ass is ' ▁wh aling ▁enter pr ises . ▁Sch acht ▁had ▁previously ▁been ▁connected ▁with ▁On ass is ' ▁Sa udi ▁Arab ian ▁de als . ▁ ▁Olympic ▁Air ways ▁▁ ▁In ▁ 1 9 5 6 , ▁Greek ▁air lines ▁in ▁general ▁faced ▁economic ▁difficulties , ▁where by ▁companies ▁like ▁T AE ▁were ▁affected ▁by ▁strik es ▁and ▁c ash ▁short age . ▁The ▁Greek ▁government ▁decided ▁to ▁give ▁this ▁and ▁other ▁companies ▁to ▁the ▁private ▁sector , ▁and , ▁on ▁ 3 0 ▁July ▁ 1 9 5 6 , ▁On ass is ▁signed ▁a ▁contract ▁grant ing ▁him ▁the ▁oper ational ▁rights ▁to ▁the ▁Greek ▁air ▁transport ▁industry . ▁When ▁On ass is ▁heard ▁during ▁the ▁negoti ations ▁that ▁he ▁would ▁not ▁be ▁able ▁to ▁use ▁the ▁five ▁Olympic ▁rings ▁in ▁his ▁logo ▁due ▁to ▁copy right ▁issues , ▁he ▁simply ▁decided ▁to ▁add ▁a ▁sixth ▁ring . ▁▁ ▁Operation ▁effectively ▁started ▁in ▁ 1 9 5 7 , ▁with ▁one ▁DC - 4 , ▁two ▁DC - 6 s ▁and ▁ 1 3 ▁DC - 3 s . ▁The ▁following ▁year ▁saw ▁ 2 4 4 , 0 0 0 ▁passengers ▁transport ed . ▁The ▁agreement ▁last ed ▁until ▁ 1 0 ▁December ▁ 1 9 7 4 , ▁when ▁a ▁number ▁of ▁factors ▁( nam ely , ▁a ▁series ▁of ▁strik es , ▁short age ▁of ▁passengers , ▁fuel ▁price ▁increase , ▁and ▁a ▁law ▁from ▁the ▁new ▁Greek ▁government ▁forb idd ing ▁Olympic ▁Air ways ▁to