The exact manner of ignition was never determined, but the investigation increased awareness of how lightning can damage aircraft, leading to new regulations that resulted in safety improvements.

[1]: 2  Flight 214 left San Juan at 4:10 pm Eastern Time on December 8, 1963, with 140 passengers and eight crew members.

The controller asked whether the pilots wanted to proceed directly to the airport or to enter a holding pattern to wait for the storm to pass.

[1]: 3  Heavy rain was falling in the holding area, with frequent lightning and gusts of wind of up to 50 miles per hour (43 kn; 80 km/h).

Seconds later, the first officer of National Airlines Flight 16, flying 1,000 feet (300 m) higher in the same pattern, radioed, "Clipper 214 is going down in flames.

The engines were buried in the ground 10 to 15 feet (3 to 5 m) from the force of the impact.Firefighters and police officers soon recognized that a rescue operation was pointless and all they could do was extinguish the fires and begin collecting bodies.

[7] First responders and police from across the county, along with men from the United States Naval Training Center Bainbridge, assisted with the response.

[8] They positioned flares around the area to define the accident scene and set up searchlights to illuminate it to ensure that the debris and human remains were undisturbed by curious spectators.

[10] The state medical examiner needed nine days to complete the identification of the victims, using fingerprints, dental records, and personal effects that had been found nearby.

[1]: 5  Portions of the plane's right wing and fuselage, right main landing gear, horizontal and vertical tail surfaces, and two of the engines were found within 360 feet (110 m) of the crater.

[4][2] The Civil Aeronautics Board (CAB) was notified of the accident and investigators were dispatched from Washington, D.C.[1]: 14 [4] Witnesses of the crash described hearing the explosion and seeing the plane in flames as it descended.

[1]: 1  Named the Clipper Tradewind,[12] it was the oldest commercial jet airliner in the United States at the time of the crash.

The plane was reported to have entered a sudden spin during a demonstration of the aircraft's minimum control speed, during which the engine broke away.

[1]: 8 The recovery of the wreckage took 12 days, and 16 truckloads of debris were taken to Bolling Air Force Base in Washington, D.C., for investigators to examine and reassemble.

The left wing tip had been found a few miles from the crash site with burn marks and bulging from what looked like an internal explosion.

Remnants of 9 feet (3 m) of the wing tip had been found at several points along the flight path short of the impact crater.

Investigators said rough turbulence was unlikely to have 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 the plane would have had to dive a considerable distance before it would break up and explode, but the aircraft had apparently caught fire close to its cruising altitude of 5,000 feet (1,500 m).

[22] Experts and airline industry representatives disputed the early theory that lightning could have caused the aircraft to explode, calling it improbable.

[18]: 34  The CAB launched an urgent research program in an attempt to identify conditions in which fuel vapor in the wing tanks could have been ignited by lightning.

[21] Within a week of the crash, the FAA issued an order requiring the installation of static electricity dischargers on the approximately 100 Boeing jet airliners that had not already been so equipped.

[27] The investigators concluded that a lightning strike had ignited the fuel-air mixture in the number-one reserve fuel tank, which had caused an explosive disintegration of the outer part of the left wing, leading to a loss of control.

The board said, "It is felt that the current state of the art does not permit an extension of test results to unqualified conclusions of all aspects of natural lightning effects.

[22] The committee agreed to conduct both long-range and short-range studies of the impact of lightning on aircraft fuel systems and potential measures to defeat such hazards.