Investigation Summary
The investigation highlighted a breakdown in Crew Resource Management (CRM). The captain, who was suffering from fatigue after being reassigned from a Dubai flight, mistakenly believed the glideslope was operational despite being briefed otherwise. The first officer and flight engineer failed to effectively challenge the captain's decision to descend. Furthermore, the FAA had inhibited the Minimum Safe Altitude Warning (MSAW) system at Guam due to frequent false alarms, which prevented air traffic controllers from receiving a low-altitude alert that could have warned the crew of the impending impact.
Final Conclusions
The NTSB determined the probable cause was the captain's failure to adequately brief and execute the non-precision approach, and the flight crew's failure to monitor the approach. Contributing factors included the captain's fatigue, inadequate CRM training at Korean Air, and the FAA's intentional inhibition of the MSAW system at Guam.
Video Analysis
The Tragic Crash of Korean Air Flight 801 — A detailed look at the factors leading to the 1997 crash of a Boeing 747 in Guam, focusing on pilot fatigue and the disabled safety systems.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
GPWS
Ground Proximity Warning System; provided 'Sink Rate' and 'Pull Up' warnings 6 seconds before impact.
MSAW
Minimum Safe Altitude Warning; a ground-based safety tool that was inhibited by the FAA at Guam at the time of the accident.
ILS Glideslope
The vertical guidance component of the Instrument Landing System, which was known to be inoperative.
Interesting Facts
- 01The glideslope for Runway 06L was officially out of service for maintenance.
- 02The captain was originally scheduled for a flight to Dubai but was reassigned due to rest requirements.
- 0326 people survived the initial impact and post-crash fire.
- 04The Minimum Safe Altitude Warning (MSAW) system at Guam was inhibited and did not alert controllers.
- 05The aircraft struck Nimitz Hill approximately 3.3 nautical miles from the runway threshold.
Safety Actions & Advisories
MSAW Configuration
The FAA was mandated to review and correctly configure MSAW systems at all airports to prevent unnecessary inhibition.
Korean Air CRM Overhaul
Korean Air implemented significant changes to its pilot training and Crew Resource Management programs to address hierarchical communication issues.
Terrain Awareness Systems
Accelerated the adoption of Enhanced GPWS (EGPWS) which provides a forward-looking terrain display.