The influence of angle of attack on the helicopter blade-vortex mechanism of interaction is investigated using large eddy simulation (LES). The LES technique provides a promising tool for obtaining the unsteady wall-pressure fields, aerodynamic coefficients and the acoustic source functions. A large eddy simulation is carried out for a two-dimensional Blade-Vortex Interaction (BVI) problem, for a chord based Reynolds number of 1.3x106. Computations are carried out to investigate the influence of angle of attack (α = 0θ, α = 5θ, α = 10θ) on the aerodynamic coefficients and acoustic field.