Around 1970 I took a Pan Am B747 flight from Heathrow to Beirut which was going via Frankfurt and Istanbul. I seem to recall it was their round the world flight.
After spending god knows how many hours on the ground at Frankfurt because they could not close one of the cargo hold doors we bypassed Athens as crew would have been out of hours much to the horror of Israeli pax who were due to disembark at Istanbul.
Guess BOAC did similar flights too.