Welcome Guest. Sign in or Signup

2 Answers

GPS MAP for LOC/DME

Asked by: 2139 views , , , , ,
Instrument Rating

When you load the Garmin 430 for CRQ ILS or LOC/DME RWY 24, it references the MAP as RW24. 

So if you are flying just the LOC/DME, does this mean your MAP will be defined by 0.0 on your GPS (and not 0.9 DME as shown on the profile view)?

If I wanted to verify I was at HUSET intersection, would I have to add 1.8+1.5 NM (and not 4.2 DME as shown on the profile view)? This is because the MAP is defined as RW24 and not I-CRQ like a conventional DME unit. This seems like a cumbersome method to identify fixes...

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

2 Answers



  1. Wes Beard on Feb 01, 2014

    So if you are flying just the LOC/DME, does this mean your MAP will be defined by 0.0 on your GPS (and not 0.9 DME as shown on the profile view)?

    Yes. The GPS distance always counts down to the next fix. In this case the MAP at the end of the runway will read 0.0 when over it.

    If I wanted to verify I was at HUSET intersection, would I have to add 1.8+1.5 NM (and not 4.2 DME as shown on the profile view)?

    Some FMS or GPS software does not display any waypoints inside the FAF to the MAP. If this the case for you, then you will need to add the distances of 1.8 and 1.5 to get 3.3. Notice you can also take 4.2 minus 0.9 (MAP) to get the same value.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  2. John D Collins on Feb 02, 2014

    Also, in some approaches, the localizer MAP point is not at the threshold, but at a short distance from it (example 0.5 NM). The MAP is usually specified as a DME distance, so if the threshold was at 0.9 DME, in my example, the MAP might be at 1.4 DME. The GNS430 shows the MAP to be at the threshold, but the pilot must determine the actual MAP by calculating the distance to the threshold, in my example, the GPS would read 0.5 at the MAP.

    0 Votes Thumb up 0 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.