page_title: Pan Am Flight 214
section_title: Investigation
hierarchical_section_title: Pan Am Flight 214 / Investigation
caption_attribution_description: 1963 Wire Photo worker looks at recorder Pan American Flight 214 Aircraft crash
context_page_description: Pan Am Flight 214 was a scheduled flight of Pan American World Airways from San Juan, Puerto Rico, to Baltimore, Maryland, and Philadelphia, Pennsylvania. On December 8, 1963, the Boeing 707 serving the flight crashed near Elkton, Maryland, while flying from Baltimore to Philadelphia, after being hit by lightning. All 81 occupants of the plane were killed. It was the first fatal accident on a Pan Am jet aircraft since the company had taken its first delivery of the type five years earlier.
  An investigation by the Civil Aeronautics Board concluded that the cause of the crash was a lightning strike that had ignited fuel vapors in one of the aircraft's fuel tanks, causing an explosion that destroyed one of the wings. The exact way that the lightning had ignited the fumes was never determined. However, the investigation revealed various ways that lightning can damage aircraft in flight, which led to new safety regulations. The crash also led to research into the safety of different types of aviation fuel and research into methods of reducing dangerous fuel-tank vapors.
context_section_description: The Civil Aeronautics Board (CAB) assigned more than a dozen investigators within an hour of the crash.  They were assisted by investigators from the Boeing Company, Pan American World Airways, the Air Line Pilots Association, Pratt & Whitney, the Federal Bureau of Investigation, and the Federal Aviation Agency.   The costs of investigations by the CAB at the time rarely exceeded $10,000, but the agency would spend about $125,000 investigating this crash (equivalent to $1,040,000 in 2019), in addition to the money spent by Boeing, the Federal Aviation Administration (FAA), the engine manufacturer, and other aircraft parts suppliers on additional investigations.
  Initial theories of the cause of the crash focused on the possibility that the plane had experienced severe turbulence in flight that had caused a fuel tank or fuel line to rupture, leading to an in-flight fire from leaking fuel.   U.S. House Representative Samuel S. Stratton of Schenectady, New York, sent a telegram to the Federal Aviation Administration urging them to restrict jet operations in turbulent weather, but the FAA responded that it saw no pattern that suggested the need for such restrictions, and the Boeing Company concurred.   Other possibilities of the cause of the crash included sabotage or that the aircraft had been hit by lightning, but by nightfall after the first day, investigators had not found evidence of either.  There was also some speculation that metal fatigue as a result of the aircraft's 1959 incident could be involved in the crash, but the aircraft had gone through four separate maintenance overhauls since the accident without any issues being detected.
  Investigators rapidly located the flight data recorder, but it was badly damaged in the crash.  Built to withstand an impact 100 times as strong as the force of gravity, it had been subjected to a force of 200 times the force of gravity, and its tape appeared to be hopelessly damaged.  Alan S. Boyd, chairman of the CAB, told reporters shortly after the accident, "It was so compacted there is no way to tell at this time whether we can derive any useful information from it."  Eventually, investigators were able to extract data from 95 percent of the tape that had been in the recorder.
  The recovery of the wreckage took place over a period of 12 days, and 16 truckloads of the debris was taken to Bolling Air Force Base in Washington, D.C., for investigators to examine and reassemble.  Investigators revealed that there was evidence of a fire that occurred in flight, and one commented that it was nearly certain that there had been an explosion of some kind before it crashed.  Eyewitness testimony later confirmed that the plane had been burning on its way down to the crash site.
  Within days, investigators reported that it was apparent that the crash had been caused by an explosion that had blown off one of the wing tips of the airplane.   The wing tip had been found about three miles (5 km)  from the crash site bearing burn marks and bulging from an apparent internal explosive force.  Remnants of nine feet (3 m) of the wing tip had been found at various points along the flight path short of the impact crater.  Investigators revealed that it was unlikely that rough turbulence had caused the crash because the crews of other aircraft that had been circling in the area reported that the air was relatively smooth at the time.  They also said that the plane would have had to dive a considerable distance before aerodynamic forces would have caused it to break up and explode, but it was apparent that the aircraft had caught fire near its cruising altitude of 5,000 feet.
  Before this flight, there had been no other known case of lightning causing a plane to crash despite many instances of planes being struck.   Investigators found that on average, each airplane is struck by lightning once or twice a year.  Scientists and airline industry representatives vigorously disputed the theory that lightning could have caused the aircraft to explode, calling it improbable.   The closest example of such an instance
caption: A CAB engineer examines the badly damaged flight recorder of Pan Am Flight 214
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