What happened
Upon arrival at Memphis, an inspection of the aircraft revealed wrinkling damage located on the outboard elevators and the elevator counterweights. The flightcrew reported that the flight was completed without encountering any turbulence or other specific atmospheric events that could have caused such structural deformation.
During the preflight inspection for the flight to Memphis, the flight engineer reported that no discrepancies regarding the elevators were observed. Additionally, the aircraft had recently undergone an 'A' check while on the ground prior to its departure, during which no issues with the elevator components were noted.
The investigation
Investigators performed a readout of the 25 hours of data stored on the digital flight data recorder (DFDR). This analysis did not reveal any flight events or conditions that would account for the damage. A physical examination of the elevators was conducted, which showed no evidence of material defects or preexisting damage.
During the investigation, the aircraft manufacturer provided information regarding similar occurrences, stating they have previously observed comparable damage to elevators resulting from stall buffet at high altitude or high-speed buffet at high altitude.