You can check VAS (space left). Only with registered FSUIPC. 1-Open the FSUIPC setup screen. Go to the “logging” tab, and in one of the “specific value checks” enter the value 024C (first character is zero, not the letter”O”. 2-Change the “type” for that value from S8 to S32. 3-Click on the checkboxes to display the value either at the upper window bar, or within the main FSX screen. Now save and exit. Going forward, you will have a continuously-updated readout in-game of free VAS remaining.