Air Vice Marshal Hari Chand Dewan was commissioned in the Indian Air Force in 1940. He saw active service in Burma during World War II. He has held various command and staff appointments with distinction. He attended the Flying Instructors Course in the United Kingdom in 1942 and the RAF Staff College Course, Andover, in 1948-49. He also attended the National Defence College Course in 1961-62. After holding the appointment of Senior Air Staff Officer at Headquarters, Western Air Command, he was posted as Director of Operations (Transport) at Air Headquarters where he had to handle a variety of difficult problems relating to air transport support. During the Chinese aggression in 1962, he planned the airlift programme involving not only the transport fleet of the Air Force but almost the entire fleet of the Indian Airlines and non-scheduled operators. He was also instrumental in arranging compilation of navigation data for airfields and the revision of aeronautical charts. During his tenure as Air Officer Commanding-in-Chief, Central Air Command, he has made marked improvement in the operational potential of the fighting elements of the Command. As Air Officer Commanding-in-Chief, Maintenance Command, since 1st April 1968, he has shown a great deal of energy and initiative in meeting the maintenance and supply requirements of the operational commands.