RyDawg82
Topic Author
Posts: 833
Joined: Fri Sep 14, 2001 8:30 am

Dual Curved Localizers At Kind

Thu May 17, 2007 10:31 pm

Hello,

While departing runway 23L at KIND this past Tuesday I noticed an odd localizer array. The array looked like 2 localizer antennas that were curved with one in front of the other. They were located about 1500 feet down the runway on the east side between taxiways D-2 and D-3. I cannot find any information on what kind of system this is. Does anyone have any information?

Ryan
You can take the pup out of Alaska, but you can't take the Alaska out of the pup.
 
Goldenshield
Posts: 5008
Joined: Sun Jan 14, 2001 3:45 pm

RE: Dual Curved Localizers At Kind

Thu May 17, 2007 11:31 pm

For those who want a visual, this is what he's talking about:

Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 12:41 am

Maybe it is the localizer antennae...but that's odd. I thought the localizer antenna was always at the opposite end of the runway... confused  I do know, however, that the FAA gives you up to 30 deg. of tolerance (i.e. difference between the heading the localizer tracks you in on vs. the runway heading) before the approach is considered to be an LDA approach.

Perhaps we can use this thread to clear up another question of mine. How do air carrier airports use the same localizer frequency for both ends of the runway? For example: ILS RWY 10L and ILS RWY 28R at PDX both use the same localizer frequency: 111.3. At most GA airports, the back side of the same localizer antenna would be reverse sensing...and I do believe I've seen standard localizer antennas at the end of 10L and 28R at PDX  Wink
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
Mir
Posts: 19107
Joined: Mon Jan 05, 2004 3:55 am

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 1:37 am

Well, I can't see any approach there that lists a localizer in that position, and I've never heard of a curved localizer. So I have no clue what the hell that is.

Quoting KELPkid (Reply 2):
Perhaps we can use this thread to clear up another question of mine. How do air carrier airports use the same localizer frequency for both ends of the runway? For example: ILS RWY 10L and ILS RWY 28R at PDX both use the same localizer frequency: 111.3.

One is off when the other is on. This is a good way to reduce the number of frequencies used, since presumably an airport will not be doing ILS approaches to opposite ends of the same runway. HPN is the same way, and once when I was doing my instrument training, we came in to do the ILS to 34. When we left, they had been using 16, and apparently they had just changed over. The weather was good, so everyone was doing a visual approach (except us). We tuned in the frequency and identified the station, but it had the code for the 16 ILS and not the 34 ILS. We had to query ATC three times before the right code started coming over the frequency. Moral of the story: always identify the station!  Smile

Quoting KELPkid (Reply 2):
I thought the localizer antenna was always at the opposite end of the runway...

Not always. The JFK 22R ILS is offset from the runway, and the localizer itself is located about two-thirds of the way down the runway, to the left.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
Goldenshield
Posts: 5008
Joined: Sun Jan 14, 2001 3:45 pm

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 4:39 am

After doing a little research, I've found the basic explaination of this setup.

The premise is that of an experimental instrument landing system using Alford loops to aid in providing better missed approach guidance.

That's all I can get with the free stuff I can find. If anyone's willing to pay the cash for to read up further, please, fill in the details.  Smile
Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
 
timz
Posts: 6116
Joined: Fri Sep 17, 1999 7:43 am

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 7:18 am

Quoting Mir (Reply 3):
The JFK 22R ILS is offset from the runway

You just mean it has to be "offset", since the antenna isn't on the runway centerline?

(The chart shows ROSLY on the localizer, and ROSLY is 15-20 ft SE of the runway extended centerlline.)
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 9:48 am

Quoting Goldenshield (Reply 4):
After doing a little research, I've found the basic explaination of this setup.

The premise is that of an experimental instrument landing system using Alford loops to aid in providing better missed approach guidance.

Huh? The missed approach for 23L or 5R has you climb and hold at a LOM for the crosswind runway...that's wierd, although I guess they worried that you might not track the localizer correctly during the climb to 1500' before initiiating the turn for the missed...  Wink
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
Mir
Posts: 19107
Joined: Mon Jan 05, 2004 3:55 am

RE: Dual Curved Localizers At Kind

Fri May 18, 2007 11:40 am

Quoting Timz (Reply 5):
You just mean it has to be "offset", since the antenna isn't on the runway centerline?

Well, offset in the sense that if you are tracking directly down the localizer, you will run off the side of the runway before you run off the end. Normally the center of the localizer is down the center of the runway - not so with the JFK 22R localizer.

