ILS critical area when the tower is closed?

Steven P. McNicoll wrote:

wrote in message news:rbwgf.4658$pF.1342@fed1read04...

91.129 requires that the ILS be followed at a Class D airport. It does
not require that the full procedure be flown. If cleared for a visual to
an ILS runway, for example, the 121 crew must have the ILS tuned and
identified and use it once lined up with the runway.



The requirement in FAR 91.129 is that a large or turbine-powered airplane
approaching to land on a runway served by an ILS must fly at an altitude at
or above the glide slope. The claim by Newps was; "The airlines will always
fly the ILS if there is one up and running. They are required to."


I didn't infer that he meant the full procedure. But, perhaps he did.
Newps?

Steven P. McNicoll wrote:

wrote in message news:l6wgf.4657$pF.1345@fed1read04...

Did someone in this thread suggest there was any kind of priority issue in
the use of approach couplers or autoland systems?



Yes.


Help me with a reference if you can.

Steven P. McNicoll wrote:

wrote in message news:Sjwgf.4659$pF.917@fed1read04...

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.



You're more than a bit out of context. There is no tower to advise as we're
talking about ILS critical areas when the tower is closed.


And, the context of ILS critical areas when a tower is closed would
logically include a discussion of the similarities to an airport that
has an ILS but no control tower.

Steven P. McNicoll wrote:

"Jose" wrote in message
. ..

Sure it is. The fuel vendor is a machine. It doesn't sleep, and never
leaves the airport.



The fuel vendor is typically a person.


You have to get out more, Steve.

wrote in message news:Sjwgf.4659$pF.917@fed1read04...
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.

I don't think I am.

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.

If you're reading that to mean that unless the advisory is issued the
critical areas are protected you're not only out of context you don't know
controllers or how the ATC system works.

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.

Controllers are not going to protect the critical areas (ie, tie up useable
taxiway space and slow down traffic) unless they have a specific foreseeable
requirement to do so (ie, weather below 800-2). They certainly aren't going
to do it on the off-chance some air carrier *might* advise it is doing a
coupled or autoland approach.

If the weather is above 800-2 (ie, good) and ATC is not protecting the
critical areas (which they will not be), then they are required to issue the
advisory when the aircraft tells them it will be making a "coupled" or
"autoland" approach. If they're not issuing the advisory under those
conditions it's because they forgot.

I can't help what crews may or may not be trained to do or expect. If
they're taught to assume that absent an advisory the ILS critical areas are
protected when the weather is above 800-2 they're being taught to make an
unrealistic and potentially dangerous assumption.

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.

There hasn't been any requirement to protect the critical areas for coupled
or autoland approaches or any other reason when the weather was above 800-2
for the last 27 years or more.

If there ever was (which I doubt) it was very short-lived. Apart from the
sheer physical impracticality of such a requirement, I seriously doubt even
the FAA would put in place a requirement that would delay or otherwise screw
other users of the system in order for some air carrier to fill one of their
internal proficiency/equipment check squares.

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.

Assuming the tower is protecting the ILS critical areas when the weather is
above 800-2 simply because no advisory is issued is an unrealistic and
potentially dangerous assumption on the part of the aircrew. The smarter,
safer, and more likely assumption would be the tower forgot to issue the
advisory.

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.

As you're the one who brought the .65 (ie, controllers, their duty
requirements, and thus a situation where the tower is open) into the thread
it's only fair you should be the one to de-creep it.

And when the tower *is* open that aircrew would be equally savvy not to
assume the critical areas are protected simply because ATC forgot to issue
an advisory.

wrote:


I didn't infer that he meant the full procedure. But, perhaps he did.
Newps?

No of course not. Only an idiot would infer that. If there is an
operating ILS to the runway they are landing on they must use them for
that time they are on final. They can still turn final where ever they
want, although as I said before they will almost always turn at the
marker if you let them.

wrote in message news:CYBgf.4677$pF.224@fed1read04...
Steven P. McNicoll wrote:

wrote in message news:Sjwgf.4659$pF.917@fed1read04...

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.


You're more than a bit out of context. There is no tower to advise as
we're talking about ILS critical areas when the tower is closed.

And, the context of ILS critical areas when a tower is closed would
logically include a discussion of the similarities to an airport that has
an ILS but no control tower.


Okay. One of the similarities between airports that have an ILS but no
control tower and airports that have an ILS and a closed control tower is
that there is no tower to advise of an autoland or a non-autoland coupled
approach and no tower to protect the ILS critical area.

Steven P. McNicoll wrote:
"Gerald Sylvester" wrote in message
. net...

correct but there is a need to do an autoland. It is not
*required* since the weather is good enough but the
need is still there.
Don't be silly. There's clearly no need to do an autoland in good weather.

You see the reasons it is required to do
autolandings in good weather (not to land the plane but for currency)
and you still can't admit you are wrong. There is a need to do
autolandings but it isn't required to safely land the plane for
that particular approach. It is simply for currency and when
the need arrises.

I had you killfiled for a while and now I gotta admit you really
provide some good entertainment. So are you the debate club captain
in the high school you attend?

Gerald

"Gerald Sylvester" wrote in message
. com...

You see the reasons it is required to do
autolandings in good weather (not to land the plane but for currency)
and you still can't admit you are wrong.


I have no problem admitting when I'm wrong, but I certainly am not going to
say I'm wrong when I'm right.

KP wrote:

As you're the one who brought the .65 (ie, controllers, their duty
requirements, and thus a situation where the tower is open) into the thread
it's only fair you should be the one to de-creep it.

No, I brought in the .65 language after someone else had quoted the
alert language contained in that order.

And when the tower *is* open that aircrew would be equally savvy not to
assume the critical areas are protected simply because ATC forgot to issue
an advisory.


Here is what AIM 1-9-9 k says about it and has said pretty much the same
thing for a long time. Note the phrase "to ensure that the ILS critical
areas are protected..." (during weather better than 800-2):

(2) Glide Slope Critical Area. Vehicles and aircraft are not authorized
in the area when an arriving aircraft is between the ILS final approach
fix and the airport unless the aircraft has reported the airport in
sight and is circling or side stepping to land on a runway other than
the ILS runway.

(b) Weather Conditions. At or above ceiling 800 feet and/or visibility 2
miles.

(1) No critical area protective action is provided under these conditions.

(2) A flight crew, under these conditions, should advise the tower that
it will conduct an AUTOLAND or COUPLED approach to ensure that the ILS
critical areas are protected when the aircraft is inside the ILS MM.

I guess the AIM tells pilots one thing and controllers tell controllers
another thing. That has been going on for a lot longer than 27 years.