Offset Localizer??

[Mtnjam]

Anyone know about offset localizer's for an ILS??? Where do you find this info?? The only thing I can come up with is that if you're shooting an ILS Rwy. 26 and the Final Apprch. is 257 degrees, then it's offset 3 degrees??? I keep hearing there is a place to find this info, but am unsure where to find it on Jepps. Thanx........

 

[pilotman2105]

Anyone know about offset localizer's for an ILS??? Where do you find this info?? The only thing I can come up with is that if you're shooting an ILS Rwy. 26 and the Final Apprch. is 257 degrees, then it's offset 3 degrees??? I keep hearing there is a place to find this info, but am unsure where to find it on Jepps. Thanx........

Not necessarily in your example. A runway can have a heading of 257 and be labelled as runway 26.

Try looking on the airport diagram and referencing that with the info on the approach plate. The airport diagram should have the runway heading information (more exact than just tacking on a 0 to the end of the runway designation).

 

[Uncle Sparky]

Unless it's an LDA or SDF, it shouldn't be offset. The published runway heading may change(due to natural phen. or to avoid multiple runway confusion)but the localizer antenna is fixed in the ground.

 

[A Squared]

OK, first off, the runway heading: Pilotman alluded to this, but didin't tell quite the full story. The actual magnetic bearing of Runway 26 could be anything between 255 to 265.

Like pilotman said, find the actual runway bearing on hte diagram and compare to the Final Approach course.


>>>>>>Unless it's an LDA or SDF, it shouldn't be offset.

Nope, not true, an ILS Localizer may be as offset from the actual runway heading, up to 3 degrees if memory serves. AN airport I fly int frequently has an offset ILS. it's only a few degrees, but it is very apparent while in final.

 

[Uncle Sparky]

I understand that a standard ILS has a degree of tolerance from runway heading but can you show me an ILS that is published as offset, in the same fashion that a non-standard GS is for example?

 

[KeroseneSnorter]

I understand that a standard ILS has a degree of tolerance from runway heading but can you show me an ILS that is published as offset, in the same fashion that a non-standard GS is for example?

I am going from memory here as my charts are in the airplane but I think Roanoke may have an example of what you are looking for. I seem to recall the ILS being offset for one of their runways. It may be an LDA though.

Getting older, the brain bucket is not as full as it used to be so I may be thinking of another airport.

EDIT: After straining the brain some more I don't think Roanoke was it, I know it was one of those mountian cities (If you can call the east coast hills mountains!) Anyhow as said before it is not offset much but it is kind of strange when you break out and have to adjust.

Come to think of it, I normally shoot an ILS doing S turns anyhow, so I should be used to it!!

 

[Uncle Sparky]

Getting older, the brain bucket is not as full as it used to be so I may be thinking of another airport.

Know what you mean...........between memory degradation and the fact that....... when the heck have I ever even done an LDA? I had to dig up the dusty old textbook. Localizer and LDA DIMENSIONS were the only thing that I could find. I left the big red, white and blue sleeping pill(FAR/AIM) at work, I'll have to see if it's in there.

 

[lawfly]

Offset Localizer?

AIM page 5-47 (para. 5-4-12) in a discussion of ILS approaches to parallel runways states:

"At some airports one or more parallel localizer courses may be offset up to 3 degrees. Offset localizer configurations result in loss of category II operations and an increase in decision height (50 feet)."

Not saying that's all there is on the subject, but that's what I came across in a quick flip through the AIM.

Would probably be informative to review the particular approach chart(s) in question.

 

[A Squared]

I understand that a standard ILS has a degree of tolerance from runway heading but can you show me an ILS that is published as offset, in the same fashion that a non-standard GS is for example?

Not to get into a discussion on semantics but "a degree of tolerance from runway heading" *is* an offset. It's just a smaller offset than an LDA is allowed. The approach I'm referring to is Kotzebue ILS DME RWY 8. The plate says: "LOC CRS offset 1 degree from Rwy centerline"

I'd forgotten that it was only one degree. As noticable as the offset is, I'd kinda thought it was closer to the maximum 3 degrees.

 

[Mtnjam]

Ils 18

I think one of the approaches that had or does have an offset localizer would be an ILS at DFW. Maybe 18?? So I assume that if an approach has an offset localizer, then it would be clearly labeled on the approach chart? I do know it would not exceed 3 degrees, otherwise it would have to be an SDF or LDA.

 

[Uncle Sparky]

Dang!.......Kotzebue?......Did you have to dig that up or have you been there?

Well, if Kotzebue(PAOT) is standard for an offset ILS, than the answer to the question is:
The info is in the facility box on the planview(including notification of the existence of the offset/the degree of offset/and the rwy mag-hdg.) and there is also a block indicating offset LOCALIZER with a callout attached to a smaller block next to the runway.

 

[A Squared]

Dang!.......Kotzebue?......Did you have to dig that up or have you been there?

Been there, more than once.

Well, if Kotzebue(PAOT) is standard for an offset ILS, than the answer to the question is:

The info is in the facility box on the planview(including notification of the existence of the offset/the degree of offset/and the rwy mag-hdg.) and there is also a block indicating offset LOCALIZER with a callout attached to a smaller block next to the runway.

Yeah, that's what I see on my Jepps. Looking at the NOS plate though, I don't see any indication that it's offset, other than on the planview the runway appears not to line up with the final approach course. I guess if you were looking carefully, you'd notice it, but I don't see any other way of seeing it.