The Ethiopian flights from Addis to Newark (tech stop in Rome, no traffic rights at all, neither Ethiopia to Rome nor Rome to the US) continue to Dulles, so EWR and IAD are both served by the same flight (no traffic rights between EWR and IAD either obviously). Aircraft type is 767.
Something that really irritates is seeing "Worldwide Service" on United aircraft. Doesn't say much for America's view of the world. "Worldwide Service" like the "World Series". Sorry, a few cities in western Europe and a few in Asia plus the Americas do not "Worldwide Service" make. Someone should point to Africa on a map in a UA planning meeting someday or show them a BA/LH/AF/MH/RG/CX/KL/any other half decent airline's route map. Or are UA about to go out of business? Hell, Alitalia fly to more continents than UA.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz