This paper presents and describes the results of an experimental study into the control of separated flow over a NACA0015 airfoil over a range, of angles of attack at a Reynolds number of 3 × 104. The study was carried out in the LTRAC 500 mm × 500 mm water tunel. The separation control is actuated using a planar zero-net-mass-flow (ZNMF) jet at the leading edge of the airfoil. The ZNMF micro-jet flow is generated using a piston-cylinder arrangement connected to a skotch-yoke mechanisms that is driven by a computer controlled stepper motor. The parameter range for the planar ZNMF jet ranged from nondimensional frequency of 0.5 to 1.5 and blowing coefficients up to 0.2. A six component force transducer was used to measure the lift and drag force on the airfoil. Planar laser induced fluoresence (PLIF) using Kyton red dye and Nd:YAG laser illumination was used for the flow visualisations. Multigrid cross-correlation digital PIV (MCCDPIV) with pulsed Nd:YAG laser planar illumination was employed with digital imaging of 4008 px × 2672 px to measure instantenous velocity fields.