addressed this subject before, and is worth reading. The short version: it does not mean that the plane flies or lands itself.
Avianca flight 52 crash, and you can have a combination of pilot error/training with a technical issue (e.g. American Airlines flight 587). Obviously this isn't the same sort of crash as those two, but I guess we'll have to wait for the investigation to find out what happened. Possibly not even then.
(yes, I've watched too much Air Crash Investigation...)
I am very sorry for the loss of life, though relieved that it wasn't even worse. The early images looked quite scary.