Noise is inherent in many mechanical systems. Small noise perturbations can lead to abrupt changes in the behavior of nonlinear systems that are sensitive to perturbations. Using statistical methods, we are exploring changes in system behavior in response to a noise input. We are focusing on rotational systems that have nonlinear characteristics such as turbines and fans. These studies are used to identify how system behavior is affected by the inherent noise, as well as to explore the potential use of noise input to avoid large deformations that could lead to mechanical failure.