Rebecca Sparling was an expert in the field of metallurgy and nondestructive testing. She gained practical metallurgical experience during the Great Depression through a series of manufacturing, foundry, and automobile plants as a metallurgist and as a consultant from 1931 to 1943. She wrote the comprehensive 1944 revision of the American Malleable Iron Handbook that was used as an industry standard and textbook. Sparling was a leader in the aerospace industry when there were few women in engineering. She was Chief Metallurgist at Northrop Aircraft from 1944 to 1951, and then a Staff/Design Specialist at Convair/Pomona from 1951 to 1968. Sparling pioneered the application of immersed ultrasonic inspection for gas turbine parts and was an industry leader in developing liquid dye penetrant surface inspection methods commonly used in the aerospace industry. She published more than 30 articles in technical and professional journals. After Sparling received the Society of Women Engineers’ Achievement Award in 1957, she became more active in the community. Upon formally retiring in 1968, Sparling became a community and environmental activist.