Originally Posted by aCavalierInCoach
Probably an a.net topic but I thought one of you might be able to shed some light on this. On UA 205 IAD-SFO last night our pilot asked approach to relay to tower that we would be on "auto-land". Both approach and later the tower noted that "ILS critical areas are not protected".
I assume the former just means something along of the lines of that we landed on autopilot (which was close to perfect, by the way). What's the deal with 'critical areas' though? And why might a pilot choose to autoland? Thanks.
D
There are different levels of ILS approaches, each with an increasing precision which allow operation in lower minimums (worse visibility weather). The catagories are labelled Cat I, Cat II, and Cat III, and Cat III is further divided into Cat IIIa, IIIb, and IIIc. Cat IIIc is a full automated landing requiring no visibility.
I understand that to keep their certifications to use these precision approaches (as well as just keep their skills current), pilots need to have performed a certain number of these procedures with some recent period of time. Since real CatIIIc landings are rare, pilots practice on normal landings.