Friend and Biographer of George Mallory.
Born on 29 April 1886 in Hampstead, London, the sixth of the seven children of William Arthur Pye, wine merchant, and his wife, Margaret Thompson. Educated at Tonbridge School and Trinity College, Cambridge and was placed in the first class of the mechanical sciences tripos in 1908. In 1909 C. F. Jenkin invited Pye to join him in Oxford and he was elected a fellow of New College in 1911.
During the First World War, Pye taught at Winchester College (1915–16), then worked as an experimental officer in the Royal Flying Corps on design and testing, and learned to fly as a pilot. In 1919 he returned to Cambridge as a lecturer, and became a fellow of Trinity where he met Henry Tizard and Harry Ricardo. This association led to important pioneer work on the internal combustion engine.
In 1926 Pye married Virginia Frances, daughter of Charles Moore Kennedy, barrister. They had two sons and a daughter.
Pye's The Internal Combustion Engine (2 vols., 1931–4) was published in the Oxford Engineering Science series, of which he became an editor. In 1925 he was appointed deputy director of scientific research at the Air Ministry. He succeeded him as director in 1937 and in the same year was appointed CB and elected FRS. During the early war years he became closely associated with the development of the new jet propulsion aircraft engine which he did much to encourage.
In 1943 Pye accepted the provostship of University College, London. Serious illness forced him to resign in 1951. He was knighted in 1952 and in the same year became president of the Institution of Mechanical Engineers.
Pye was an enthusiastic climber and in 1922 was elected to the Alpine Club of which he became vice-president in 1956. He was a friend of George Mallory's and on his and Andrew Irvine's loss he wrote: Those two black specks, scarcely visible among the vast eccentricities of nature, but moving up slowly, intelligently, into regions of unknown striving, remain for us a symbol of the invincibility of the human spirit.