vPAR Transponder - Editor
March 1, 2005
Michael Oxner


For anyone interested in setting up approaches or the QuadRadar, the Transponder not only retains its prior usefulness, but adds to its value. In the old Version 1.5, you would have to copy the position to the clipboard, open the Approaches.ini file in Notepad, paste the line, modify the name and save the file. It's much easier now.

Image 1 Clicking the "Open Approach Editor" button will expand the Transponder window greatly at the bottom to reveal a host of boxes and buttons awaiting your command. All of the Approach details required have boxes which allow you to add information and prepare approaches. By far the simplest and most accurate way it to position an aircraft in Flight Sim on the threshold of the runway and click the Start Reading FS State Data button. This will read state data at regular intervals and fill in the aircraft's Latitude, Longitude, Altitude, Heading and Magnetic Variation values. Once you have the aircraft positioned, click the Capture Data button on the right. This will freeze the Latitude, Longitude, Altitude, Heading and Magnetic Variation at that position from Flight Sim in the boxes. The aircraft's altitude is termed elevation, since that's more appropriate in the context of positioning something on the ground. The aircraft's heading will determine the course to follow to the runway, termed the Final Approach Course. The other data will be filled in with defaults and is explained below. While all of these values can be input directly without connecting to FS, you're not likely to be very accurate without a good source of Flight Sim information. Remember that real-world information will do little good if the airport in Flight Sim isn't where it should be.
 
Notice how when the Approach Editor is open, the Edit IP Lists button is greyed out? This is done to prevent the simultaneous opening of the Approach and IP List Editors. Closing the Approach Editor will enable the Edit IP List button.

Editor With Captured Data Clicking the Capture Data button will populate the other boxes, except Approach Name, with default data. The glidepath will be set at 3.0, for example. This is a fairly standard angle for glidepaths, although the program will allow you to run with anything from 0.0° to 7.0° through the drop-down list or directly by typing in a value. GPI is the Ground Point Intercept for the Glidepath. Rarely will you want to specify the runway threshold as the place for the aircraft to touch down. The larger the aircraft, the further back on final the wheels will actually touch the ground, putting most of you aircraft into the approach lights. Typically you'll displace the touchdown area about 1,000 feet down the length of the runway, so 1,000 feet is the default. This is, of course, adjustable before saving, so just make sure you put the desired amount in.

Control Limit is the horizontal extent of radar control. Some may not require this value, so it can be set to zero to prevent display on the Quad Radar. This could be analogous to the visibility requirement of an ILS and is set by default at 5/8 of a mile to work in harmony with the GPI. Typically 1/2 mile would be a limit, with the default of 1,000 feet for GPI, puts the Control Limit line about 1/2 mile on final.

Published DH is the Decision Height for the approach. If the pilot does not have visual contact with the runway environment at this altitude, he is supposed to initiate a missed approach. By default, this value will show up as 200 feet above the elevation, with the decimals rounded off. In the old Quad Radar program, this was merely for information. In the new Quad Radar program, this is actually drawn on the Elevation view of the PAR display.

The last thing the Capture Data button will do is place your cursor in the Approach Name edit box. This allows you to type a name for the approach, which must be unique in the file. Speacking of the file, you have to tell theTransponder where the Approaches.ini file is before it can do its duties for you. Clicking on the "Select Approach File" button let you search for it with a standard windows file open dialog. Once you've found it, the name will appear in the edit box right below this button and you're set to save.

Editor Saving Clicking the Append Approach button will check the data for proper formatting and save what it finds to the file specified in the Approach File edit box. If you haven't selected the file, the program will remind you. You'll get no indication if the data you entered is wrong, though. The program can't be sure you've entered things you shouldn't. The formats are simple, but putting a wrong character in can change the result. For example, accidentally typing in "6+98" for Published DH could happen by hitting the numpad <PLUS> and the numpad <9> simultaneously. The program will record this string as "6" because it stops the conversion process when it finds the first non-numeric character. If you are working with decimals, the two values it accepts are '.' and ','(Period and Comma). This is to allow international usage, since many countries use comma as the decimal separator. Negative signs('-' only), such as for Lat and Lon, are acceptable as they are recognized as numeric characters when numeric characters follow them.

When you click Append, the program will review the Approaches.ini file to see if there is already an approach with that name in the file. If so, it will tell you and offer to let you overwrite it. If you overwrite, it will replace this approach. If you cancel, it will place the cursor back in the Name box so you can enter a new name. Approach names must be unique in the file. Since there are different scenery packages out there, it's quite possible to have aircraft flying to the same airport and not lining up correctly on final. As a PAR controller, you should be setting up approaches with some indication in the name of what scenery you used so you and the pilot know. You should use a naming convention and stick with it for ease of organization. For example, I recommend using the airport ICAO designator and runway number, with a comment including Flight Sim version and/or scenery package. "CYZX26_FS2K2_Default" for example. If you type in a name with spaces in it, the program will replace them with underscores, since spaces are not allowed in approach name.

The Clear Boxes button is pretty self-explanatory, I figure.