In May 1926 Dowding was appointed director of training at the Air Ministry. He was appointed a Companion of the Order of the Bath on 2 January 1928 and promoted to air vice-marshal on 1 January 1929. Trenchard sent him to Palestine and Transjordan to study security problems caused by Arab–Jewish unrest: his reports, which gained Trenchard's approval, were a cause of further career advancement. Dowding became Air Officer Commanding Fighting Area, Air Defence of Great Britain in December 1929 and then joined the Air Council as Air Member for Supply and Research in September 1930. One of his first responsibilities in this post was the approval of the granting of a certificate of airworthiness to the R101 airship shortly before it set off on its ill-fated voyage to India; he later said "I think I was wrong not to insist on much more extensive trials and tests" and that his decision had been based on optimistic technical advice. Dowding's time in this office coincided with a period of rapid development in aircraft design and a growing fear that another major war was on the horizon. Although without scientific or technical training, he displayed a great capacity for understanding technical matters. He was promoted to air marshal on 1 January 1933 and advanced to Knight Commander of the Order of the Bath on 3 June 1933.