Sir Francis McLean was born in Birmingham, England. He designed high-power radio transmitters for Western Electric in England before moving in 1928 to work for Standard Telephones and Cables in Paris. From there he traveled throughout Europe, designing high-power radio and telephone equipment.
He joined the BBC in 1937. During World War II, McLean was involved in producing mobile equipment for war correspondents. He was assigned to the Psychological Warfare Division of Supreme Headquarters Allied Expeditionary Forces as chief engineer. In August 1944 he was the first BBC man to enter Paris. He started French radio transmitters in the wake of the retreating Germans and went on to resurrect Radio Luxembourg after the region had been liberated by U.S.
When he returned to the BBC he became an advisor to the new Radio Pakistan. He became deputy chief engineer in 1952, deputy director of engineering in 1960 and finally the director in 1963. In 1967 he was knighted for his services to broadcasting.
He chaired the British Standards Institution Telecommunications Industry Standards Committee between 1960 and 1977, and in 1974 headed a Royal Commission on FM broadcasting in Australia. He settled in Berkshire, England, where he kept a small flock of sheep.