Accurate dynamic modeling of helicopter aeromechanics is becoming increasingly important, as progressively stringent requirements are being imposed on rotorcraft control systems. System identification plays an important role as an effective approach to the problem of deriving or fine tuning mathematical models for purposes such as handling qualities assessment and control system design. In this paper, the problem of deriving continuous-time models for the dynamics of a small-scale quadrotor helicopter is considered. More precisely, the continuous-time predictor-based subspace identification approach is adopted and the results obtained in an experimental study are presented and discussed.