Damage Discovery
After landing in Memphis, inspectors found wrinkling damage on the outboard elevators and their counter weights. The damage was observed during a routine post-flight inspection.
Crew and Data Reports
The flight crew stated that they did not experience any turbulence or unusual events during the flight that could have caused the damage. Analysis of the digital flight data recorder (DFDR), which contained 25 hours of data, did not reveal any events that would have led to the observed damage.
Inspection Findings
A detailed examination of the elevators showed no material defects or preexisting damage. The aircraft had undergone an 'A' check on the ground before departing for Memphis, and during that check, no discrepancies were noted with the elevators. Additionally, the flight engineer reported that no issues with the elevators were observed during the preflight inspection prior to the flight to Memphis.
Manufacturer's Statement
The aircraft manufacturer indicated that similar elevator damage has been observed in other cases, attributed to stall buffet at high altitude or high speed buffet at high altitude. However, no specific cause for this particular instance was determined.