Welcome Guest. Sign in or Signup

1 Answers

Back course localizer approaches

Asked by: 914 views , ,
Instrument Rating

I have been practicing the back course localizer approach to runway 2L in Santa Ana (SNA) using my PC simulator. I switch the CDI from GPS to VLOC on the simulated Garmin 430 just before getting to MINOE (IAF/IF). I get reverse needle indications on the separate VOR/LOC gauge and normal heading indications on the Garmin 430 screen (Page 1 of NAV).  My understanding is that the heading indications on the Garmin 430 screen are GPS based (instead of ‘corrected’ BC localizer indications).  Consequently, in order to be legal I am supposed to disregard these indications and fly the approach using the separate VOR/LOC gauge.

Could somebody please answer the following questions:

  • Is my PC simulator representing correctly BC approaches using the Garmin 430 and the separate VOR/LOC gauge?
  • Are my above statements about the heading indications in the G 430 correct?
  • Could I use the GPS to fly to NEWPO (the final fix) and switch the CDI to VLOC there?
  • Should I have a DME in the plane to fly this approach, assuming that I don’t want to time the approach, since the Garmin distance information is based on GPS and GPS is not considered legal to fly a localizer approach?

Thanks

1 Answers



  1. Russ Roslewski on Oct 06, 2016

    You have most of it right, with a few minor corrections.

    > Is my PC simulator representing correctly BC approaches using the Garmin 430 and the separate VOR/LOC gauge?

    Yes.

    > Are my above statements about the heading indications in the G 430 correct?

    I think you mean “course deviation indications”, but yes.

    >Could I use the GPS to fly to NEWPO (the final fix) and switch the CDI to VLOC there?

    No, actually. If it was a VOR approach, the answer would be yes, but according to the AC on GPS substitutions, you must use actual LOC guidance for all guidance on a LOC, or LOC-BC course: http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_90-108_Chg_1.pdf

    Of course, you can always “monitor” the GPS data on your secondary display (the GPS itself) while officially navigating using the LOC-BC data on your primary display.

    >Should I have a DME in the plane to fly this approach, assuming that I don’t want to time the approach, since the Garmin distance information is based on GPS and GPS is not considered legal to fly a localizer approach?

    DME not needed, GPS is substitutable (new word?) for DME, see the above AC.

    +1 Votes Thumb up 1 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.