r. Chambers was inducted June 29, 1941 and entered the Army Air Corp as a First Lieutenant. After completing pilot training for a flight surgeon, he was first assigned to the Flying Tigers Unit, the 308 Bombardment Group. At Wendover Field in Utah, he was reassigned to the 29th Bombardment Group and then was assigned to the Air Force Service Command for duty. While at Wendover Field, Utah, he received "confidential" orders to report to the Army Base. He had made captain and held the designation of Train Commander. On Dec 21, 1942, Captain Chambers qualified as an Aviation Medical Examiner. He then received orders (secret) that the 308th Bombardment Unit (the Flying Tigers) would proceed from Karachi, India to Chabun, India, then proceed to Kunming, China. Captain Chambers was assigned as a Flight Surgeon under General Claire Lee Chennault. While he was in China, he received injuries to his right leg during a Japanese bombing raid. He was transported to West Palm Beach for treatment of his injuries as well as treatment for malaria and amebic dysentery. On 2 Dec 1943, John was declared fit for duty and was assigned to the Medical Dept as a Flight Surgeon but it was noted that assignment to tropical theaters was not recommended. On 31 May 1944, he was promoted to Major. He stayed on active duty after the war ended to help process soldiers and airmen out of the Army Air Corp.