By December 1941, Bader became the first woman in the RAF to qualify as an instrument repairer, First Class, pioneering a new technical trade for women.
By 1 December 1941, Lilian Bader had completed rigorous training and qualified as an instrument repairer, First Class—becoming the first woman in the Royal Air Force to achieve this technical qualification. The trade of instrument repairer had only recently been opened to women in the RAF around 1940, as the demands of total war forced the military to expand women's roles beyond traditional clerical and domestic work into skilled technical fields.
Bader's achievement was significant not only as a personal triumph but as a demonstration that women—and specifically a Black woman facing compounded prejudice—could master complex technical work essential to the war effort, including the calibration and repair of aircraft instruments critical to pilot safety and mission success.
Her qualification led to her promotion within the WAAF ranks, eventually rising to Leading Aircraftwoman and later Acting Corporal. This pioneering technical role placed her among a small vanguard of women reshaping perceptions of female capability in the armed forces. Her legacy is commemorated by institutions such as the RAF Museum and King's College London, who cite her as a foundational figure in the history of women's technical service in the British military, and as an early example of a Black woman excelling in a skilled, non-traditional wartime role.