What happened
On January 30, 1974, Pan Am Flight 806, a Boeing 707-321B operating as 'Clipper Radiant', was conducting a scheduled service from Auckland, New Zealand, with planned stops in American Samoa and Hawaii. While approaching Pago Pago, the aircraft was cleared for an ILS DME runway five approach. During the descent, the crew communicated with Approach Control regarding weather conditions, noting heavy rain and visibility restrictions.
As the flight descended through 5,500 feet and intercepted the localizer, the crew noted that runway lights remained visible despite the weather. However, at approximately 23:40, the aircraft's radio altimeter warning tone sounded. The first officer noted the aircraft was high and then reached minimums, reporting the field in sight at 140 knots. Shortly thereafter, the aircraft struck trees at an elevation of 113 feet, roughly 3,865 feet before the runway threshold. The wreckage continued through jungle vegetation and hit a lava rock wall, coming to rest approximately 3,090 feet from the threshold.
The accident resulted in 12 fatalities (including passengers and crew who succumbed to injuries later) and only 9 survivors of the initial impact. Of the total 101 occupants, several passengers and one crew member survived the crash and fire, but others died in the days following the event.
Findings
Investigation into the accident identified that the flight crew failed to timely recognize and correct an excessive descent rate. This rapid descent was triggered by destabilizing wind changes, which included both horizontal and vertical components caused by a heavy rainstorm and the surrounding uneven terrain. The captain's ability to identify the deviation was further compromised by poor visibility, the visual illusions of a "black hole" approach, insufficient monitoring of flight instruments, and a failure by the crew to communicate the descent rate during the final 15 seconds of the flight.