1930's Air Mail from Estonia to Finland

A registered air mail cover from Tallinn to Helsinki dated 5.9.1933. Air mail route between Tallinn and Helsinki was spotty at best in 1933 but a daily flown route operated during the time period 1.5.1933 and 30.9.1933. Letter rate from Estonia to Finland was 15 senti between 1.1.1933 and 31.12.1934. Air mail surcharge to Finland for letters was 10 senti for each 20 grams since 1.7.1930. The registration fee of letters to Finland was 15 senti since 31.12.1928. Total rate should be (15 + 10 + 15) 40 senti. The letter therefore has a correct rate. The arrival post mark indicates an arrival time of seven in the evening. The plane arrived in Helsinki at approximately 17.40 so the arrival time is as expected. The blue 10 senti Song Festival was issued in 29.5.1933. The yellow 15 senti Coat of Arms stamps were issued much earlier.

A registered air mail cover from Tallinn to Helsinki dated 12.5.1937. Letter rate to Finland was 15 senti between 1.5.1937 and 1.4.1939. Air mail surcharge of letters to Finland was 10 senti for each 20 grams since 1.7.1930. Registration fee of letters to Finland was 15 senti since 31.12.1928. The stamps on the letter form a sum of 55 senti. The below letter is therefore 5 senti overpaid for the lowest weight class registered air mail letter. Incorrect rate. The 15 senti red president Päts stamp was issued in 25.3.1937 so this is a rather early use of it in an air mail letter.