 At first, it was assembled from a hodge-podge collection of civilian aircraft commandeered or donated and converted to military use.A variety of obsolete and surplus ex-World War II combat aircraft were quickly sourced by various means – both legal and illegal – to supplement this fleet.The backbone of the IAF consisted of 25 Avia S-199s (purchased from Czechoslovakia, essentially Czechoslovak-built Messerschmitt Bf 109s) and 60 Supermarine Spitfire LF Mk IXEs, the first of which, "Israel 1" was locally assembled from British abandoned spare parts and a salvaged engine from an Egyptian Spitfire with most of the rest purchased from Czechoslovakia.