ILS Critical Area

B767Driver

B767Driver

New Member
There must be a brand new CFI here somewhere...Here's my question....when the weather is less than 800 & 2, are you required to automatically hold short of the ILS critical area...or only when directed by ATC?

My understanding is that you automatically hold short...another pilot is telling me that you only hold short when directed by ATC. Interestingly enough, the AIM is too vague to declare a winner in this contest. I cannot find any other regulatory guidance on this issue

Does anyone have a definitive answer?
 
After reading the AIM I would say it is clear.
1-1-9-k2a1:
".....vehicles and aircraft are not authorized in or over the critical area when an arriving aircraft is between the ILS FAF and the apt."
".....when the ceiling is less than 200 feet and/or the vis. is RVR 2000 feet or less, vehicle and aircraft operations in or over the are are not authorized when an arriving aircraft is inside the ILS MM."
1-1-9-k2a2:
".....vehicles and aircraft are not authorized in the area when an arriving aircraft is between the ILS FAF and the apt. unless the aircraft has reported the apt. in sight and is circling or side stepping to land on a rw other than the ILS rw."
1-1-9-k2b1:
At or above ceiling 800 feet and/or vis 2 miles......."no critical area protective action is provided under these conditions."

So to answer your question, I would say the answer is yes. When the clgs are below 800 ft. I would say you are required to hold short.

Additionally, I would query the tower and ask if we need to hold short of the critical area. A quick question could save you some heartache and a controller maybe asking you to take down a phone number.
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A quick question could save you some heartache and a controller maybe asking you to take down a phone number.
grin.gif


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I had a controller in Norfolk as me to take down a number once....

We had dinner the following weekend....
grin.gif
 
I, as a habit, hold short of the critical area. It's not that far from the normal VFR hold, and I do it so someone even practicing approaches doesn't get any anomalies. Not required, but that's just me. Normally, ATC will give "....taxi to RW 25, hold short at the ILS line." is what I've usually heard if that's what they want.
 
It works the same as a taxi clearance to cross a runway - if you are cleared to taxi without being told to hold short of the critical area, then you are clear to taxi through. The AOPA ASF courses address this issue.
 
From my understanding ATC will tell you to hold short of it if you are supposed to hold short of it. You need a clearance to taxi to the runway, so they are not going to clear you to the runway (which starts at the hold short lines) if you are realy only cleared to the ILS critical area. Furthermore, how are you supposed to know that there is an a/c between the FAF and the airport if ATC dosn't tell you so. Not that I would taxi into it without at least asking though.
 
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From my understanding ATC will tell you to hold short of it if you are supposed to hold short of it. You need a clearance to taxi to the runway, so they are not going to clear you to the runway (which starts at the hold short lines) if you are realy only cleared to the ILS critical area. Furthermore, how are you supposed to know that there is an a/c between the FAF and the airport if ATC dosn't tell you so. Not that I would taxi into it without at least asking though.

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Correct, ATC will tell you what they want.
 
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How about at a non-towered field? The airport I instructed at had one.

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AIM 1-1-9 states that ILS critical areas are not protected at uncontrolled airports. This is a poorly worded section of the AIM...I believe the intent of the ILS critical area is to hold short of it when wx is below 800/2...however...I cannot find any guidance that mandates it unless directed by ATC. Best practices would dictate that you would hold short of the crit area...but doesn't look like you have to.

I think I'm going to lose my bet...I don't see where it is written that it's mandatory to hold short unless directed by an ATC facility.
 
Well, lets think about this. If it is below 800/2, you won't be able to see if there is an aircraft on final, so you won't know if it is safe to take the runway for takeoff. That is why we have CVTs. I find it hard to believe that approach would clear an aircraft for an ILS approach or any other approach for that matter, while another aircrft is cleared for departure. So the way I would interpret that is, if I do not have a clearance, or my CVT has expired, I would keep clear of the ILS critical area while taxiing around the airport. Otherwise I'd just take the runway. No need to hold short of anything.
 
