During the pre-flight inspection the pilot noticed that the left aileron was buckled. Further inspection revealed diagonal wrinking of the lower surface of the left wing, the leading edge of the left wing outboard of the engine nacelle, and evidence of movement in the left wing attachment area. The pilot stated that when he flew the aircraft on the previous day it had handled normally. The weather conditions on that day were such that at cruise the flight was smooth with light turbulence during the descent. An analysis of the damaged aileron concluded that it had failed in static overload. An engineering assessment of the damaged to the aircraft concluded that the most likely scenario to cause the damage was one involving high speeds and gusts. These conditions were not reported by the pilot.