What happened
On August 26, 2018, a HAIC Y12E aircraft, registration HK5036, operated by SATENA, was performing a scheduled passenger flight from Araracuara (SKAC) to Florencia (SKFL). While cruising at 10,500 feet, the crew identified two convective weather cells (yellow and red echoes) on the onboard radar approximately 10 to 15 nautical miles ahead. The crew decided to maneuver the aircraft to fly between these two formations.
At 15:23 local time, the aircraft encountered severe turbulence. The encounter triggered a rapid descent of approximately 5,000 feet in just 22 seconds, with a vertical descent rate reaching 12,231 feet per minute. During this period, the aircraft experienced extreme aerodynamic stresses, including stall warnings and overspeed indications. The airspeed reached 248 knots, significantly exceeding the manufacturer's maximum operating speed (VNE) of 177 knots. The crew eventually regained level flight at approximately 6,000 feet. Although the aircraft landed safely in Florencia, the intense G-forces caused structural deformations and significant damage to the airframe.
One passenger sustained minor injuries due to not having their seatbelt properly fastened during the turbulence.
The investigation
The GRIAA investigation focused on the flight path, meteorological conditions, and the crew's decision-making process. Investigators analyzed the cockpit voice recorder (CVR) and flight data recorder (FDR) to reconstruct the sequence of events. The investigation examined the radar imagery, which showed active convective clouds, and evaluated the structural integrity of the aircraft following the encounter. The investigation also reviewed the crew's adherence to standard operating procedures and their response to the identified weather hazards.