China Airlines Flight 642

Investigation

The final report of the accident blamed it mainly on pilot error, specifically the inability to arrest the high rate of descent existing at 50 ft altitude on the radar altimeter. The descent rate at touch down was 18–20 ft/s.

The flight data stored in the volatile memory of the aircraft's Quick Access Recorder (QAR) during the last 500 ft of the approach could not be recovered due to the interruption of the power supply at impact. Probable wind variations and the loss of headwind component, together with the early retardation of thrust levers, led to a 20 knots loss in indicated airspeed just prior to touchdown.

Due to the severe weather conditions forecast for Hong Kong, the flight crew had prepared to divert the flight to Taipei if the situation at Hong Kong was deemed unsuitable for landing. Extra fuel was carried for this possibility, resulting in a landing weight of 429557 lb, 99.897% of its maximum landing weight of 430,000 lb. Based on the initial weather and wind check which was passed along to the crew from Hong Kong during the flight, they believed they could land there and decided against a diversion to Taipei. However, four earlier flights had carried out missed approaches at Hong Kong and five had diverted.

During the final approach, the plane descended along the Instrument Landing System (ILS) glideslope until the crew visually acquired the runway at about 700 ft. They disengaged the autopilot but left the autothrottle on. During the flare, the rate of descent was not arrested, the plane landed with the right wing slightly lower. The right landing gear touched down first, the right engine impacted the runway and the right wing was detached from the fuselage. Since the left wing was still attached, the lift from that wing rolled the fuselage onto its right side, and the plane came to rest inverted in the grass strip next to the runway. The spilled fuel caught fire.

Several suggestions were given to China Airlines concerning its training. However, China Airlines disputed the report's findings on the flight crews' actions, citing the weather conditions at the time of the accident and claimed that the aircraft flew into a microburst just before landing, causing it to crash.