Great Britain 1931 Experimental Flight “CITY OF CAIRO” CRASH Cover Netherlands Indies

Cover franked with 4d and 1/- KGV, tied by London machine cancel (Apr 3), Imperial Airways Experimental Flight to Australia, carried on the DH66 Hercules "City of Cairo", crashed on the leg from Karachi and Koeping in the Netherlands Indies, with mail being forwarded onwards to Darwin by Kingsford-Smith in the "Southern Cross", Darwin c.d.s. backstamp (Ap 31), scarce and fine.