▁Western ▁Front ▁in ▁Europe . ▁ ▁After ▁additional ▁training ▁in ▁England , ▁he ▁was ▁assigned ▁to ▁the ▁ 8 th ▁Training ▁Squadron , ▁Australian ▁F lying ▁Cor p . ▁and ▁served ▁in ▁Wend over ▁from ▁ 2 4 ▁October ▁ 1 9 1 7 , ▁Cir enc ester ▁in ▁January ▁ 1 9 1 8 ▁and ▁then ▁to ▁Le ighter ton ▁until ▁April ▁ 1 9 1 9 . ▁During ▁this ▁time ▁he ▁was ▁promoted ▁to ▁Air ▁Mechan ic ▁ 1 st ▁class . ▁ ▁He ▁worked ▁on ▁the ▁S op worth , ▁P up , ▁Cam el ▁and ▁S ni pe ▁aircraft . ▁ ▁When ▁the ▁squad ron ▁was ▁dis band ed ▁and ▁he ▁returned ▁to ▁Australia . ▁ ▁Cro ok ▁was ▁dem obil ised ▁from ▁the ▁Australian ▁F lying ▁Cor p ▁on ▁ 6 ▁May ▁ 1 9 1 9 . ▁ ▁Work ▁and ▁industry ▁After ▁comple ting ▁military ▁duties ▁Cro ok ▁returned ▁to ▁the ▁Victor ian ▁Rail ways . ▁ ▁After ▁a ▁short ▁time ▁Cro ok ▁joined ▁a ▁small ▁company ▁that ▁soon ▁was ▁taken ▁over ▁by ▁Australian ▁Elect rical ▁Indust ries . ▁ ▁To ▁advance ▁his ▁career , ▁Cro ok ▁decided ▁to ▁gain ▁experience ▁in ▁the ▁United ▁States ▁of ▁America , ▁setting ▁sail ▁in ▁August ▁ 1 9 2 1 . ▁He ▁gained ▁experience ▁in ▁a ▁number ▁of ▁large ▁elect rical ▁engineering ▁fir ms ▁including ▁doing ▁draft ing ▁work ▁in ▁Chicago , ▁before ▁going ▁to ▁the ▁UK ▁for ▁a ▁year ▁to ▁do ▁a ▁special ised ▁course ▁with ▁Metropolitan - V