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ILS Critical Area Hold Line

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flyboyike

Urban Legend/Rural Myth
Joined
Apr 30, 2006
Posts
1,852
I was recently asked if there were any weather parameters associated with an ILS Critical Area hold line going into effect. IOW, the person implied that the hold line went into effect when the weather went below certain minimums. The person never told me what those minimums are and I was under the impression that it went into effect when ATC said it was in effect. I couldn't find anything different either in FARs or AIM. Anyone know what these minimums are (if they exist)?
 
Someone will correct me really soon but I think it goes into effect when weather is below 800 & 2.

*Disclaimer.... I am on furlough and have forgotten almost everything I have learned about flying.
 
800 and 2, when in doubt ask

Absolutely I agree about asking. Can you point me to where the 800 and 2 is in the regs? I'm not doubting you, I just want to know in case I have to point someone else to the reg in question.
 
I was always under the impression that it was an ATC function....

As was I. Operationally, I don't see why I should care what the minimums are, if they tell me to hold short of the ILS hold line, I'll do it, even if it's clear and a million.
 
AIM 1-1-9

http://www.faa.gov/airports_airtraffic/air_traffic/publications/ATpubs/AIM/Chap1/aim0101.html#1-1-22

k. ILS Course Distortion

1. All pilots should be aware that disturbances to ILS localizer and glide slope courses may occur when surface vehicles or aircraft are operated near the localizer or glide slope antennas. Most ILS installations are subject to signal interference by either surface vehicles, aircraft or both. ILS CRITICAL AREAS are established near each localizer and glide slope antenna.
2. ATC issues control instructions to avoid interfering operations within ILS critical areas at controlled airports during the hours the Airport Traffic Control Tower (ATCT) is in operation as follows:
(a) Weather Conditions. Less than ceiling 800 feet and/or visibility 2 miles.
(1) Localizer Critical Area. Except for aircraft that land, exit a runway, depart or miss approach, vehicles and aircraft are not authorized in or over the critical area when an arriving aircraft is between the ILS final approach fix and the airport. Additionally, when the ceiling is less than 200 feet and/or the visibility is RVR 2,000 or less, vehicle and aircraft operations in or over the area are not authorized when an arriving aircraft is inside the ILS MM.
(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.

So ATC will tell you if they need you to hold short if the tower is open...
 
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Whoa Whoa Whoa.....what is this sharing of useful information on Flightinfo all about????

Moderators, delete this thread immediately!!!!!!!
 
Andy and Veneratio,

Good stuff, thanks for the info.

Take a look at ATL's diagram.

http://upload.wikimedia.org/wikipedia/commons/d/dc/ATL_-_FAA_airport_diagram.png

You land on 8L like we were today doing CAT 2 approaches. you are told to join Bravo westbound to Victor. Along the way there is an ILS Hold Short sign. Do you keep going???? There's one at B1 and one at B2.

According to Veneratio's article, it looks like as a landing aircraft, you are not required to hold???
 
AIM 1-1-9

http://www.faa.gov/airports_airtraffic/air_traffic/publications/ATpubs/AIM/Chap1/aim0101.html#1-1-22

k. ILS Course Distortion

1. All pilots should be aware that disturbances to ILS localizer and glide slope courses may occur when surface vehicles or aircraft are operated near the localizer or glide slope antennas. Most ILS installations are subject to signal interference by either surface vehicles, aircraft or both. ILS CRITICAL AREAS are established near each localizer and glide slope antenna.
2. ATC issues control instructions to avoid interfering operations within ILS critical areas at controlled airports during the hours the Airport Traffic Control Tower (ATCT) is in operation as follows:
(a) Weather Conditions. Less than ceiling 800 feet and/or visibility 2 miles.
(1) Localizer Critical Area. Except for aircraft that land, exit a runway, depart or miss approach, vehicles and aircraft are not authorized in or over the critical area when an arriving aircraft is between the ILS final approach fix and the airport. Additionally, when the ceiling is less than 200 feet and/or the visibility is RVR 2,000 or less, vehicle and aircraft operations in or over the area are not authorized when an arriving aircraft is inside the ILS MM.
(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.

So ATC will tell you if they need you to hold short if the tower is open...

Thank you muchly for that. So, it sounds to me as though it's still up to ATC to tell you to hold short of that dang line, thus it's an ATC function either way, since there is no regulatory requirement to hold short thereof, unless told by ATC. Phew.
 
Andy and Veneratio,

Good stuff, thanks for the info.

Take a look at ATL's diagram.

http://upload.wikimedia.org/wikipedia/commons/d/dc/ATL_-_FAA_airport_diagram.png

You land on 8L like we were today doing CAT 2 approaches. you are told to join Bravo westbound to Victor. Along the way there is an ILS Hold Short sign. Do you keep going???? There's one at B1 and one at B2.

According to Veneratio's article, it looks like as a landing aircraft, you are not required to hold???

I think that if they need you to hold than they will tell you.
 
Hold short when TOLD to hold short by ATC..Or as usually the case in LGA, the ATIS may broadcast to hold short... (but it's been awhile since I've been to LGA)

I've always been frustrated when a Captain holds short when nothing was said from ATC..Especially on a clear day.... Then again, it is just safer to hold short and ask questions later..So no harm no foul..
 
Regardless of the weather, if ATC says "hold short," then by golly I reckon you hold short. Thus speaketh Captain Obvious.

< 800 or 2, and not told to "hold short," hold short anyway. ATC will tell you to cross it. If ATC and/or another pilot and/or the right seat captain FO gets pissy about that, shrug and smile.
 
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I think that if they need you to hold than they will tell you.


If the ATIS is calling wx at or below 800/2 listen to ground for bit and you'll generally know ahead of time what they want you to do. If you're not sure, ask. Many of the larger airports have towers that have an obscured view of the end of the runway with low ceiling/vis. and may not see your position before it's a problem. ATL rwy 28/10 comes to mind (granted they have ground radar).
 
Also, part of the criteria for doing Cat II's is that the controllers ensure that all of the Cat II critical areas are protected....again it's on them.
 
Also, part of the criteria for doing Cat II's is that the controllers ensure that all of the Cat II critical areas are protected....again it's on them.


It is all on ATC, you do not have to ask, you are only required to hold short when instructed by ATC. If ATC says nothing then continue on. Do not waste your breathe asking ATC. Save the radio space. The 800-2 is a guide for when ATC may issue A hold short of the critical area. Some of you need a refresher course, its all ball bearings and PFM......
 
When the wx is 800/2 or less, hold short. Its better to err on the side of caution. Its like crossing a runway, you want to be sure you have clearance before you cross.

That's my 2 cents...
 
Andy and Veneratio,

Good stuff, thanks for the info.

Take a look at ATL's diagram.

http://upload.wikimedia.org/wikipedia/commons/d/dc/ATL_-_FAA_airport_diagram.png

You land on 8L like we were today doing CAT 2 approaches. you are told to join Bravo westbound to Victor. Along the way there is an ILS Hold Short sign. Do you keep going???? There's one at B1 and one at B2.

According to Veneratio's article, it looks like as a landing aircraft, you are not required to hold???

I think (not 100% sure) the ILS hold line for 8L is the one on taxiway Alpha. The one on Bravo is in the very rare event they are using 8R. One thing that is a little unusual, is there are two ILS Hold lines on Bravo. Never seen that before and have no idea why there would be two. Any ideas?
 

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