Hi Centaurus,
Yes we do that on the 767 too. Yes its to guard against the aircraft suddenly doing a dirty dart due to some type of aircraft or ground aid failure..more likely when doing a practice autoland when Low Vis Procedures are not in force.
There have been cases of aircraft suddenly doing a dirty dart stage left/right and I guess this gives you the extra nanosecond required to correct the problem...we actually hold the relevant controls as if flying the aircraft...only lightly of course.
Mind you in every failure scenario I can remember in the sim the aircraft continues on it's stately way via the IRSs....can remember in initial AWOPs training not noticing a complete ILS transmitter failure below 1000 radio...the aircraft continued on as if nothing had failed and landed itself normally
Did you do Cat3b stuff in the 737s you flew in Europe?
We do 3b no decision...ie 75m vis 0 cloud base...taxiing is the harder bit
I must say it does make sense to me to have the PF's hands on the controls during an autoland....for starters you need to have your thumb poised over the GA button if someone strays into the protected area and bends the localiser signal. That happened to me in the sim...scares the crap outa you when you see the HIALS out the left window at 50R.
Chuck.