B757 autoland questions
Could somebody help me with a couple of issues I have about the B752 autoland system?
1. Crosswind autolandings.
According to a BA 757 manual, the "runway align" submode is used to "reduce crab angle in compensating for a crosswind condition during...an automatic landing."
It then says that on mode engagement, a slip will be initiated when the crab angle exceeds 5 degrees, removing the slip when ROLLOUT is engaged, and the crab angle remains.
This last bit seems to contradict what was said previous to that regarding removing the crab angle.
So if anyone could tell me what in reality the 757 actually does in a cross wind autoland, I'd be very grateful. Does the aircraft align itself with the runway before touchdown and if not, does it align after touchdown or does the pilot need to kick it straight for roll out?
Also, if the aircraft is to touch down non-aligned, what is the purpose of the slip? Is it to reduce the crab angle to an angle less likely to tear off the gear on touchdown?
2. If the aircraft needs to be manually aligned with the runway, is this the reason the BA manual rules out Cat3C landings? Or is it because a 0 RVR would make finding the gate a tad difficult?
Thanks in advance for any answers. I may yet pass my JAR exams!