British Empire - Day 6

1933 Imperial Airways special flight cover Calcutta to Athens, Greece, franked with 1/2a, 1a, 8a tied by cachet “Calcutta – Karachi First Airmail”, with a special blue cachet also on front showing biplane with Greek lettering above and below. An extremely rare flight cover from Imperial Airways 11 July (Newall notes 20 carried), with Athens receiver on back 15 VII 33.