Flap peening (FP) is a cold working technique used to apply a compressive force using small shots, this will lead to enhance the surface properties that it can sustain for long life during working conditions. In this study, several aircraft aluminum alloys materials namely; 2219 T6, 2024 T6, 7075T6, and 6061 T6 were flap peened under different rotational speeds. The effect of rotational speed on the average surface roughness (Ra) and average surface micro hardness have been investigated. As seen by the Scanning Electron Microscope SEM phots that the hardness of peened layer is increased. It was found that as the flap peening speeds increase the percent change in surface roughness (Ra) increases, and the percent change in surface micro hardness decreases. The maximum increase in Ra occurs in 2219 T80 and the minimum in 6061 T6 alloys, and for hardness, it is reported that the maximum occurs in 6061 T6 and the minimum in 2019 T80 alloy.