Aircraft systems and methods with multiple SAP speed profiles

A system for controlling speed of a vehicle, comprising:

• a navigation system configured to generate navigation information;
• and
• a guidance system coupled to the navigation system and configured to generate actuator commands for the vehicle based on the navigation information in accordance with a travel plan, the travel plan having a current speed profile with a plurality of regions to a fix point with a Required Time of Arrival (RTA), each of the regions having a respective speed adjustment parameter (SAP) and a respective SAP value relative to a nominal speed profile, wherein the guidance system includes an RTA module configured to
• determining an arrival time error (ATE) for a projected trajectory according to the current speed profile;
• and
• sequentially select and modify, when the ATE is greater than a threshold, the respective SAP values of individual regions of the plurality of regions based on a priority order of the regions to generate modified speed profiles as the current speed profile implemented by the guidance system, wherein the priority order of the RTA module is high to low when decreasing a magnitude of the respective SAP value and low to high when increasing the magnitude of the respective SAP value.