Question about the localizer for the ILS system

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BlackManINC

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If the notam reports that the localizer/DME station is out of service on an ILS approach, can you still shoot the approach using the glide slope intercept or the straight in ILS approach or will the pilot have to use the circling minima approach on the instrument approach procedure chart?
 
How can you shoot the approach if the LOC is out? How do you know where you're going if you don't have lateral guidence?
 
DavidWhite said:
If you localizer is out you should use a different approach as you don't have lateral guidance
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This. Now if the glide slope was out, you could still shoot a localizer approach as long as it is authorized, which they usually are, with higher minimums as it's then a non precision approach.
 
No. Without localizer, GS is useless and likely turned off anyway.


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Is the localizer out or just the DME?
 
mscard88 said:
See post #4 above.
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Yeah I knew that, I just wanted to further clarify that a vor receiver can be used for the localizer, because in the FAR AIM, it doesn't actually say that an ILS receiver is required to shoot an approach at class B airports where you typically see ILS systems. It only says that, "for IFR operations, you need either a Vor or Tacan receiver".
 
Are you training for your instrument rating, or already instrument rated?
 
BlackManINC said:
If the notam reports that the localizer/DME station is out of service on an ILS approach, can you still shoot the approach using the glide slope intercept or the straight in ILS approach or will the pilot have to use the circling minima approach on the instrument approach procedure chart?
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CN893PUVAAAMNpE.jpg
 
BlackManINC said:
No, I'm actually a flight dispatcher. I just got offered a job and wanted to make sure I have all my ducks in order, if you know what I mean. ;)
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OK, well, you use the VOR to dial/select the LOC frequency. I think that's what you're asking?
 
BlackManINC said:
Yes, thanks.
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To be clear, the VOR receiver in the airplane and its associated instrument (a CDI) are the same receiver and instrument used to tune and capture a localizer signal.

A glideslope signal can be paired to a localizer or LDA. If the glideslope is inoperative, the localizer or LDA are still usable. If the localizer or LDA are inoperative, the entire approach is unusable.
 
Harold Rutila said:
To be clear, the VOR receiver in the airplane and its associated instrument (a CDI) are the same receiver and instrument used to tune and capture a localizer signal.

A glideslope signal can be paired to a localizer or LDA. If the glideslope is inoperative, the localizer or LDA are still usable. If the localizer or LDA are inoperative, the entire approach is unusable.
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Got it, so this means that I can't even use the circling approach minimum if the localizer is inoperative?
 
BlackManINC said:
Got it, so this means that I can't even use the circling approach minimum if the localizer is inoperative?
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Based on this comment, I get the feeling that you don't know what a circling approach is either. Circling minimums are used when you wish to shoot the instrument approach to one runway, but then land on another.

What I think you mean by 'circling approach' is a visual approach meaning you see the airport and then land without needing to use an instrument approach procedure. If there were no instrument approach procedures available to an aircraft and its installed equipment (not likely on an airplane owned by a company required to have a dispatcher in the age of GPS), then yes, the aircraft would need to execute a visual approach. That would need to happen with weather well above most circling mins.
 
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jordane93 said:
There's no way to navigate laterally so you can't even shoot the approach.
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Got it

NKTFlyer said:
Based on this comment, I get the feeling that you don't know what a circling approach is either. Circling minimums are used when you wish to shoot the approach to one runway, but then land on another.
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Certain things weren't exactly explained clearly in the dispatch course. The circling minimum was barely touched upon, only the basic definition as you explain here.
 
BlackManINC said:
Got it



Certain things weren't exactly explained clearly in the dispatch course. The circling minimum was barely touched upon, only the basic definition as you explain here.
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No judgment. Knowledge is power. Your aircrew may be less forgiving, especially if they don't catch the NOTAM before they get there.
 
I can see where this would be confusing. A bit of PoA advice, this can be a tough crew if they think you're asking a question that, to many pilots, is common knowledge. If you have more questions, def preface it with the fact that you're a non-pilot and a dispatcher. I think some of the initial responses will be much more informative and you won't have some of our more notorious members piling on with internet memes....

Asking is always good and there are quite a few aviators here who are very knowledgeable and willing to help.
 
A dispatcher should and has to know this. If weather is down at a destination airport, knowing what approaches are available at that airport, and what is NOTAM out and how that affects the capability of the crew to fly it has to be considered. Either that or that flight will go somewhere else and inconvenience the passengers, if the crew doesn't catch it.
 
You can't use a VOR receiver to navigate on a localizer. The modulation is DIFFERENT than the VOR. Most nav/coms provde both VOR and LOC tracking.
 
Harold Rutila said:
To be clear, the VOR receiver in the airplane and its associated instrument (a CDI) are the same receiver and instrument used to tune and capture a localizer signal.

