What happened
On a scheduled cargo flight from New York-JFK to Frankfurt, with a stop in Scotland, the Boeing 707 operated by Pan American World Airways encountered significant issues shortly after departure. While cruising near Montreal, Canada, the crew reported that smoke had begun accumulating in an electrical compartment. The flight was initially diverted toward New York but was subsequently redirected to Boston as the density of the smoke increased, making the cockpit environment increasingly difficult for the crew to manage.
As the aircraft approached Boston, the crew requested runway 33L and expressed a desire to land as quickly as possible. During the descent, several systems became unreliable; the crew noted that distance measuring equipment was non-functional and later, their transponder ceased operation. The captain ordered the shutdown of non-essential systems to manage the situation. While attempting the final approach with flaps and spoilers extended for speed reduction, the aircraft became difficult to handle. The plane ultimately struck the ground nose-down approximately 262 feet from the edge of the runway, resulting in 3 fatalities and the total destruction of the aircraft.
Findings
Investigators determined that continuous smoke generation within the cockpit created an uncontrollable emergency situation. This dense smoke severely hindered the crew's vision and their ability to perform necessary tasks effectively. A critical factor in the loss of control was the uncoordinated execution of emergency procedures, which resulted in the deactivation of the yaw damper while the aircraft was in a configuration that made low-speed handling extremely difficult.
While the exact origin of the smoke remained unconfirmed, it was believed that a spontaneous chemical reaction occurred between leaking acid and its sawdust packaging. This reaction was linked to the improper stowage and packaging of hazardous materials. Furthermore, a lack of adherence to regulations regarding the transport of dangerous goods contributed to the accident sequence.