USSR
Sg:SU 811 - overprinted in red - (18 АВГУСТА день авиации СССР)
| Country: | USSR |
| Type: | Postage stamps |
| Series: | Aviation Day |
| Nominal: | 10 k |
| Year: | 1939 |
| Size: | 37 x 26 mm |
| Perforation: | comb 12 x 12½ |
| Mintage: | 500,000 |