A glideslope signal can be paired to a localizer or LDA. If the glideslope is inoperative, the localizer or LDA are still usable. If the localizer or LDA are inoperative, the entire approach is unusable.
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flyingron said:
You can't use a VOR receiver to navigate on a localizer. The modulation is DIFFERENT than the VOR. Most nav/coms provde both VOR and LOC tracking.
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You two seem to be contradicting each other royally. The way I understand it now is simple. If you want to shoot a non-precision localizer approach, a VOR receiver would do just fine since the LOC and VOR frequencies are within the same range. If you want to tune into the glide slope intercept to shoot a precision approach however, then you'll need an ILS or glideslope receiver. If the localizer is inoperative, the entire instrument approach procedure is unusable. If this is not correct, then why would the FAA say that you can use a VOR receiver at class B airports where most of their approaches are either RNAV or ILS?
 
Harold Rutila said:
To be clear, the VOR receiver in the airplane and its associated instrument (a CDI) are the same receiver and instrument used to tune and capture a localizer signal.
Click to expand...

flyingron said:
You can't use a VOR receiver to navigate on a localizer. The modulation is DIFFERENT than the VOR. Most nav/coms provde both VOR and LOC tracking.
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BlackManINC said:
You two seem to be contradicting each other royally.
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Well. They're both right. Harold is telling you what's its like flying most aircraft. Flyingiron is just being pedantic. And now someone will come along and correct me soon.
 
BlackManINC said:
You two seem to be contradicting each other royally. The way I understand it now is simple. If you want to shoot a non-precision localizer approach, a VOR receiver would do just fine since the LOC and VOR frequencies are within the same range. If you want to tune into the glide slope intercept to shoot a precision approach however, then you'll need an ILS or glideslope receiver. If the localizer is inoperative, the entire instrument approach procedure is unusable. If this is not correct, then why would the FAA say that you can use a VOR receiver at class B airports where most of their approaches are either RNAV or ILS?
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The receiver / display unit (CDI) in the aircraft is the same box. Yes ILS/LOC is in the same frequency range as the VOR. The Glideslope and Localizer are tuned on one freq. How the box interprets the LOC vs VOR is internal to the box and nothing different for the Pilot.

You are correct, if the LOC is out of service the entire approach is unusable. A glideslope may be out so the localizer can be used to higher minimums. A VOR approach is even less accurate and possibly even higher minimums.
 
mfisher said:
Correct.



I am not following your logic, sorry. :(
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The FAA basically says that I can shoot the non-precision localizer approach with a VOR receiver on Runway 21L at Detroit Metro Airport shown below. This of course is also based on everyones explanation here and elsewhere. And like I said, ALL of Detroit Metro Airports approaches are either "RNAV", "ILS" only, or "ILS or LOC" approach procedures like the one below.

1
 
BlackManINC said:
a VOR receiver would do just fine since the LOC and VOR frequencies are within the same range.
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The VOR receiver, LOC receiver, DME receiver, and glideslope receiver are all separate.

In most modern installations, a single control head tunes all of them seamlessly depending on the frequency tuned. i.e. if a VOR freq is tuned then the VOR receiver is tuned and used. If a LOC frequency is tuned then the LOC receiver is tuned as is the paired G/S receiver. In both cases the paired DME frequency is tuned in the DME receiver.

This is important because individual components can be inoperative while the others continue to work--both at the ground stations and in the aircraft.

Many approaches can be flown with some inoperative components but, in all cases, you will need the applicable lateral guidance and possibly more.

The FAA's Instrument Procedures Handbook is a good resource.
 
Larry in TN said:
The VOR receiver, LOC receiver, DME receiver, and glideslope receiver are all separate.

In most modern installations, a single control head tunes all of them seamlessly depending on the frequency tuned. i.e. if a VOR freq is tuned then the VOR receiver is tuned and used. If a LOC frequency is tuned then the LOC receiver is tuned as is the paired G/S receiver. In both cases the paired DME frequency is tuned in the DME receiver.

This is important because individual components can be inoperative while the others continue to work--both at the ground stations and in the aircraft.

Many approaches can be flown with some inoperative components but, in all cases, you will need the applicable lateral guidance and possibly more.
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I know they are separate receivers, but the way I understand it, is you can still shoot a localizer approach using a VOR receiver.........right? It makes sense based on what it says in the FAR AIM.
 
BlackManINC said:
I know they are separate receivers, but the way I understand it, is you can still shoot a localizer approach using a VOR receiver.........right? It makes sense based on what it says in the FAR AIM.
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I think Larry already explained it above.

The instrument is the CDI. You fly the needle on the CDI. You keep saying VOR and that is what is throwing everyone off. So to answer your question, no. Being pedantic, you don't shoot a LOC approach using a VOR receiver. They are two different technologies, and therefore it's impossible.
 
