What happened
Following a standard radio check on the ground, Flight 629 taxied to runway 08R. At 18:44, the crew received air traffic control clearance for a flight to Portland, which included instructions to provide specific radio reports when passing the Denver Omni and upon reaching an altitude of 21,000 feet. The aircraft departed the airport, with the crew recording an off-time of 18:52. At 18:56, the flight successfully reported passing the Denver Omni; however, no further communications were received from the aircraft.
At approximately 19:03, air traffic controllers at the Denver tower observed two distinct white lights descending toward the ground in a north-northwest direction relative to the airport. These lights appeared to fall at a similar velocity and remained visible for roughly 30 to 45 seconds. This was followed by a bright flash near the ground that illuminated the cloud base at an altitude of about 10,000 feet. Controllers immediately began checking the status of all aircraft in the vicinity to identify any planes in distress. While all other nearby aircraft were accounted for, it was determined that Flight 629 had crashed. The accident resulted in 44 fatalities.
Findings
Investigations concluded that the dynamite bomb explosion occurred within the number 4 baggage compartment of the aircraft. Physical evidence at the crash site and subsequent laboratory analysis confirmed that the destruction was caused by an explosive device rather than any mechanical or system failure. The aircraft was climbing normally and following its assigned course at the moment the disintegration occurred. It was later determined that an explosive device had been placed on board by a passenger.