Re: CSAT III Landing Control

From: (Ralph Ricks )
Organization: Netcom
Date:         25 Jan 96 00:55:05 
References:   1 2 3 4 5 6
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In <airliners.1996.84@ohare.Chicago.COM> (adrian
Reedy) writes:
>On 10 Jan 96 02:01:42 , (Brian A. Reynolds)
> Note that no CAT III approaches may be initiated with any required
>air or ground component inop.  A failure at any point requires a
>missed approach.  Also,  no autopilot disconnects at DH with a manual
>landing are permitted underr CAT III.  By definition, they are
>autoland only.

Hi Brian!  One minor point here:  a fail passive autoland just gives
the plane back to the pilot if there is a failure at any time.  A fail
operational autoland system continues the approach and landing if there
is a failure at a point low in the approach.  The light twins:  MD-80
and 737-3,4,500 are CAT IIIA fail passive.  The 757, 767, 747-400, 777,
MD-11 and L-1011 are all CAT IIIB fail op.  The DC-10 was fail op when
it worked.
> I'm not familiar with the CAT III approval for retrofitted 727s with
>the heads-up display.  I don't -think- they have autoland capability.

With that neat Flight Dynamics Heads Up Guidance Sytem, they don't need
autoland.  The pilot flies the plane to a CAT IIIA landing.

Actually, some of the latest 727-200 were CAT IIIA autoland equipped.
I believe some carriers are using it.

There is talk of doing CAT IIIB in the 737-3,4,500 using the
combination of the fail passive autoland and the HGS.

>As a CAT IIIc landing would require a fully controlled nose steering
>|mechanism, are there any commercial aircraft certified for this?
Early in the 757 career, BA did 1,000 instrumented autolands without a
single failure.  That helped qualify the BA 757 for CAT IIIC, but they
received IIB rating only.  There is just no guidance to get off the
runway once the plane has stopped.