Several methods have been formulated to predict the onset of e utter during e ight testing. These methods have been demonstrated using data from simulations; however, a rigorous evaluation that includes data from e ight testing must be performed. The ability of several methods to predict the onset of e utter by analyzing data from e ight tests of the aerostructures test wing is evaluated. The evaluated methods include data-based approaches that use damping extrapolation, an envelope function, the Zimmerman‐ Weissenburger e utter margin, and a discretetime autoregressive moving-average model. Also, a model-based approach that uses the π-method e utterometer is evaluated. The data-based methods are demonstrated to be unable to predict e utter accurately using data from low-speed test points, but converge to the accurate solution as airspeed is increased. Conversely, the e utterometer isdemonstrated tobeimmediatelyconservativeusing data from low-speed testpoints,butthesepredictionsremain conservative and do not converge to the true e utter speed as the envelope is expanded. The operation of a e ight test should note theproperties of each method to perhaps adjust test points based on the predicted e utter margins.