It seems to have been completing two sorties each day, with the morning flight using the radio callsign of "Shadow 11", while the afternoon flight is usually "Shadow 21".
Meanwhile, also down at Gladstone Airport, the visiting GoJet / Air Affairs (Australia) Learjet 35A and Learjet 36A bizjets continue to fly sorties also in support of operations to the South during joint Military Exercise Talisman Sabre 2019 (TS19).
It appears that they fly in various combinations of pairs with Learjet 36A bizjet VH-SLF and Learjet 35A bizjets VH-SLD, VH-LFA and VH-LJJ completing two sorties each day in these pairs also in the morning and afternoon.
They have been heard flying as "Bosun 11" and "Bosun 13" flights of two in the mornings, while in the afternoon, the two pairs fly as "Bosun 21" and "Bosun 23".
Sincere thanks to the local plane spotters for taking the time capture and send through these great photos and video!
Photos and video taken by Daniel Bishop, 'IAD' and Terry Purcell ©️