1912 (July 29), Demonstration Flight at Hareskov, cover to Copenhagen, franked by four definitive stamps, boxed ''Hojsommerfesten. I Hareskov 1912.'' confirmation and oval merchant's markings in violet, VF, Est. $100-$150 (Image)

1919 (September 13), Naestved to Storehedinge Pioneer Flight by Otto Reichter, cover franked by King Christian X 10o red and bearing semi-official vignette of 50o black on rose paper (Sanabria #502), tied by Naestved date stamps, the same date Storehedinge arrival is alongside, mostly VF, Mueller #15, Est. $500-$600 (Image)