ILS Unusable

NealRomeoGolf

NealRomeoGolf

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What does this note mean exactly “ILS unusable” on the ILS Rwy 12 to KBFF? Does that mean at FERPO the guidance of the ILS is not usable? At that point you have visual or you go missed?


1EEE5D95-BF5F-4201-BC2B-4D4092B2532C.jpeg
 
Interesting question. Some quick math shows you would get to DA before that fix and would have to be visual or go missed by then anyway, unless you're way above the glideslope.
 
My guess is it’s a heads up not to react to needle movement after you’ve transitioned to a visual after FERPO. Which could potentially lead to a long or hard landing.
 
dmspilot said:
Interesting question. Some quick math shows you would get to DA before that fix and would have to be visual or go missed by then anyway, unless you're way above the glideslope.
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I figured this would be moot because it is only 0.3 nm from the threshold. Plus that is the missed approach point anyway, right?
 
Boone said:
My guess is it’s a heads up not to react to needle movement after you’ve transitioned to a visual after FERPO. Which could potentially lead to a long or hard landing.
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True. The 121 carrier I work for trained us to follow the ILS in low visibility basically until it was time to flare (and this is for Cat I, we do not have Cat II authorization).
 
NealRomeoGolf said:
I figured this would be moot because it is only 0.3 nm from the threshold. Plus that is the missed approach point anyway, right?
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MAP on an ILS is DA.

edit: DA on the glideslope.
 
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dmspilot said:
True. The 121 carrier I work for trained us to follow the ILS in low visibility basically until it was time to flare (and this is for Cat I, we do not have Cat II authorization).
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I keep it in my scan usually until the 50’ call, so if there was a big deviation it would get my notice. In that case I’d appreciate that note.
 
NealRomeoGolf said:
What does this note mean exactly “ILS unusable” on the ILS Rwy 12 to KBFF? Does that mean at FERPO the guidance of the ILS is not usable? At that point you have visual or you go missed?


View attachment 89028
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Maybe they are saying you shouldn’t be using the ‘needles’ to continue below DA to 100 feet above touchdown zone elevation as provided for in FAR 91.175 (c) (3) (i)
 
dmspilot said:
MAP on an ILS is DA.
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Agghhh!!! No it is not. DA ‘establishes’ the MAP. It is a ‘point,’ a geographic point. It is where the Glideslope, at DA, is. If you must execute a Missed Approach ‘early’ for some reason, say ATC says execute missed approach, or you have some problem with the plane that you can’t land, or maybe you’re just way behind and the needles are going nuts, to say you must continuing descending to DA before ‘missing’ is absurd.
 
luvflyin said:
Agghhh!!! No it is not. DA ‘establishes’ the MAP. It is a ‘point,’ a geographic point. It is where the Glideslope, at DA, is.
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First, yes, I know it is on the glideslope. That wasn't the point. Read the post I was replying to and don't take my comment out of context. I wrote what I did because OP thought FERPO was the MAP on the ILS.

luvflyin said:
If you must execute a Missed Approach ‘early’ ... to say you must continuing descending to DA before ‘missing’ is absurd.
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I didn't say that. I didn't say anything close to that. And I didn't imply that, nor can I figure out why you think I did.

Going missed early is a completely different issue and it's not even related to what we were talking about. It's also not even related to your own point about the ILS MAP being not "DA" but "DA on the glideslope".

What a strange response.
 
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And since it said ILS, neither the LOC or GS is to be trusted beyond FERPO.
 
Isn't the ILS equipment usually at the other end of the runway? I notice there is an altitude difference between the runway ends. Possibly there is a crown in the runway or other obstruction that makes the signal unreliable?
 
midlifeflyer said:
Actually, I have found that non-lawyers try to find hidden meanings in simple sentences far more than lawyers :D
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It's just PTSD from having lawyers for friends. Ha!

I am friends with a local judge here and he likes to twist every sentence uttered.....mostly just to annoy people.
 
bflynn said:
Isn't the ILS equipment usually at the other end of the runway? I notice there is an altitude difference between the runway ends. Possibly there is a crown in the runway or other obstruction that makes the signal unreliable?
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The localizer for a front course signal is at the far end of the runway. The Glide Slope is usually just off to the side about 1000' down.
 
dmspilot said:
MAP on an ILS is DA.

edit: DA on the glideslope.
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Which here seems to be FERPO anyway

bflynn said:
Isn't the ILS equipment usually at the other end of the runway? I notice there is an altitude difference between the runway ends. Possibly there is a crown in the runway or other obstruction that makes the signal unreliable?
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Hence the 1.8 DME.

As far as reliability, there are lots of reasons. If you ever fly the ILS into KBUR, you'll see just how quickly things can get unreliable.
 
dmspilot said:
First, yes, I know it is on the glideslope. That wasn't the point. Read the post I was replying to and don't take my comment out of context. I wrote what I did because OP thought FERPO was the MAP on the ILS.



I didn't say that. I didn't say anything close to that. And I didn't imply that, nor can I figure out why you think I did.

Going missed early is a completely different issue and it's not even related to what we were talking about. It's also not even related to your own point about the ILS MAP being not "DA" but "DA on the glideslope".

What a strange response.
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“MAP on an ILS is DA” is like finger nails screeching on a chalkboard to me. My response was directly to your post #6. @Boone ’s post #3 was spot on about what the note is about and I think your post #5 continued the point very well. Please don’t take it personally that I went off on my rant replying to you. I would have done it to any ‘MAP on an ILS is DA’ post regardless of what original post started the thread. I could’ve done it better. My lesson learned, https://www.dailyedge.ie/drunk-text-prevention-993788-Jul2013/
 
luvflyin said:
Lol. There it is, duh. I went straight to looking for where the glideslope intersected the runway.
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1.83 is the location of the LOC MAP.

Funny, it says "MAP: ILS: DA". You better write to the FAA and complain they don't know where their own MAP is.
 
flyingron said:
The localizer for a front course signal is at the far end of the runway. The Glide Slope is usually just off to the side about 1000' down.
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KBUR is an exception on the LOC antenna location. Don’t know whether there are others.
 
In the unlikely event you find yourself in an emergency situation, with low fuel and the area is socked in, you wouldn't want to pick this ILS to fly to the ground.
 
aterpster said:
KBUR is an exception on the LOC antenna location. Don’t know whether there are others.
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Just calling @N1120A 's attention to this in case you aren't following this thread anymore. Reference your post #20. Don't know if you knew the reason or not.
 
aterpster said:
KBUR is an exception on the LOC antenna location. Don’t know whether there are others.
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luvflyin said:
Just calling @N1120A 's attention to this in case you aren't following this thread anymore. Reference your post #20. Don't know if you knew the reason or not.
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Interesting. That totally explains why it gets so unreliable about a mile out.

flyingron said:
Where is it at KBUR? It's hard to see in the Google shot.
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Never knew this, but zoom in. It is at the approach end of Runway 8

2560px-KBUR.jpg
 
N1120A said:
Interesting. That totally explains why it gets so unreliable about a mile out.



Never knew this, but zoom in. It is at the approach end of Runway 8

2560px-KBUR.jpg
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I don't think it's showing in that pic. Pretty sure it is across the street. The North/South running street at the left of the photo is Vineland Ave. About 600 feet to the other side.
 
luvflyin said:
I don't think it's showing in that pic. Pretty sure it is across the street. The North/South running street at the left of the photo is Vineland Ave. About 600 feet to the other side.
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You can pretty easily see the LOC antenna there.
 
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