If you look at the airport diagram on the approach plate ( http://map.aeroplanner.com/plates/FaaPlates_pdfs/00610I22R.PDF ), you'll see the location of the LOC/DME antenna, between 4L and 4R, and south of 31L.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
Boeing7E7
Posts: 5512
Joined: Sat Jul 31, 2004 9:35 pm

RE: Dual Curved Localizers At Kind

Sat May 19, 2007 12:33 am

Quoting RyDawg82 (Thread starter):
While departing runway 23L at KIND this past Tuesday I noticed an odd localizer array. The array looked like 2 localizer antennas that were curved with one in front of the other. They were located about 1500 feet down the runway on the east side between taxiways D-2 and D-3. I cannot find any information on what kind of system this is. Does anyone have any information?

It's either this:

Quoting Goldenshield (Reply 4):
The premise is that of an experimental instrument landing system using Alford loops to aid in providing better missed approach guidance.

Or an LDA test of some sort. Usually you see this with offset approaches. Not sure why IND would need one unless they are extending the runway at both ends at the same time and want it to remain active. Both runway ends have localizers in place.

Quoting KELPkid (Reply 2):
How do air carrier airports use the same localizer frequency for both ends of the runway?



Quoting Mir (Reply 3):
One is off when the other is on.

Yup.

Chalk it up to weird?

[Edited 2007-05-18 17:48:34]
 
Fly2HMO
Posts: 7207
Joined: Sat Jan 24, 2004 12:14 pm

RE: Dual Curved Localizers At Kind

Sat May 19, 2007 1:38 am

I've seen this same setup as well in FLG and I actually used it when flying in on the ILS. The localizer is offset 3 degrees from centerline. What was very, very interesting is that there was no G/S antenna visible, at least not the usual tower type you'll see next to the aiming points, yet there is a usable G/S signal and it has standard CAT 1 mins.

I don't think these have to do much with offset approaches because I've seen standard localizer antennas where the whole thing is actually offset a couple of degrees.
 
phxpilot
Posts: 59
Joined: Fri Jul 22, 2005 5:25 am

RE: Dual Curved Localizers At Kind

Sat May 19, 2007 4:35 am

The G/S antenna at FLG is on the West side of the runway between the runway and taxiway. It is a set of three antennas low to the ground. The only array of this type I have ever seen.
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: Dual Curved Localizers At Kind

Sat May 19, 2007 4:51 am

Quoting Phxpilot (Reply 10):
The G/S antenna at FLG is on the West side of the runway between the runway and taxiway. It is a set of three antennas low to the ground. The only array of this type I have ever seen.

I suppose that would explain the hold short lines at FLG being so far back from the runway...(sheepishly admitting to accidentally crossing it while taxiing for departure for the first time at FLG, but turning back after realizing the mistake and apparently before the tower controller saw that I had done it  blush  ).
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
timz
Posts: 6116
Joined: Fri Sep 17, 1999 7:43 am

RE: Dual Curved Localizers At Kind

Sat May 19, 2007 11:26 am

Quoting FLY2HMO (Reply 9):
I've seen standard localizer antennas where the whole thing is actually offset a couple of degrees.

But the localizer beam still crosses the runway threshold? So the antenna has to be a couple hundred feet off the runway?
 
Fly2HMO
Posts: 7207
Joined: Sat Jan 24, 2004 12:14 pm

RE: Dual Curved Localizers At Kind

Wed May 23, 2007 11:58 am

Quoting Phxpilot (Reply 10):
The G/S antenna at FLG is on the West side of the runway between the runway and taxiway.

O yeah, I remember those short thingies. I thought they were part of the LOC and it was all (GS and LOC) integrated into one antenna. In hindsight, that wouldn't really be possible, or would it?

Quoting Timz (Reply 12):
But the localizer beam still crosses the runway threshold? So the antenna has to be a couple hundred feet off the runway?

Yup.


I think I recall seeing some pics in the database of certain european airports with a similar setup...

-----
Never mind, FLG does have a standard LOC antenna. It is halfway down the rwy, north side I just saw it in google earth, and it seems like its canted exactly 3 deg towards the rwy. I actually am starting to remember seeing it at an odd location when I went there a while back...

Quoting Phxpilot (Reply 10):
The only array of this type I have ever seen.

Actually, the setup at KIND looks identical to what I saw in FLG per the satellite images.


So, what we're really looking at really, is a different type of G/S antenna, and not a localizer antenna.

[Edited 2007-05-23 05:19:08]

Who is online

Users browsing this forum: No registered users and 24 guests