Offset Localizers | Localizer and LDA Approaches

An ILS has a glideslope and localizer for guidance, but what happens when the localizer isn't aligned with the runway centerline exactly? Here are some examples of offset localizer courses.

[AlyssaM_InfoSec]

Appreciate this video so very much. A friend and I who are both going through our IFR training and safety piloting for each other discovered this on the ILS 21 at KMSN. Missed the notation on the IAP and couldn't figure out why the LOC had us left of centerline. Then I discovered that notation and subsequently found this amazing explanation of it. So thank you for this!

[larrybueno]

Excellent! I love how thorough your explanations are. You deserve being the lead in the ground school industry.

[thebadgerpilot]

Last week I did an offset ILS on a practice flight. Didn’t even know it was a thing until my safety pilot and I debriefed. Now I know where to look and include it in my approach brief!

[wizardgmb]

Thank you for the video follow up to our previous discussion. You're a pretty nimble video producer! I'm not a pilot, I don't play one on TV and I don't stay at a Holiday Inn Express but I'm working on a novel with a big dose of general aviation. Your videos help me make the aviation portions accurate and understandable!

[alanhawse]

As always excellent presentation... the real conclusion for me is fly the RNAV31...

[rgardner]

So… knowing that you are flying an approach with an offset localizer, should you then fly with, say, a quarter to half-scale deflection knowing that it will eventually put you closer to the centerline as you proceed inbound?

[.e]

If the maximum allowable offset for an LDA is 15 degrees, then how come the LDA-C at Van Nuys is offset almost 90 degrees?