KP wrote:

Man, I hate to side with McNicholl but...

wrote in message news:cjlgf.4216$pF.687@fed1read04...

Steven P. McNicoll wrote:

wrote in message news:CX9gf.1261$pF.1153@fed1read04...


It's a problem during a coupled approach especially if the pilot is
planning to do an autoland.



It's not a problem if the weather is good.



Not so, Steve. It can cause control problems and certainly adversely
affect an autoland. That is why your handbook contains a caveat about
such approaches.

Approach couplers and autoland systems are weather independent.~


The only "caveat" in the .65 regarding coupled or autoland ILS approaches is
in 3-7-5b. This simply requires an advisory to aircraft of "ILS/MLS
CRITICAL AREA NOT PROTECTED" when the weather is at or above 800-2.

So, if the weather is good (or good enough) all the pilot executing a
coupled or autoland gets is a warning (ie, a reminder not to trust the
electrons too much). For all practical purposes the ILS critical areas are
not in play. Nobody gets held at the instrument hold lines. In other
words, it's not a problem if the weather is good.

You're a bit out of context. Here is the context:

b. Air carriers commonly conduct "coupled" or "autoland" operations to
satisfy maintenance, training, or reliability program requirements.
Promptly issue an advisory if the critical area will not be protected
when an arriving aircraft advises that a "coupled," "CATIII,"
"autoland," or similar type approach will be conducted and the weather
is reported ceiling of 800 feet or more, and the visibility is 2 miles
or more.

When the weather is good, the crew is required to advise the tower when
they intend to do an autoland or even a non-autoland coupled approach.
If the advisory you mentioned is NOT issued then the crew is trained to
expect that the tower is protecting the critical areas.

The language used to be stronger, in that ATC was required to protect
the critical areas when the crew made such an announcement in good
weather. Apparently, that was too burdensome.

Nonetheless, most of the time when the crew announces its intent to do
an autoland/coupled approach in good weather, the tower does not issue
that alert, thus the crew can expect the ILS to perform without
interference.

De-creeping the thread a bit: the thread is about an airport without a
tower or a closed tower. A savvy air carrier crew would give serious
pause to considering a good-weather autoland at such an airport.