FSX Mission--SR-71 Record Speed Run 1. Welcome to this interesting but very tricky mission. Be sure that you have the instructions printed out and next to you otherwise you will have a lot of difficulties. Remember although this mission seems long, things happen very fast, seconds do play a major role in this mission. Due to the nature of the freeware Alphasim SR71, it is not known if the mission can be flown with the payware Alphasim SR71, but it should be worth a shot. By Robbie Albers.