Re: 757 Autoland

From:         turbulence1 <chartr1@hermes.univ-poitiers.fr>
Organization: C.R.I.U.P., Universite de Poitiers (FRANCE)
Date:         10 Dec 95 02:51:44 
References:   1
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Dear Hans. What i'can tell you about autoland, is that in some circumstances,
it is safer to let the autopilot land the aircraft! As you probably know there
is 3 different category in instrument approach. They are corresponding to
different weather conditions. Cat II and Cat III approach are executed when
vertical and horizontal visibility are very low (decision height in Cat II is
100 ft ). Because of this poor weather conditions it is safer to let the
autopilot follow the ILS indications. In fact such precision approach can be
done only under certain conditions : Autopilot must be certified for autoland,
crew must be cerfied for such operations ( at least one pilot/cockpit in some
airlines), ILS must  be precise enough and runway must have special approach
lighting ramp.
When in operations you never land in zero/zero that means you dont even know if
you are on the ruway after landing! Country and airlines are giving there own
"minima", in France (my country!) the lowest minima are, in Cat III approach,
about 50 meters of horizontal visibility and 0 meters of vertical visibility.
Considering you own experience, pilot got to keep experience in autolanding
even if the weather is beautiful! I hope this answer to some of your questions.