ADDS Flight Path Tool Help

Flight Path Tool Tutorial

This section provides information on effectively using the Flight Path Tool. Please refer to the FAA AIM for the regulatory issues related to the use of this experimental software and the experimental weather products.

The following topics are covered:

Flight Path Tool Display

This screenshot points out important features of the Flight Path Tool:

  • Data inspection window
  • Primary display panel
  • Altitude controller
  • Map scale reference
  • List of displayed data/times
  • Colorscale/Legend
  • Time controller
  • Map overview panel
  • Animation controls

Weather overlays

Weather overlays in the Flight Path Tool include the primary relevant aviation weather products from the NWS. At this time, the available overlays are wind barbs, METARs, TAFs, PIREPs, AIRMETs, ,SIGMETs, and NCWF 1 Hour Performance. These data are generally unscheduled in time; the application attempts to refresh with the latest data every few minutes. All the overlays have specific icons to represent the weather conditions. A text box appears with the original NWS text message when you move your screen pointer over any icon.

The wind barb overlay is partly associated with the 3D grid of wind speed. Select the wind speed product from the Weather menu to activate the wind barb overlay. Place the cursor over a wind barb to produce a pop-up text message of the wind direction (degrees true not magnetic) and speed. A reference for how to interpret the wind barb presentation is found here. The density of the wind barbs matches the wind speed data but would be illegible on the screen if all points were shown simultaneously. Therefore, the software decides which wind barbs to plot automatically, but users may use the configure menu to control the density manually.

Enabling specific gridded weather products will also activate corresponding AIRMETs and/or SIGMETs. For instance, choosing either icing product will automatically activate the icing AIRMETs and SIGMETs. Choosing flight category, ceiling, or visibility automatically activates the IFR and mountain obscuration AIRMETs; whereas choosing either radar or convection product automatically activates the display of convective SIGMETs. Once enabled, these overlays can be turned off manually using the Overlay menu, but they are programmed to return to this default behavior once you switch to one of the listed choices.

Effective use of zoom/pan and saving custom configurations

The View menu contains options related to zooming and saving, deleting, and showing previously-created regions of interests. To zoom in, simply double-click with the left mouse button over the spot you wish to zoom into on the primary display panel. Consecutive zoom operations continue to zoom until the software can no longer display anything reasonable. To zoom out, you can single-click with the right mouse button. To keep the same zoom level but shift/pan the map in a specific direction, simply left-click and drag (while continuing to depress the mouse button) the map in the direction you desire. Letting go of the mouse button will stop the pan operation. An optional zoom/pan toolbar is available to use instead of the mouse. If you have the toolbar enabled, the mouse zoom/pan operations automatically become disabled and will not function until the toolbar is hidden again.

The vertical cross-section viewing window can also be zoomed using the same mouse operations. Using this method, users can reveal more vertical detail but the horizontal axis will always retain the full flight path. In other words, the zooming is only done in the vertical (altitude) dimension. Once you create a plot showing a specific region you wish to save, use the View→Save View option and enter a name for the view in the Save a favorite view dialog box. For consistent usage of the tool, the saved views are far quicker than using the various zoom/pan operations (mouse or toolbar) to focus directly on your area of interest. Besides saving the geographic location shown on the display, the various data layer choices are saved as well. Therefore, you could save a region showing one set of weather products, then switch weather products and save the same geographic region with different weather products under a different name. The View→Delete View option obviously removes a saved view from your list. The View→Default View option exists to jump-start the application (the next time it is launched) directly to your saved settings. View→Continental U.S. option is a quick way to zoom all the way out to the full ConUS if you wish to see more distant weather or decide to start from scratch to create a new zoom region. Finally, a map overview panel is provided for reference to get an idea of the surrounding area. The red box shown in the overview represents the region shown in the primary display panel and that red box can be moved or resized using the left mouse button but is not an effective means for performing a number of zoom/pan operations.

Obtaining a view along flight route

Use the Tools menu and choose Flightpath, then pick either Click Way Points or Enter Station List. If you pick the first option, then click once with the left mouse button in the main display panel to start the path, then once again for each point along the desired route. When you reach the desired end of the flight path, double-click the left mouse button. Alternatively, right mouse click and pick Submit path. If you prefer to enter a list of abbreviations to describe a flight path, then pick the appropriate menu item. If so, a new dialog box appears and you can enter a series of abbreviations to describe the route. At this time, you must enter four-letter ICAO abbreviation like KDEN, not the three-letter airport identifiers. As an example you can enter the text string: KDEN, KSNY, KLBF, KOMA, KDSM, KORD. Click here to view a screenshot of a view along a flight route.

Viewing a time-series of past, present, and future weather at a station (meteogram)

Use the Tools menu item and choose Meteorogram, then pick either Click Station or Enter Station. If you pick the first option, then click once with the left mouse button in the main display panel on a METAR or TAF reporting location (you must enable one or both overlay options in the Overlays menu). If you pick the second Meteorogram menu item, then a new dialog box appears and you can enter a four-letter ICAO abbreviation like KDFW. Click here to view a meteogram.

