1. A method for creating a smooth speed profile while meeting a required time of arrival (RTA) for an aircraft in a multi-segmented flight plan including a preceding region with a first predetermined speed pad and a speed constrained region with a second predetermined speed pad, comprising steps of: determining whether the speed constrained region is engaged based at least in part on a proximity to the speed constrained region; if the speed constrained region is engaged, determining a revised second speed pad for the speed constrained region; if the speed constrained region is not engaged then assigning a default speed pad as the second predetermined speed pad for the speed constrained region; compiling a new speed profile that is defined based one of the revised second speed pad and the default speed pad for the speed constrained region; and causing the aircraft speed to conform to the new speed profile.