In April 1939, with the threat of war increasing, Air vice-Marshall Charles Portal, head of the personnel department of the R.A.F. wrote:í Ö.should a war break out however, you can almost be sure we will gladly make use of your services as a pilot within a short time, provided the physicians give their consent." On September 3rd, 1939, the day Great-Britain and France declared war on Germany, Bader immediately wrote to Portalís secretary. Early October he received a telegram from the Air Ministry to the effect he had to report to the selection committee. He was declared medically fit but nonetheless he was informed he was eligible for a posting to ground service only. Air vice-Marshall Halahan, commander of Cranwell at the time Bader was stationed there, intervened for him and managed to have Bader examined by the Central Flying School at Upavon, Wiltshire. He reported there on October 15th . At the end of November he was declared capable to execute operational flights. He was posted to the C.F.S. for a refresher course on new types of aircraft.
On November 27th, 1939, Bader flew solo in an AVRO Tutor for the first time. During the following days, he flew other types of aircraft including the Fairey Battle, a light bomber and the Miles Master in preparation for the Spitfire and the Hurricane. He graduated at the end of January 1940. His flying skills were judged as excellent. On February 7th, 1940, he was posted to No. 19 Squadron at R.A.F. Duxford near Cambridge. Here he flew the legendary Supermarine Spitfire for the first time. Squadron commander was Geoffrey Stephenson, an old friend of his from his Cranwell period. Between February and May 1940, the squadron was involved in protecting convoys at sea and training attacks. Douglas Bader did not agree with the existing doctrines. He had more faith in simultaneous attacks by two or three aircraft, launched from great height and using the sun as cover. Due to his fine capacities, Douglas was soon appointed section leader.
In this period he crashed his Spitfire at take off because he had forgottten to set the propellor pitch correctly. His aircraft was a total write off and his protheses were severely damaged but physically, Bader was allright except for a head wound. He had to report to the station commander, Air vice-Marshall Trafford Leigh-Mallory, the future commander of Fighter Command. He expected to be reprimanded and got one but he was also told he was appointed flight commander of No. 222 Squadron R.A.F. and that he was promoted to Flight Lieutenant. 222 Squadron was also based at R.A.F. Duxford and was commanded by Herbert "Tubby" Mermagen, also an old friend of Baderís. Bader trained his men in his own specific manner, spending much time on individual attacks.