The WRAF, Women's Royal Air Force, was founded in Britain in1918 as an auxiliary to the Royal Air Force, enabling women to take various roles at air force bases (and thus free up men for the front). Though the majority of the over 32,000 women who served from 1918-1920 were employed as clerks and typists, all kinds of trades and roles became open to women. Awesome women, of course!
For more information, the RAF museum has a good blurb; I'm all about the pictures!
A member of the WRAF working on a plane propeller. Source
A WRAF motorcyclist. Source
Taking a tea break. Source
A woman driver serving with the RFC (precursor to the RAF). Source
WRAF mechanics working on a plane. Source
A WRAF officer with a dog mascot. Source
WRAF members in a RAF lorry. Source
Members of the WRAF on parade (with mascot!). Source