Re: Korean Air 801 crashed on approach to Guam

Date:         08 Aug 97 05:41:21 
From:         Phil Wood <woodp@netgate.net>
Organization: AeroMarketing Associates (http://www.aeromarketing.com)
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jf mezei wrote:

> Could someone put this missing glide slope in perspective ?

The folks at Jeppeson were kind enough to post a copy of the Agana ILS
6L approach at http://www.jeppesen.com/guam.html.

If radar is out, it would be up to the pilot to navigate to either
HAMAL, FLAKE or ZEEKE at 2,600 ft and then navigate until lining up on
the IGUM localizer. Turn inbound and descend to 2,000 ft.  If radar is
up, ATC would vector you to a point somewhere between FLAKE and GUQQY.

If the GS had been functional, the pilot would have received vertical
guidance information about 5 miles from the airport and followed a 3
degree slope until 200 feet above ground - If he sees the airport, he
lands, if not, he goes around and may try again.

With the GS out, the approach reverts to a localizer approach and the
pilot uses a series of vertical steps to descend to the airport.
According to this approach plate, he drops from 2,000 to 1,440 ft after
crossing 1.6 miles from the UNZ VOR and then to 560 feet (304 above the
ground) after crossing the UNZ VOR.

Note that the LOC requires a little more effort to descend and level off
and descend and level off, while the ILS is a nice continuous descent.
Also note that you can descend to 200 ft above the ground on the ILS
(304 on the LOC) so in low clouds you have a better chance to see the
runway and land on an ILS.

A localizer requires a little more effort than an ILS, but it certainly
wouldn't have overwhelmed this experienced crew.

--
     Phil Wood                                  woodp@netgate.net
                                        73717.3453@compuserve.com
                                    Philip.Wood@sv.sc.philips.com
     <a href = "http://www.aeromarketing.com/woodp">Phil Wood</a>