Again some one might proof me wrong. My understanding is the in the US some pilots developed the habit of leaving the undercarriage selector in the up position all the time and let the automatic do the work. Well you guessed it, the automatic sometimes fails and the 'idiot' lands with wheels up. With the other problems already mentioned a SB or AD was issued to have the automatic removed or disabled and placarded. There should be something in the AFM regarding what was done.