Thailand. (Domestic Air Mail Service). 1923. Air Mail envelope addressed to 'The Oriental Stamp Co. Bangkok' bearing Siam SG 214, 5s carmine/ pink (pair) tied by large type "aeroplane" of ROI ET dated '2.2.23', endorsed 'By Aerial Post' with Bangkok/ 2 arrival '10.3.23' (date error) and large type "aeroplane" receiver '10.2.23'.
Carried on the weekly flight of the Royal Aeronautical Service from Roi Et to Bangkok.
The large Aeroplane hand-stamp much scarcer than the small type.