swooping within fifty feet of its decks.
A few days later on a daylight bombing raid over Rabaul, Old 666 came in so low it was brushing the roofs of the housetops. On a night mission over Wewak the Japanese gunners on the ground managed to fix the flight of incoming American bombers in the glare of several large searchlights, but, in an audacious display of airmanship, Zeamer dove on the positions, shooting out three and damaging two others.
On a May 5 mission over Madang, Old 666 was hit more than sixty times by anti-aircraft fire, the stabilizer was shot out and the oxygen tanks exploded, yet the aircraft landed safely and was quickly patched. (lol)
On June 16, 1943 a request went out for a special mission, a single ship unescorted mapping mission over hostile territory. Capt. Zeamer and crew eagerly volunteered.
Taking off at 4 A.M. to make use of darkness to cover at least part of the mission 'Old 666' and crew headed for Bougainville, where they were instructed to make a reconnaissance of the Japanese airfield there to determine logistics and enemy strength.
The flight would require flying over 600 miles of open sea to even reach the target. By 7:40 AM with only 22 minutes of flight-time remaining to complete its mission, Old 666 was intercepted by no less than 17 Japanese fighters (15 A6M Zeros & 2 Ki-46 Dinahs) of the 251st Kokutai Squadron, commanded by Chief Flight Petty Officer Yoshio Ooki.[2]
After making a pass at the heavily armed tail the fighters came in against the normally lightly armed nose only to find that this specific bomber possessed much heavier forward firepower, resulting in two A6M Zeros being shot down. However, 20mm cannon shells from a third Zero smashed into the cockpit and nose wounding both Zeamer and Sarnoski before being shot down itself. Sarnoski crawled out of the nose to seek first aid attention but when a Ki-46 Dinah attacked nose on he returned to his guns, shot it down and then shortly thereafter collapsed.[1]
The second wave knocked out the oxygen system and forced the bomber to dive from 25,000 ft to 8,000 ft, where the crew could breathe normally, in just a matter of seconds.
By 8:45 AM the American bomber was over open seas and the enemy fighters, low on ammunition and fuel, were forced to turn back to Bougainville, most of the crew had been wounded in varying degrees and the aircraft was shot full of holes. It was during the return flight that Zeamer lost consciousness and Sarnoski, still manning his guns, died.
Upon landing the co-pilot told the ground crews, "Get the pilot last. He's dead!" He was not, and Zeamer lived to receive the Medal of Honor, but Sarnoski's Medal of Honor was awarded posthumously. In one of the most decorated flights in history, the rest of the entire crew received Distinguished Service Crosses.[3] This mission was featured on the episode "Long Odds" on the History Channel show Dogfights.
