In 1922 Helmore was granted a permanent commission in the RAF and developed his interest in scientific research in aviation. He was also involved in the development of aerial refuelling, serving as copilot and hose handler on Sir Alan Cobham's pioneering flight from Portsmouth, England to India on 22 September 1934, also inventing the electrolytic process of forming flame or explosion traps. In 1931 Helmore was awarded the Groves Prize for Aeronautical Research. Helmore retired from the R.A.F. at his own request in 1937 to devote himself to research at Cambridge, but be returned to the active list in August 1939. His appointments included Wing Commander, Honorary Group Captain and Honorary Air Commodore.
As senior scientific adviser to the Chief of Air Staff from 1939, Helmore was chiefly concerned with defeating the nightbomber. Helmore with aeronautical engineer L.E. Baynes, nicknamed "The Baron", worked on the development of the Helmore/GEC Turbinlite was a 2,700 million candelasearchlight fitted in the nose of a number of experimental radar equipped Douglas Havocnight fighters by the British during the early part of World War II and around the time of The Blitz. The light was intended to be used to illuminate attacking enemy bombers for defending fighters accompanying the Havoc to then shoot down. Unfortunately certain practical difficulties brought the idea to nothing, but much of his work was subsequently incorporated in the Leigh light, an antisubmarine aircraft searchlight, which with the aid of radar was particularly deadly to Admiral Doenitz'sU-Boats. For the last four years of the war he was technical adviser to the Ministry of Aircraft Production, and was responsible for a number of other valuable inventions and, in 1942, he was selected as one of the eight members of the Brabazon Committee. Helmore's contribution, to Britain's war effort was not confined to scientific research. He had earlier broadcast such events as the Schneider Trophy air races and reviews, and during the war his accounts of the RAF's work were heard frequently. His most notable commentary was when he broadcast an eye-witness account of the D-Day landings in Normandy, the first 'live',, broadcast from over the invasion fleet on 6 June 1944, reporting overhead from an RAF Mitchell bomber. Helmore was Conservative Member of Parliament for Watford 1943–1945.
Post war
After the war Helmore entered industry, being technical director to Castrol, a scientific consultant to ICI and director-general of the Aluminum Association. In 1947 Helmore was invited by the Minister for Civil Aviation to become the chairman of the Brabazon Committee, to consider the certification of aircraft and approval of equipment. In addition he was the vice-chairman of a committee set up to review the licensing, recruitment and training of civil aviation personnel. Helmore was a keen yachtsman, owning the schooner Allegro from 1929 to 1963. Helmore married twice. His obituary in The Times records that he left two sons and three daughters of his first marriage but other reports say he had four children, Peter, Patrick, Peggy and Pamela. Peggie, his eldest daughter married Cuthbert Scott in 1942.
