In the incident examined in this video the pilots experienced an unreliable airspeed indication due to pitot tube blockage in an A330. They followed the abnormal checklist for unreliable airspeed which instructed them to switch off all three ADRs.
In the video it is mentioned that with the ADRs switched off that they had to use gravity extension of the landing gear, which caused one of the gear doors to briefly strike the runway. Also it inhibits nose wheel steering requiring a tug to get the plane off the runway.
I can’t figure out why the lack of ADRs would affect these two systems. I know that gear extension would be inhibited above a certain airspeed, but it seems that switching off the ADRs should override this. Why would it require alternate gear extension? And why would nose wheel steering be affected on the ground?