Good Idea Comes to Fruition: The F/A-18 Center Barrel Replacement- Plus Program

摘要

Naval jets live hard. That point is well illustrated by the U.S. Navy's premier fighter/attack aircraft, the F/A-18 Hornet. Achieving initial operating capability in 1984, the Hornet was designed to fly 6,000 hours and accumulate 2,000 arrested landings and 8,300 total landings. Day after day, the jets are stressed to the edges of the engineering envelope, and the toll of repeated oscillating G-forces isn't easily predicted when the structures are initially designed. Such destructive forces have their greatest effect on attach points, where the aircraft's wings and main landing gear join its fuselage frame. Those attach points, along with the surrounding fuselage section, are dubbed the aircraft's center barrel. One expression of the destructive toll is a metric called wing root fatigue life expended (WRFLE), and it is calculated through a complicated engineering analysis that determines each aircraft's remaining structural integrity at the critical wing attach points. In 1991, a Hornet with low flight hours experienced an excessively hard carrier landing that caused what was considered irreparable damage to the aircraft's center barrel section. The crippled Hornet was shipped to the Navy's Fleet Readiness Center SW in San Diego, Calif., for damage assessment. The damage was so severe that it was judged to be beyond even the FRC's capabilities. Industry repair estimates were as high as 50% of the original procurement cost, and the time to design and build repair fixtures was forecast at 3 years. A team of depot engineers, technicians, and logisticians within FRC SW rose to the challenge to do what had never been done before. They developed the machinery and technology to remove and replace the damaged center barrel. The process, named the Center Barrel Replacement-Plus (CBR+) Program, transformed the Hornet community's views of the impact of WRFLE on an aircraft's serviceability and gave DoD valuable breathing space in developing a successor platform for the Hornet.