This embroidered wing was worn typically on an armband on the pilot's left arm thought it could be sewn to the sleeve, as well.  This design is for a non-commissioned officer.  It depicts a two-bladed propeller flanked by 2 wing pinions in red silk and wing feathers in gold cannetille, a style of embroidery with gold wire, on a black background. See Bartlett, pages 343, no. 4,6,7 and 344, no.5.