Investigation Summary
The flight was a short 30-minute hop from Singapore. Upon arrival at Kuala Lumpur, the crew faced several operational challenges, including the unavailability of the ILS for Runway 33, necessitating a less precise NDB approach. Communication was further complicated by the use of the identifier 'KL' for multiple navigation aids and the airport itself, leading to confusion in the cockpit regarding radio tuning. The First Officer, who was the pilot flying, expressed significant discomfort with the approach, noting he did not have the approach plate in front of him and questioning how they would find the runway. Despite these concerns, the Captain, acting as the pilot monitoring, remained casual and did not switch to a more precise approach available on the reciprocal runway. The critical failure occurred when the controller issued a descent clearance using non-standard phraseology. The Captain's readback of 'four zero zero' was not corrected by the controller, and the crew subsequently ignored multiple Ground Proximity Warning System (GPWS) alerts as they descended into the hillside.
Final Conclusions
The Malaysian Department of Civil Aviation (DCA) concluded the accident was a Controlled Flight Into Terrain (CFIT) caused by a combination of crew error and air traffic control deficiencies. The primary cause was the misinterpretation of the altitude clearance, exacerbated by the use of non-ICAO standard phraseology by both the controller and the captain. Contributing factors included poor Crew Resource Management (CRM), the crew's failure to adhere to instrument approach procedures, and the total disregard for GPWS warnings during the final descent.
Video Analysis
How Did This 747 Crew Descend Into a Mountain? | Flying Tiger 66 — A detailed reconstruction of the communication breakdown and CRM failures that led to the crash of Flying Tiger Line Flight 66 in Malaysia.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Systems & Failure Modes
GPWS
The Ground Proximity Warning System provided multiple 'Pull Up' alerts prior to impact, but the crew failed to take corrective action, likely believing they were on a safe glide path.
NDB Approach
A non-precision approach using a Non-Directional Beacon. This procedure requires higher pilot workload and provides only lateral guidance, not vertical.
Interesting Facts
- 01The aircraft was a Boeing 747-200 freighter named 'Thomas Haywood'.
- 02The Captain interpreted 'two four zero zero' as 'to four zero zero', leading to a 2,000-foot altitude error.
- 03The First Officer was the pilot flying but did not have an approach plate for the NDB procedure in front of him.
- 04The aircraft struck treetops at 600 feet MSL and came to rest on a hillside at 481 feet MSL.
- 05The aircraft was owned by FedEx at the time of the accident but was still being operated under the Flying Tiger Line brand.
Safety Actions & Advisories
Standardization of Phraseology
ICAO emphasized the mandatory use of standard phraseology, specifically requiring the word 'thousand' in altitude clearances (e.g., 'two thousand four hundred' instead of 'two four zero zero') to prevent phonetic confusion.
CRM Training Enhancement
Airlines intensified Crew Resource Management training to encourage First Officers to be more assertive when they perceive a safety risk or ambiguity in Captain's decisions.