Cathleen Morawetz was a mathematician and NYU professor whose research on the motion of fluids and waves was relevant to supersonic aircraft wing design. Her file describes a monthlong visit to the Soviet Union in 1963 as part of an Exchange Agreement, as well as FBI efforts to interview her (and apparently share technical information with her) without alerting her to the identity of a particular Bureau informant.
New York Times obit: Cathleen Morawetz, Mathematician With Real-World Impact, Dies at 94