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Questions tagged [localizer]

A localizer is a radio navigation aid used to aid aircraft when approaching an airport to land.

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3answers
102 views

When do I execute a missed approach on a LOC approach when I can't identify the MAP?

According to AIM 5.4.21(b): When an early missed approach is executed [...] fly the IAP as specified on the approach plate to the MAP at or above the MDA or DH before executing a turning ...
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2answers
402 views

How to fly LOC approach when IAF is a specific DME from LOC, but LOC has no DME?

I was looking at this approach plate and noticed that SNOWL is an initial approach fix, and that it's charted to be 6.4 NM from the localizer ...
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1answer
69 views

What are the procedures for flight checking a glideslope and localizer?

What are the FAA and ICAO requirements and procedures for flight checks and calibration of glideslope and localizer transmitters? I'm interested in both the engineering and piloting aspects.
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1answer
131 views

How the Log Periodic Dipole Antenna of Localiser help in varying modulation depth?

Here Albert Helfrick speaks about 40% modulation depth for each tone in a localiser radio signal. However latest manuals of ILS manufacturers and google source speaks about 20% modulation depth, not ...
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0answers
153 views

What is space modulation? Its application is instrument landing systems [duplicate]

How the modulation depth changes with respect to azimuth for the Receiver of aircraft when it is using localiser or glideslope?
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3answers
391 views

Why are the modulation depths of the localiser and glideslope different?

Why do we use a modulation depth of 20% (for 90Hz and 150Hz each) in the case of the localiser and 40% (for 90Hz and 150Hz each) in the case of the glideslope? Why not use 20% for both?
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2answers
538 views

Why do localizer/glideslopes use 90/150Hz specifically?

Why is it that localizer and glideslope system are using 90 Hz and 150 Hz frequencies only, instead of some other LF such as 75 Hz? Part two of my question: How does the modulation depth differ for ...
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2answers
2k views

How is varying modulation depth achieved by localizer ground transmitters?

An approaching aircraft's navigation receiver uses the difference in depth of modulation between the 90Hz and 150Hz signals which are amplitude modulated onto an RF carrier (on a channel between ...
7
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1answer
431 views

Telluride (KTEX): Why is the localizer antenna located where the glideslope should be?

Telluride (KTEX) in Colorado, USA: Source As visible, the localizer antenna for RWY 09 is located where the glideslope antenna is usually found, abeam the touch down zone. The localizer is normally ...
3
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1answer
2k views

What's exact offset degree dividing localizer and LDA?

When a localizer is offset at an angle with the runway track, it functions as a "Localizer Directional Aid or LDA." What's the exact offset degree dividing them? Any offset degree greater than 0 makes ...
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1answer
331 views

What is the reason to have LOC/VNAV landing method?

What is purpose of mixing LOC/VNAV in this landing method?
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3answers
614 views

Can a pilot transition from a localizer approach to an ILS approach?

I was recently looking at the approach to RWY 8L at Honolulu, Hawaii (PHNL). Looking at the approach IAFs, I see the LOC RWY 8L approach has many different options, and has an intercept altitude at 2,...
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2answers
544 views

If DME is required, why have non-DME minima?

I was looking at the ILS or LOC RWY 9 at KJZI today and I noticed that it had lower minima for when you can identify an intermediate fix (YOCUB). That made sense, but the entire approach requires DME....
7
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1answer
566 views

Is a VHF NAV receiver inherently capable of processing a LOC signal?

These last few weeks I have been flying a couple of different aircraft that had inoperative glideslope capabilities, but I was able to fly LOC approaches without trouble. In my career as a pilot and ...
8
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1answer
424 views

What is the reason for not providing glide slope guidance on the western approach to Innsbruck?

When approaching Innsbruck (ICAO: LOWI) from the east, you intercept a localizer (111.10) which also provides glide slope indication. I believe this should be used just for guidance and not for A/P ...
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2answers
553 views

Can the ILS be shut down? [closed]

Can the ILS be manually turned off? Not by the pilots inside the cockpit by simply shutting of the ILS button, but rather by a 3rd party personnel, such as an ATC or a ground crew member. ATC shuts ...
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3answers
2k views

What criteria does ATC apply to determine if an aircraft is established on the localizer if the pilot does not report it?

How close in time or distance will ATC let a pilot fly to the localizer, before cancelling the approach clearance, where the pilot has not reported being established? Is it the controller's call when ...
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2answers
944 views

Why do some back course operations use normal sensing?

So the LOC/DME-E approach to KASE lists for the missed approach course to use the I-PKN localizer, but then there's a note 'course outbound is normal sensing'. Does that mean that in effect, this ...
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2answers
16k views

How to calculate the vertical profile for a LOC only approach?

I am kind of stuck for calculating a descent path on the ILS RWY 7 approach into KORL. Assuming the glide slope is not available and you have to use the localizer only, what is the best way to ...