1928. First Flight envelope from Texas addressed to Bangkok, Siam bearing United States Yvert 228, 1c green and Yvert 229, 2c red and Air Mail Yvert 10, 10c blue tied by San Antonio, Texas roller 'Feb 6' with framed 'First Flight/Inaugurating/Air Mail Service/Dallas-San Antonio/Air Mail Route/San Antonio, Texas' in violet (signed by the pilot) with Dallas arrival and forwarded via Omaha/Neb and Washington with Bangkok arrival '14th Mar 1928'. Scarce.