Re: 757 Autoland

From: (Gary Gershzohn)
Organization: MDC
Date:         17 Dec 95 02:11:48 
References:   1
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Autoland systems generally include the following capabilities: ability to
track the localizer and glide slope; align with the runway centerline
close to the runway; flare (pitch up and power reduction); and lower the
nose after touchdown. There is considerable redundancy with typically two
or three systems talking to each other along the approach. The MD-11 uses
two autoland systems for approach.

Regarding landing minimums, these systems are used for Category 3
approaches. There are three types at Cat 3 approaches depending on the
visibility certified for landing operation: Cat 3a 1200ft  Cat 3b 700 ft
Cat 3c 0 ft. Distances are slightily different in Europe with metric
numbers. There is no ceiling requirement. The requirements for making an
approach to any of these minimums depend on on board equipment, airport
facilities, crew training, and crew certification. In other words, each
one of these has regulatory requirements that must be met at the time the
approach is made. If one is not met, the an approach to higher minimums
would have to be used.

In article <airliners.1995.1889@ohare.Chicago.COM>, (Hans Yao) wrote:

> I was recently aboard an USAir 757 tht executed an autoland at Charlotte,
> nice smooth approach and touchdown was smooth, though solid.
> I queried the flight crew after the flight (just wanted to see the flight
> deck, didnt know Id stumble onto such an interesting topic.)  He said
> that that landing was a routine test of the system, certified for
> approaches to 600 feet visibility.  Is there anyone out there that would
> care to post or mail me more information about the various autoland
> systems, how they work, what the specifications are, if they are legal
> for zero-zero?  I thought it was pretty interesting, the plane being able
> to do that all on its own.
> Anyone with any thoughts, remarks, or previously posted information on
> the topic?
> Hans