Autoland- "fault protection"
I was listening to EGGW approach a couple of nights back and the pilot of an aircraft that had just become localiser established on 08 informed the controller that he wished to carry out a "practice autoland". The controller acknowledged the request and went on to inform the pilot that there was "no fault protection".
When he was handed over to the tower the tower controller repeated the "fault protection" statement.
Can anyone shed some light on what "fault protection" means in this context?
Kind Regards,
???pax