PROBLEM:
Certain occasions may arise resulting in the need to change the coverage on a subscription either temporarily or permanently. Due to the variety of airborne operations today and the versatility of modern aircraft, many clients need the ability to create custom options tailoring our existing coverage regions to better suit their operational/avionics needs. This can be done from within the JDM program on either the Windows or Mac platforms.

CAUSE:
The need to select a different coverage could be as a result of an error in the current coverage (due to size of the download or specific data issues). Another reason to select a different coverage would be due to media size constraints regarding updating of a particular aircraft. For example an aircraft with a World Wide subscription needs to get from Atlanta to Mobile for further service and they only have a 512 Mb USB available. The need to change an existing coverage is most frequently found with Pro Line and Honeywell subscriptions.

RESOLUTION:
To edit or tailor your existing coverage, you first want to choose the Download Only button in JDM to download the charts to your computer. Once the download has completed, click the Select Coverage option pictured below, then transfer the charts database to the storage device after saving the edit.

NOTE: It's possible to filter the airports by either runway length, or by geographical region (or both at the same time). Filtering by runway length may be a better option for operators with larger aircraft that cannot make use of shorter runways.

Click Select Coverage (note this example references a Pro Line charts service)




You should see your coverage areas as well as the file size and number of airports on the left hand margin of the Select Coverage window (see image below). The most important part of subsetting your coverage is changing the number of airports (which in turn changes the file size). For this reason it is important to note the number of airports in the airport count prior to editing your coverage.



The easiest way to change the airport count is through the filter by runway length tool or modify exclusion airports tool (also on the left hand margin of the Select Coverage window under the selected coverage details). One example of how to change the airport count would be to click on the Runway Length Filter then choose a length appropriate to their aircraft's minimum operational limitation (3000 feet in the image pictured below). Next you would click the "X" in the upper left to close the Airport Runway Filter box then click the Save button on the bottom left to close the Select Coverage window prior to transferring the data. You may also add an location to the Exception Airports which prevents individual airports from being filtered out of the subset.



Changing the coverage area on the map is another way to change the coverage size if a specific region/size is needed. Hover over the edges of the selected area on the map and then left click with your mouse to drag/change thelimitations by including or excluding sections of the existing coverage box on the map. Remember to click on the APPLY SELECTION button above your region selection box then click Save on the bottom left to close this window. To start over with the full coverage click the CLEAR SELECTION button on the top left of the map.

Click the Save button, then transfer the subset data file to your storage device as you normally would. If JDM indicates that no transfers are remaining, refresh JDM by clicking the JDM menu (top left of the program where you see JDM) then choose the Refresh JDM option.

THIS STEP IS OPTIONAL (depending on your needs). To remove the selected coverage area and return to transferring your normal full subscription start by clicking the Select Coverage once again to edit the coverage and then Clear Selection. Remember to click the Save button when done and close the coverage window.

Please note that subsetting only applies to the airports in your Charts database - associated navigation databases, obstacle databases etc. are not effected by subsetting.

If your need to subset your charting coverage is due to a diagnosed Pro Line file size issue then you may find additional useful information in the associated knowledge article found here:Charts load fails at 20-99% on a Collins Aerospace Pro Line system

If your need to subset is due to missing airports in your Honeywell system please refer to the related article: Airports are missing from the charts database in a Honeywell Apex or Epic INAV system

If you are needing to subset your Avidyne charts due to media size limitations please see the related article: "CMax Data Update failed ... not enough space" when updating charts on an Avidyne EX500/5000 MFD