The airplane sustained substantial structural damage to the fuselage in the nose wheel area during landing. The same flight crew flew the airplane from Atlanta to El Salvador and back to Atlanta. Another flight crew boarded the airplane and continued on to Los Angeles. No discrepancies were reported by either of the flight crews or maintenance personnel in El Salvador and Atlanta. After the airplane arrived in Los Angeles, a post flight walk around inspection revealed that the outside of the fuselage buckled on the left side above the nose landing gear door. Further examination disclosed that structural members were bent and fractured in the nose wheel well. The crew that landed in El Salvador stated that the nose gear touched down more firmly than the main landing gear. They completed a post flight inspection, but detected no abnormalities. The flight data recorder was removed and sent to the Safety Board’s Vehicle Recorder Laboratory for readout and evaluation. A Safety Board specialist conducted a data comparison for the landings in El Salvador, Atlanta, and Los Angeles. In the El Salvador landing sequence, the air/ground FDR discrete indicated “air” then a second later indicated “ground.” A second later it indicate “air” again and then a second later indicated “ground” and remained “ground” for the remainder of the landing roll out. During this phase, a right roll angle developed, while the pitch angle and control column movements were more pronounced than on the other landings. For the Atlanta and Los Angeles landings, the air/ground discrete indicated “air” then a second later indicated “ground” and remained “ground.” Probable Cause: The pilot’s improper flare which resulted in a bounced landing.