This is a video of the aircraft just prior to the accident. Is it any wonder why they ended up on the grass?
http://www.facebook.com/photo.php?v=10151685339989524
This part of Indonesia is cowboy country. At Sentani near Jayapura you often see aircraft of all sizes turn on to final at a heights of less than 500 ft including Boeing 737 freighters, as they weave their way in and around cloud in marginal VMC conditions. G-I-L-A !! (CRAZY !!)