Eileen Muriel Younghusband, BEM (née Le Croissette; 4 July 1921 – 2 September 2016) was a filter officer in the Women's Auxiliary Air Force in World War II. She worked in the filter room, a top-level British air defence hub which assessed radar reports in order to give air raid warnings. Later, while posted to Belgium, she was part of a team of mathematicians who alerted Allied forces to the location of V-2 rocket launch sites. Younghusband completed a university degree at the age of 87 and subsequently published three books about her wartime experiences: two memoirs and one children's book. Early life Eileen Le Croissette was born in London in 1921. She left school shortly after her 16th Birthday and worked in the head office of Scottish Provident in London, who provided life assurance. She worked as an au pair in France after her German teacher suggested she gain experience in speaking French and German to help set up his new business, the 'School Travel Service'. She worked for the Boucher family until Hitler remilitarised the Rhineland, when she returned home. On this journey she encountered many fleeing Jews. Upon her return, she worked for Corke Sons & Co. as a secretary. Whilst working here, she visited Germany in the Summer of 1939. She went to a paper factory connected to her employers but also to a professor known to her German teacher, as she still had hope of the School Travel Service. She returned in early August 1939, 3 weeks before war began. War begins Eileen Le Croissette was invited back to work at Scottish Provident, after conscription led to a shortage of men, and was a valued employee, with rooms in the city. Le Croissette experienced the first Blitz on 24 August 1940. This led to her deciding to join the WAAF. Wartime service Eileen Le Croissette joined the Women's Auxiliary Air Force (WAAF) in 1941 at the age of 19, and was trained at RAF Innsworth, near Gloucester, and RAF Leighton Buzzard. Commissioned as an assistant section officer in November 1941, and promoted to section officer in October 1942, she was posted to 10 Group Fighter Command at RAF Rudloe Manor, Corsham, near Bath, where she was deployed as a filter officer. In this post, she was responsible for assessing the information gleaned from Chain Home coastal radar stations, estimating position, height and number of enemy