 Walker was promoted to brigadier general on 17 June 1942 and was transferred to the Southwest Pacific Area , flying to Australia in the company of Brigadier General Ennis Whitehead , another newly promoted brigadier general . The commander of Allied Air Forces there , Lieutenant General George Brett , aware that he would soon be replaced , sent the two newcomers on an inspection trip . Walker learned a great deal . He joined three combat missions over New Guinea , experiencing for himself the difficulties that his aircrews faced . He also experienced an air raid in Port Moresby . For this , Walker was awarded the Silver Star . His citation read : 
