Incident Description
During the extension of the landing gear, the flight crew experienced a loud and very noticeable jolting of the aircraft. Shortly thereafter, they observed that a portion of the right main landing gear had punctured the upper surface of the right wing. The crew declared an emergency and subsequently performed an uneventful landing.
Investigation Findings
An investigation determined that the right main gear actuator support link, part number 65-19657-5, had become corroded and failed. This failure allowed the outboard end of the main gear actuator beam to puncture the upper wing panel. Additionally, a hydraulic line was severed, disabling the 'A' hydraulic system.
Maintenance Records
Examination of maintenance records from the previous aircraft owner revealed an erroneous indication that in 1971, the failed part had been replaced with a newer link assembly, part number 19657-11, which did not require an inspection. Consequently, the required inspections specified in Airworthiness Directive (AD) 68-17-01, regarding the failed link, had not been complied with by the new owner. Boeing had issued Service Bulletin 727-32-306, which recommended that link assemblies with part numbers 19657-5 (as well as -4, -8, and -13) be removed from service and discarded.