Occurrence
On 30 December 2020, a Bombardier BD-700-1A10 (Global 6000), registration 9H-OJP, operated by Elit’Avia Malta Limited as flight EAU52P, was conducting an instrument flight rules positioning flight from Incheon International Airport, Republic of Korea, to Taichung International Airport, Taiwan. The aircraft carried two pilots and one cabin crew member.
Weather Conditions
At the time of landing, Taichung International Airport was affected by a strong cold high-pressure weather system. Meteorological reports indicated good visibility but strong gusty winds with a significant crosswind component for runway 36.
Flight Crew Actions
Approximately two seconds before touchdown, the flight crew made significant and rapid control wheel inputs to counteract roll and pitch disturbances caused by gusty winds. The autopilot had been disengaged at 219 feet radio altitude, leaving the pilot flying only 16 seconds to transition from automatic to manual flight before initiating the flare at 30 feet. The pilot flying applied a right wing down control input, resulting in a maximum roll angle of 6.76 degrees right wing down and a pitch attitude of 9.31 degrees nose up at zero feet radio altitude. This caused a hard touchdown on the right main landing gear with a right rolling motion, and the right wing tip likely contacted the runway.
After the right main gear touched down and bounced, the pilot flying applied a left wing down input to stop the roll. The aircraft then rolled left, reaching a maximum left wing down roll angle of 9.4 degrees at a pitch attitude of 8.26 degrees. The left wing tip subsequently contacted the runway surface.
Damage
The left wing slat and aileron, as well as the right winglet, aileron, and flap canoes, were damaged. No injuries to the persons on board were reported.
Investigation Findings
The Taiwan Transportation Safety Board (TTSB) investigated, with participation from the Maltese Bureau of Air Accident Investigation, the Transportation Safety Board of Canada, Bombardier, and Elit’Avia Malta Limited. The investigation identified findings related to probable cause, risk, and other aspects.
Findings related to probable cause included the strong and gusty wind conditions, insufficient time to gain complete control of the aircraft due to late autopilot disconnection, rapid decrease in airspeed from headwind reduction not compensated by increased thrust, increased pitch angle from the pilot flying's pitch-up control demand, and significant rapid control inputs during flare to compensate for roll and pitch disturbances.
Risk-related findings noted that the autopilot was disengaged at 219 feet, giving the pilot flying only 16 seconds to transition to manual flight before the flare, insufficient for strong gusty conditions. Additionally, differences in recommended Vref speed adders across manuals may create confusion and affect standardization.
Other findings confirmed the flight crew were properly certificated and qualified, with no evidence of medical issues, fatigue, or substance impairment. The aircraft was properly certified with no flight control issues, and weight and balance were within limits. The approach was stable according to company criteria.
Probable Cause
The TTSB determined that the combination of strong gusty wind conditions, insufficient time to gain complete control due to late autopilot disconnection, rapid headwind reduction not compensated by thrust increase, increased pitch angle by the pilot flying, and significant rapid control inputs during flare resulted in an abnormal runway contact where both wing tips struck the runway.