Kammala jumla mai zuwa: A ranar 1 ga watan Agusta, 1915, an canza Mackinolty zuwa rundunar sojojin Australiya, don jagorantar wata ƙungiya ta wasu injiniyoyi goma sha uku a matsayin ƙarfafawa ga rundunar Sojan Sama ta Australiya da ke aiki a yakin Mesopotamiya. Ya bar Melbourne kwana tara bayan haka a cikin RMS "Persia", kuma ya isa Basra a ranar 1 ga Satumba. Tawagar Mackinolty nan da nan ta shiga Squadron 30 Royal Flying Corps (asali Mesopotamian Half Flight AFC), wanda ya koma garin Kut bayan da sojojin Daular Burtaniya suka kama shi a yakin Es Sinn. Unitungiyar ta shiga cikin Yaƙin Ctesiphon a watan Nuwamba, kuma ta shirya saukar da kayayyaki ga sojojin Biritaniya da na Indiya a
Kut a lokacin da aka kewaye shi daga Disamba 1915 har zuwa Afrilu na gaba.