DC-3 Flight NC-16002, 1948

On December 28, 1948, Captain Robert Lindquist of flight NC-16002 was piloting DC-3 commercial flight NC-16002 from San Juan, Puerto Rico to Miami, Florida. He radioed Miami when they were 50 miles away and requested landing instructions. Miami radioed back with the instructions, but got no reply. The plane never arrived and was never heard from again. Although many reports state there was no radio trouble and that the weather was clear, the accident investigation report from the Civil Aeronautics Board says differently.
According to the report, the plane had electrical difficulties from the beginning and its batteries needed a recharge so it could communicate with the tower. But rather than charging the batteries prior to takeoff, Lindquist instructed the ground crew to refill the water in the batteries and replace them in the plane. He originally canceled his flight plan because of the battery difficulties, and was directed to remain in San Juan until he established radio contact with the tower and reinstated his flight plan. But 11 minutes after takeoff, Lindquist radioed to the tower that they were proceeding to Miami. The tower never received the transmission, but CAA Communications in San Juan did. All attempts to contact the flight were unsuccessful. In the flight's final radio communication, Lindquist stated that they were 50 miles south of Miami.
The Civil Aeronautics Board report analysis includes the assumption that some failure in the electrical system made the aircraft's radio and automatic compass inoperative after the final communication. It also assumes that because Captain Lindquist didn't communicate with the tower, he didn't know about changes in the weather. The wind direction had changed, which would have made his plane drift left of its actual course by as much as 50 miles. Since the captain's location was an estimate based on his flight time, speed, and weather conditions, he could easily have been off-course. The plane had fuel for seven and a half hours of flight. At the time of his last communication, he had been flying for a little more than six hours. He may have then crashed into the Gulf of Mexico after running out of fuel. No debris was found, but the crash could have occurred in an area where the water is extremely deep and any evidence of the crash would disappear quickly.