Occurrence
On 10 June 2017 at 13:00 LMT, a Cessna 172S, registration SP-MMC, operated by IBEX-U.L. sp. z o.o., was on a recreational flight with three passengers in the vicinity of Warszawa-Babice airport (EPBC). After completing the flight, the pilot performed a landing on the grass runway 28. During the flare, the aircraft banked to the left due to an unexpected asymmetric thermal gust, resulting in a hard touchdown on the left main landing gear. The aerodynamic configuration and available engine power did not allow avoidance of the event.
After stopping, the pilot taxied off the grass runway and proceeded toward the IBEX hangars. Approximately 25 meters from the concrete apron in front of the hangar, the left main landing gear leg fractured near its attachment to the fuselage.
Damage
The aircraft tipped onto the left wingtip and left horizontal stabilizer, causing bending and fracture of the left stabilizer and left elevator segment. The left main landing gear leg was broken. No occupants sustained any injuries.
Investigation
The event was initially classified as an incident and investigated by the aircraft operator. After the operator submitted a report, the Polish State Commission on Aircraft Accident Investigation (PKBWL) reclassified it as an accident due to the extent of damage.
Cause
The cause of the accident was a hard landing resulting from an unexpected asymmetric thermal gust during the flare phase of landing. Contributing factors included local weather conditions.
Safety Actions
No preventive actions were taken by the operator. The Commission issued no safety recommendations.