What happened
On October 28, 1953, British Commonwealth Pacific Airlines Flight 304/44 departed Honolulu, Hawaii, bound for San Francisco, California. The aircraft, a Douglas DC-6 registered as VHBPE, was carrying 10 adults and one child. After an initial departure from Honolulu, the crew briefly requested to return to the airport due to issues with a propeller, but they subsequently resumed their flight plan toward the United States mainland.
As the aircraft approached the California coast, the crew transitioned from radio code to voice communications. At 0807, San Francisco Air Route Traffic Control cleared the flight for a descent under Visual Flight Rules, instructing them to maintain at least 500 feet above the cloud tops. The flight was cleared for an ILS approach to Runway 28 at San Francisco. The last successful communication from the crew occurred at approximately 0842, when they reported being southeast and turning inbound toward the outer marker.
Following a period of silence where all subsequent radio calls went unanswered, search and rescue teams were mobilized. The wreckage was discovered at 1010 near Half Moon Bay, located roughly seven and one-half miles southeast of the town. The impact occurred in a mountainous region at an elevation of 1,950 feet. There were 19 fatalities and no survivors.
Findings
Investigations into the crash determined that the primary cause was the crew's failure to adhere to established procedures for conducting an instrument approach. Several contributing factors were noted:
- The air traffic control clearances provided to the aircraft were accurate and properly acknowledged by the crew.
- All navigational aids and landing facilities at the destination were operational and functioning as intended.
- Local weather conditions involved a ceiling of 1,200 feet, which prevented the pilots from using visual ground references for navigation.
- The flight's timing made it impossible to complete the transition from the Half Moon Bay Fan Marker to the ILS outer marker and still execute the approved instrument approach procedure.
- No evidence of mechanical or structural malfunction was found within the wreckage prior to the collision with the terrain.