I remember reading that ball turret gunners did not meet normal AAF minimum height and weight requirements but exceptions were granted for them. Likewise tiny people, mainly women, were highly sought for aircraft assembly jobs so that they could install wiring and hydraulic systems in very tight spaces inside the fuselage.
I've got a very small set of acetylene equipment that someone once told me would have been handy in some of the very small spaces he was required to work in the aircraft industry. He was a small man, under 5'5" I'd say.