BillTIZ said:
The receiver / display unit (CDI) in the aircraft is the same box. Yes ILS/LOC is in the same frequency range as the VOR. The Glideslope and Localizer are tuned on one freq. How the box interprets the LOC vs VOR is internal to the box and nothing different for the Pilot.

You are correct, if the LOC is out of service the entire approach is unusable. A glideslope may be out so the localizer can be used to higher minimums. A VOR approach is even less accurate and possibly even higher minimums.
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mfisher said:
I think Larry already explained it above.

The instrument is the CDI. You fly the needle on the CDI. You keep saying VOR and that is what is throwing everyone off. So to answer your question, no. Being pedantic, you don't shoot a LOC approach using a VOR receiver. They are two different technologies, and therefore it's impossible.
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Ok, well that settles it then
 
The GlideSlope isn't anywhere near the LOC frequency. It's on a paired UHF channel.
 
You guys are making this more difficult than it needs to be. While the VOR/LOC/GS signals all use separate receivers, in practice they are all integrated into a single Nav radio and display on a single CDI. If you want to navigate by VOR you dial in the VOR freq into the Nav radio. You want fly an ILS or LOC you dial in the LOC freq into the same Nav radio. The GS signal is paired with the LOC freq so there's nothing extra the pilot has to do in order to receive and display the vertical gidance. While DME is a separate physical radio from the Nav radio, the DME freq is paired with the VOR/LOC navigation freq so again there are no "tuning" actions required by the pilot--it's automatic upon selection of the navigation freq, if DME is available.
 
I'm not making it difficult. It's important to know what is going on beyond just turning the knobs.

The initial question demonstrates either a lack of understanding of the system or a lack of understanding of how to fly IFR.
In addition to lacking lateral guidance without the LOC, the thing that you tune on your NAV radio is the LOC frequency. This is distict form the GS. There's no way to listen to the GS frequency, which is fine because it transmits no identifier. So without a localizer transmission, there's no ID. If you can't ID the station, you damned well ought not to be flying it.

This is in contrast (since you brought it up Todd) to the DME which does have its own ID (at a different time and pitch).
 
But does a non-pilot dispatcher really need to know it to that level? If so then I'll shut up and be quiet.
 
tsts4 said:
You guys are making this more difficult than it needs to be. While the VOR/LOC/GS signals all use separate receivers, in practice they are all integrated into a single Nav radio and display on a single CDI. If you want to navigate by VOR you dial in the VOR freq into the Nav radio. You want fly an ILS or LOC you dial in the LOC freq into the same Nav radio. The GS signal is paired with the LOC freq so there's nothing extra the pilot has to do in order to receive and display the vertical gidance. While DME is a separate physical radio from the Nav radio, the DME freq is paired with the VOR/LOC navigation freq so again there are no "tuning" actions required by the pilot--it's automatic upon selection of the navigation freq, if DME is available.
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flyingron said:
I'm not making it difficult. It's important to know what is going on beyond just turning the knobs.

The initial question demonstrates either a lack of understanding of the system or a lack of understanding of how to fly IFR.
In addition to lacking lateral guidance without the LOC, the thing that you tune on your NAV radio is the LOC frequency. This is distict form the GS. There's no way to listen to the GS frequency, which is fine because it transmits no identifier. So without a localizer transmission, there's no ID. If you can't ID the station, you damned well ought not to be flying it.

This is in contrast (since you brought it up Todd) to the DME which does have its own ID (at a different time and pitch).
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Yeah, I get it now. My confusion came from equating the VOR as THE CDI itself. It became crystal clear once I realized they aren't really the same thing. And here I am thinking I had a full understanding from reading that FAA information handbook we were given in the dispatch course. So what about the Radio Magnetic Indicater and the Horizontal Situation Indicater? Can these instruments be used to shoot an approach as well or are they enroute only?

tsts4 said:
But does a non-pilot dispatcher really need to know it to that level? If so then I'll shut up and be quiet.
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We do at least have to know what they are and how they work but not necessarily how to use it like a pilot since we aren't actually flying the plane. If an MEL item is sent to the dispatcher as an HSI, I have to know how that applies to me.
 
BlackManINC said:
So what about the Radio Magnetic Indicater and the Horizontal Situation Indicater? Can these instruments be used to shoot an approach as well or are they enroute only?
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An HSI most definitely--it's a CDI and directional gyro combined. An RMI can be used for an NDB approach as an ADF display and is very useful in conjunction with a Nav radio and VOR for flying a DME arc plus useful for enroute Nav as well.

Some HSIs also have RMI bearing pointers which make it an all encompassing navigation instrument.
 
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