Don't count on the aircraft being the one stated - my ADD-LHR return in April was meant to be on the 787, but when I went to check in online it turned out to be a 777. You can't check in online from LHR, so you won't know until you get to the airport. Tip is to arrive VERY early as Ethiopian are known for overbooking. I arrived 2 1/2 hrs early and was OK, my friend arrived 30 mins later and was placed on standby. She did get on the flight, but it was not a reassuring hour or so waiting to know. At LHR Ethiopian is all self-service check in. From ADD you can check in online for the return. Try to get a window seat on the right hand side. For a good part of the flight we followed the Nile through Sudan and into upper Egypt.