Alan Blumlein made a major contribution to radar development during the Second World War but was tragically killed in an air crash while engaged on tests on the H2S radar prototype. Blumlein's first post was with the International Western Electric Corporation in 1925, working on interference in telephone lines. In 1929 he joined Columbia Gramophone's Research Department, which merged with HMV in 1930 to form EMI.
Most of Blumlein's inventions were made during his work with EMI - he took out 132 patents while with them. He made significant contributions to recording and television, including a system of stereo recording. He was EMI's Senior Engineer on the outbreak of the Second World War, which meant that he was transferred immediately to war project work.
He adapted his stereo work to develop an acoustic direction finder for aircraft, and he worked on aircraft radar systems. At first these he was involved with airborne interception radar but became closely involved in the H2S project to develop an aircraft radar system that could project a map of the ground onto a screen as the aircraft flew. Blumlein was mainly responsible for the circuitry, especially for data handling and display.
H2S was not ready when Blumlein and two other top EMI scientists were killed in the crash, so news of his death was kept to a bare minimum to prevent the Axis powers realising that Britain's radar programme had received a major setback. However, the H2S system, closely based on Blumlein's work, was eventually brought into use and proved a valuable weapon in Coastal Command's war against submarines.