Time controller and animation

The time controller interfaceallows users to alter the time of the gridded weather products. Overlayed data such as

METARs, PIREPs, TAFs, AIRMETs, and SIGMETs are affected by changes to the selected time as well. The current time is indicated by the red vertical line and the corresponding UTC and local times are shown above the red line. The selected time of the gridded weather product is indicated by the orange square. The data displayed will be the nearest match in time to the selection and the actual valid time of the data can be found in the lower-right corner of the primary display panel. When in doubt of the valid time, be certain to look here for the actual valid time of the displayed product(s). Users may click (using the left mouse button) and drag (while depressing the same mouse button) this orange square backwards or forwards to select a time in the past or future. The animation controls are relatively straight-forward. Click the play button to start animating and then click the same button to stop the animation. You can increase or decrease the speed of the loop as well as lengthen or shorten the amount of time spent on the final frame, referred to as dwell. Be aware that it takes the software some time to create the first loop of the animation so please be patient while all frames load; thereafter, the animation should run more quickly and smoothly. Maximum speed of the loop depends on many factors that the software developers cannot control like the speed of the computer and the load of the host computer due to various applications that are running on it.

GIS map characteristics

The Flight Path Tool application utilizes the Mapserver map service to provide the default map data to the application. At this time, most of the GIS data displayed has been pre-configured to show various data at specific resolutions and cannot be altered by users. A future version will allow users to configure these layers dynamically and add their own data (helicopter bases for example). At this time, the data available as users zoom into progressively smaller regions includes:

  • U.S. state borders (and state abbreviation labels)
  • Major rivers
  • U.S. county borders (and labeled names)
  • Interstate highways
  • U.S. and state highways
  • Major arterial streets
  • Airports (runways displayed)
  • Full street-level details will be available in the future

The default ArcIMS® map server may fail for slow internet connections so a small subset of these data are built into the application. If the web map server fails, the application will automatically switch to using the less sophisticated built-in maps.

Configuring specific weather overlays


METARs are observations of surface weather including temperature, winds, moisture, visibility, ceiling, present weather obstructions (like rain/snow/fog), altimeter setting and more. These are NWS textual messages in their original form. The current application conveys some of the most important aviation information as an icon for sky coverage and flight category (VFR,MVFR, IFR, LIFR) whereas the other parameters are available for viewing by the configuration dialog box.

By default, when the screen cursor passes over a reporting site, a text message appears on screen to reveal that station's ceiling and visibility observation along with the full original text. Furthermore, to prevent excessive clutter on the screen, only a minimal set of data are displayed for all sites. As soon as the user requests other data (temperature for instance), the tool will reduce the number of stations shown to keep from completely obscuring other stations' data. Zoom in and out operations will result in a de-clutter technique that may remove some sites and/or reveal others. If the reporting site you seek is not shown, either zoom closer to that site or use the configuration dialog box to enable more (or fewer) reporting sites.


TAFs are terminal aerodrome forecasts and represent forecasts of surface weather conditions expected in the next 24 hours at specified airports. Not all sites that report METARs have TAFs issued. The TAF configuration dialog box is not shown because there are no important configuration options for these data at this time. When the screen cursor appears over a TAF site, the full NWS text message should appear on the screen. This coded message is standard and not necessarily simple to decode by all users.


PIREPs are pilot reports of weather, clouds, icing, turbulence, and other phenomenon that are received by various FAA services like radio communications between the cockpit and ground controllers. A small fraction of these reports arrive via automated reporting systems. Similar to METARs, these data are represented in this application by icons (see figure below) for icing, turbulence, and cloud coverage. Placing the screen cursor over one of the icons produces the full text message as relayed by the NWS. Abbreviations found in these messages are standard practice and users are referred to the ADDS PIREPs Help pages. The altitudes displayed for PIREPs are above mean sea-level, not above ground level (unless specifically stated in the text, which is uncommon). Users can control the vertical altitude range of PIREPs that are displayed by using their mouse to drag either top and/or bottom orange rectangles in the configuration dialog box's

altitude slider bar. PIREPs either above the top or below the bottom of these orange rectangles are excluded from the display.


AIRMETs are NWS advisories for possible adverse weather conditions including icing, turbulence, IFR, and mountain obscuration. SIGMETs are significant weather advisories for known or forecast hazardous icing, advisory may be shown or hidden:

As mentioned in the Weather overlays section, activating certain gridded weather products automatically enables their corresponding advisory product(s) by default. If these items are not desired, they must be manually hidden from the display after each switch of the gridded weather product. AIRMETs are generally issued every 6 hours unless amendments are needed. Advisories are displayed in the tool within a few minutes of receipt by ADDS servers. As with other overlays, a small icon is placed at the center of this overlay product and when the screen cursor passes over this icon, the region covered by the AIRMETs is highlighted graphically and the full NWS text message is shown on the screen. A new feature found in this version is the border (dashed line) of any AIRMET or SIGMET will also trigger the pop up text and area highlight, partially transparent. Depending on the zoom level of the application, it can be difficult to see the full extent of this overlay product so users are advised to zoom out if the highlighted polygon isn’t fully apparent.