''TSTC WACO RAP, TX 7-5-2023
N579NA G.550 L3HARRIS for?''
This is most probably N579GA (5579).
Destined to be a new EC-37B for the USAF.
Also, in 2022 noted at Waco: N591GA (5591)
An overview of the military G550 status can be found at my website
www.gulfbiz.nl