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5 Answers

DME or ADF required KLRU.

Asked by: 3327 views Instrument Rating

WHY ADF and how ADF? the approach chart doesn't have an ADF frequency anywhere? Why is it on the approach plate? Is this an uncommon thing? I know the closest ADF but it isn't on the chart. How do I use it?

5 Answers



  1. Jon on Oct 11, 2011

    If you’re talking about the ILS/LOC 30, there is an ADF frequency on the chart – it’s the locator outer marker (LOM) and initial approach fix on 206 kHz.  If you don’t have an ADF, you can use DME to locate the IAF as 7.3 nm from the localizer DME (I-LRU).

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  2. Bob Watson on Oct 11, 2011

    I’m looking at the ILS/LOC RWY 30 chart (http://tiles.skyvector.com/sky/files/tpp/1110/pdf/00869IL30.PDF) and the ADF or DME look like they are used to identify the IAF, FAF, and the MAP. The IAF uses a LR NDB as a compass locator at the OM on 206 kHz and the FAF is identified by the 7.3 DME from the I-LRU localizer/DME.
    The COSES intersection is identified by either the 43.4 DME on the 094-degree radial from the DMN VORTAC or the intersection of the 094-degree radial and the 332-degree bearing to the LR NDB.

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  3. Bob Watson on Oct 11, 2011

    Correction, the ADF is used to identify the holding fix, not the MAP.

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  4. Koehn on Oct 11, 2011

    The MSA and the LOM/IAF both use the LR NDB, 206 KHz. You should be able to substitute an IFR GPS for ADF/DME in this case.

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  5. John D. Collins on Oct 11, 2011

    The DME is required for the “LOC Only” approach to locate the FAF at JOSPO and the MAP at 1.4 I-LRU.  It is also used as an alternate method of locating the missed approach hold waypoint COSES.  If you do not have a DME, then only the ILS minimums are applicable, as there is no way to determine the location of the FAF.  With the ILS and GS, the PFAF (Precision Final Approach Fix) is located at the intersection of the GS and 6400 MSL and the missed approach point s based on the DA. Without a DME, you need an ADF to locate the missed approach hold waypoint at COSES by using the LR NDB bearing of 322 degrees. The ADF is also required to use the feeder route from CRATT to navigate the route on the 053 bearing to the LR NDB.

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