Thailand. (Domestic Air Mail Service). 1926. Air Mail envelope addressed to Ubol (Udon) bearing Siam SG 159, 2s on 14s ultramarine, "Victory" SG 188, 2s yellow-brown, SG 211, 2s chocolate/ yellow and SG 213, 3s red-brown tied by small type "Aeroplane" of Nagor Rajasima dated '7.2.26', with 'Mit Flugpost/ By Air Mail' label and Ubol small plane receiver '9.2.26'.
Carried on the Royal Aeronautical Service from Nagor Rajasima to Ubol. A nice franking with 'Victory' usage.