Združene države
Sedaj prikazano: Združene države - Znamke letalske pošte (1918 - 2012) - 2 znamke.
1991
William T.Piper
17. maj WM: Nič Perforacija: 11
![[William T.Piper, tip CW]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/CW-s.jpg)
1993
William T. Piper - Hair Touches Top Edge of Design
13. julij WM: Nič Perforacija: 11¼
![[William T. Piper - Hair Touches Top Edge of Design, tip CW1]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/CW1-s.jpg)
