DC-3 Flight NC-16002, 1948
On December 28, 1948, a DC-3 passenger plane, considered to be one of the most reliable aircraft ever built, was flying on a route from San Juan, Puerto Rico to Miami. The weather was good, and when the plane was 50 miles (80 kilometers) from Miami, the aircraft's pilot, Captain Robert E. Linquist, contacted an air traffic control center in New Orleans to give his coordinates. This was strange as he should have been radioing Miami. That communication was the last that anyone heard from the aircraft, which had three crew members and 29 passengers aboard. When the plane didn't arrive in Miami, the U.S. Coast Guard began a search, and was joined by the U.S. Navy, the Air Force, and other searchers. A Civil Aeronautics Board investigation later found that the aircraft's batteries were not properly charged, and that it was possible that an electrical system failure rendered the aircraft's radio and automatic compass inoperative. (The pilot could transmit messages but not receive them.) It's likely that Linquist was mistaken about his location. In addition, he might not have known about an unexpected change in the wind, which could have taken the plane off course. With only an hour and 20 minutes' worth of fuel left, "an error in location would be critical," the board's report noted [source: CAB].
The S.S. Marine Sulphur Queen, 1963
On Feb. 2, 1963, the S.S. Marine Sulphur Queen, a 19-year-old, 7,200-ton (6,532 metric tons) oil tanker was bound for Norfolk, Virginia from Beaumont, Texas carrying 15,000 tons of molten sulfur in heated tanks. But it never reached its destination. Unlike some of the other vanished craft in the Bermuda Triangle, though the ship was never found, debris was recovered, including pieces of a raft, a life vest, and a broken oar. The ship was in poor repair and had suffered reoccurring fires around its sulfur tanks. (Once it put out to sea while still burning.) The cooled sulfur emissions from those blazes had hardened and caked the ship's pumps, corroded electrical equipment, and even shorted out the ship's generator. Time magazine noted that the mystery was not that the ship had disappeared, but "how it had managed to put to sea in the first place."
Milwaukee's 440th Airlift Wing, Plane 680, 1965
On a clear night in 1965, a seasoned flying crew from the Air Force Reserve Command's 440th Airlift Wing flew from Milwaukee in a C-119 Flying Boxcar on their way to Grand Turk in the Turks and Caicos Islands, south of the Bahamas. They landed as scheduled at Homestead Air Force Base in Florida at 5:04 p.m. and spent two hours and 43 minutes on the ground. Then they took off at 7:47 p.m. and headed toward Grand Turk, but never reached their destination. There was no indication of trouble and all radio communication was routine. When they didn't land, radio traffic controllers started calling Plane 680 but didn't receive a response. Only a few scraps of debris were found, and those could have been tossed out of the cargo plane. Among those on board was an expert maintenance crew, so if there was a mechanical problem on the flight, there were plenty of people to take care of it. The investigation report at the time surmised, once again, that the plane had run out of fuel [source: Jones].