There is language that tells us we must hold short if it is less than 800 and 2. The 7110.65 also metions that ATC should tell you to hold short. So...do not let them boss you around if you do not. They have joint responisibility.
 
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There is language that tells us we must hold short if it is less than 800 and 2. The 7110.65 also metions that ATC should tell you to hold short. So...do not let them boss you around if you do not. They have joint responisibility.

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DE727UPS,

Would you direct me where to find that language. Thanks.
 
FAA Order 7110.65 - Air Traffic Control - Paragraph 3-84

http://www.faa.gov/avr/afs/hbat/hbat9412.txt

A. Air Traffic Operations.

(1) Flight Procedures. The current edition of FAA Order
7110.65, "Air Traffic Control," paragraph 3-84, specifies air
traffic procedures for ILS critical area protection. In general,
the runway's appropriate CAT I, II, or III critical area is
restricted for all aircraft and vehicle operation whenever any of
the following conditions exist:

1) the reported ceiling is less than 800 feet
2) the visibility is less than 2 miles
3) an aircraft on the ILS approach is inside the outer
marker (OM) or fix used in lieu of the OM, except a preceding
aircraft approaching the same runway or another runway may pass
over or through the area while landing, taking off, or exiting
the runway.

(2) Ground Procedures. In addition, vehicles or aircraft
operations are not authorized in or over the area when an
arriving aircraft is inside the middle marker when conditions are
less than 200 feet and/or RVR 2000. The entire longitudinal axis
of the preceding aircraft must be clear of the CAT III critical
area (approximately 250 feet either side of centerline) before
the aircraft on the ILS approach, or an autoland approach,
reaches the middle marker (MM) or 200 feet above ground level
(AGL).

B. Limitations. While it may appear to be desirable to
completely restrict critical areas from all surface traffic, this
is not generally feasible since normal access to and from the
runway, terminal areas, and ramp may necessitate movement through
these areas. In general, the localizer critical area for CAT
II/III airports/runways extends along the runway approximately
250 feet on either side of centerline. CAT II/III critical area
dimensions are based on the assumption that the entire
longitudinal axis of the aircraft/vehicle is clear of this area.
Aside from necessary ancillary components, ILS critical areas
would need to be established in order to conduct operations in
CAT II/III weather conditions at an ILS airport/runway currently
limited to CAT I operations.
 
I found it once in the 7110.65 when doing some research on this subject. I'm in Mexico right now in an internet cafe but I'll see if I can find it for you later.
 
From the 7110.65

3-7-5. PRECISION APPROACH CRITICAL AREA

a. ILS critical area dimensions are described in FAAO 6750.16, Siting Criteria for Instrument Landing Systems. Aircraft and vehicle access to the ILS/MLS critical area must be controlled to ensure the integrity of ILS/MLS course signals whenever conditions are less than reported ceiling 800 feet or visibility less than 2 miles. Do not authorize vehicles/aircraft to operate in or over the critical area, except as specified in subpara a1, whenever an arriving aircraft is inside the ILS outer marker (OM) or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway.

PHRASEOLOGY-
HOLD SHORT OF (runway) ILS/MLS CRITICAL AREA.

1. LOCALIZER CRITICAL AREA

(a) Do not authorize vehicle or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM when conditions are less than reported ceiling 800 feet or visibility less than
2 miles, except:

(1) A preceding arriving aircraft on the same or another runway that passes over or through the area while landing or exiting the runway.

(2) A preceding departing aircraft or missed approach on the same or another runway that passes through or over the area.

(b) In addition to subpara a1(a), do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the middle marker when conditions are less than reported ceiling 200 feet or RVR 2,000 feet.

2. GLIDESLOPE CRITICAL AREA. Do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway when conditions are less than reported ceiling 800 feet or visibility less than 2 miles.

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.

PHRASEOLOGY-
ILS/MLS CRITICAL AREA NOT PROTECTED.
 
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