Flew into Delgado this past month. A couple things about the airport travelers want to be aware of;
There are 2 terminals, 1/2 mile apart that make up the airport. Terminal 1 is the main terminal with all the shops, food, transportation etc. Terminal 2 is used as mainly a Europe destination hub, however, our flight from Dulles on TAP airlines parked here. Some Ryan Air and Vueling planes are loaded and deplane here also. The key point is planes here deplane onto the tarmac outside of terminal 2 and you are loaded onto buses to be moved to terminal one.
If you are going to Lisbon, this is the airport, however, I would not make this an airport to connect through. My wife and I would more then likely go through Madrid as it would be a lot easier. This airport might be a challenge for someone with mobility issues.