"Shep's" career began with Vickers-Armstrongs in the gun manufacturing industry, and on the outbreak of the 1914-18 war he joined the Honourable Artillery Company, transferring to the R.F.C. in 1916. Among the squadrons with which he served were No. 102 (F.E.2bs) and No. 37 (Camels), and he flew on night operations against Zeppelins. He left the Service in 1918 but
rejoined it in 1921, serving in England and in Egypt until 1929, when he was placed on the Reserve. Thereafter, he was C.F.I, to Phillips and Powis, Reading, and was subsequently with National Flying Services and managed the Nottingham Flying Club. In October 1931, Capt. Shepherd made his first flight for Rolls-Royce, testing a Fairey IIIF with a Kestrel engine. During the next three years he flew regularly for the company, and when they started their own flight establishment at Hucknall in 1934, Shepherd was appointed chief test pilot, a post which he held continuously until 1951.
During the post-war years he was, of course, mainly concerned with gas-turbine flying. He was the first man to fly on Nene and Avon engines—in the Lancastrian flying test-bed; he flew this aircraft at the 1946 S.B.A.C. Show. In 1951—in which year he had a serious illness and two
major operations—he relinquished full-time test flying and was appointed flying consultant to the Rolls-Royce management. The old urge remained, however, and when the most unconventional aircraft ever produced—the Rolls-Royce "Flying Bedstead"— was ready for testing, he made a special request that he should be allowed to conduct the initial work. "Shep" made the first flight on August 3rd 1954.
In 35 years of flying, he handled 77 different types of aircraft and logged over 8,000 hours. Official appreciation of his outstanding work as a test pilot, and in particular of his flight development work on the Merlin engine, came in 1946, when he was appointed O.B.E.