Australia 1931, First flight Australia England - 2 covers:

• KLM, Fokker FVIIA/3m trimotor Registered first flight cover sent from Melbourne, Australia and addressed to London, England cover bearing multi franking of 1931 Kingford Smith's World Flights 6d  in a block of 6 plus singular (Mi:AU 112 ; Yt:AU PA3, SG 123) and 3d (Mi. 96; SG 122) all stamps are tied by Register postmark May 22. On the reverse is the cachet for the "Australia-Netherlands Indies Special Air Mail Flight - May 1931 Melbourne to Batavia". This flight left Melbourne on May 27, 1931 and arrived in Batavia on May 27, 1931. 
• April 1931 Imperial Airways, First official flight British Commonwealth Australia - England, air letter bearing mixed franking of 1931 Kingford Smith's World Flights 2d, 3d, 6d (SG 121-123) & 1929 Airmail 3d. (Mi:89, SG. 115) both tied by 'Toorak VIC / April 22 1931', On reverse 41/2d  in mixed franking (SG 116 & SG 117 x2) also tied by Toorak  April 22, also rubber hand stamp in violet commemorating the 'FIRST OFFICIAL AIR MAIL FLIGHT' from Melbourne to London.