This study evaluates the role of supercomputers in large-scale fluid/structure analyses of aerospace vehicles, with an emphasis on computational aeroelasticity dominated by complex fluid/structure interactions. The information presented is primarily based on responses to a web-based survey that was designed to capture the nuances of high-performance computational aeroelasticity and, in particular, its use of parallel computers. Survey responses were solicited from leading application engineers who use NASA and DoD supercomputing resources. A method of assigning a fidelity-complexity index (FCI) to each application is presented, and case studies of major applications using HPC resources are summarized.