SkyDemon Plan Documentation: Route Analysis and Briefing

Back to Table of Contents

Enroute Features

As you planned a route you probably saw the powerful Enroute Features window at the bottom of the screen updating itself with a side-on view of your route, including all features likely to be of interest or relevant to your flight. This view gives you an instant impression of how your route relates to terrain elevation, all types of airspace, obstructions and lankmarks you will pass.

There are several places in SkyDemon where safety margins are used: calculation of your MSA for each leg, how much terrain to include in the Enroute Features window, how far vertically and abeam you wish to remain from fixed obstructions, for example. These variables can be modified in the MSA tab of the Preferences window, accessible from the Tools menu. As you plot a route, SkyDemon examines the terrain elevations for a certain distance abeam of your route (Horizontal Terrain Clearance) and ensures you are at least a certain distance (Vertical Terrain Clearance) above. This terrain profile is what is drawn in Enroute Features.

You can zoom in and out of the Enroute Features window by using the mouse wheel (after clicking in the window) or by using the zoom in and out buttons on the left of the window. Like the main map, you can click on an empty area and drag left and right to scroll the window when there is more detail than can be shown in one screen. Also like the main map, you can hover the mouse cursor above any feature displayed to read more information about it. Double-clicking in the enroute features window will pan the main map so that it shows that point.

Route Adjustment

The planned route is represented in Enroute Features by a thick magenta line, like it is on the main map. The line is given a red border if a leg is planned below its minimum safe altitude (MSA) and therefore needs to be raised. Each leg is separately selectable and can be dragged up and down to set its planned level. As you drag, a label lets you know the altitude to which you are dragging. This is a great visual way of dragging your route legs such that they avoid airspace or obstructions.

You can double-click a leg to open its properties window, allowing adjustment of the TAS, level and wind for that leg.

Weather in Enroute Features

Although weather briefing is covered later in this page, it is worth noting that as you plan a route, weather data is automatically downloaded from airfields close to your route (within 15 nm by default). Both TAFs and METARs are retrieved. This weather data is drawn graphically on top of the side-on view of your route. Weather data, when available, appears as a translucent column that can contain clouds and other features, but can also be clear, indicating good conditions.

Not all data contained in a weather report/forecast is drawn in the enroute features window. Included are cloud layers, rain, snow and visibility (including fog/mist). Having the cloud layers appear in the sky is a great way of instantly appreciating how they will relate to your route. Obviously, if your route appears to pass through cloud, it cannot be undertaken VFR. The screenshot on the right shows cumulonimbus forecast over Yeovilton.

You should always hover the mouse over weather information to bring up the full TAF or METAR, which will often include more detailed information than can be graphically depicted.

Weather Briefing

TAF and METAR are automatically retrieved for your route as you plot it, and as well as being decoded in their own separate windows, they are depicted in both the main map and the enroute features view. The buttons to control this are on the top toolbar; the TAF button is a cloud with a clock sitting on it, and the METAR button is a cloud with a pair of glasses sitting on it. You can switch between viewing TAF, or METAR, or neither (if they are obscuring something else on the map).

If you wish to see weather from stations that are not near to your route, simply right-click the airfield and select Get Weather. A list of airfields being monitored for weather data can be viewed by selecting Weather Stations from the Window menu. This window is not usually displayed but can also be used to add airfields from which to obtain weather briefings, and to view whether TAF or METAR data has been found for each registered airfield.

Weather bulletins (TAF and METAR) are represented on the main map as standard weather icons involving sunshine, cloud, rain etc. The wind is shown on top of the icon with the standard feathered representation. The icons are designed to depict conditions for VFR flight, so only consider an upper vertical limit of 5000 feet above aerodrome level. Thus a bulletin advising of an overcast at 6000 feet AAL will appear as clear sunshine.

Along with these weather icons on the main map you will sometimes see a large storm cloud covering the aerodrome; this appears when the bulletin is considered to represent bad weather for VFR flight. The thresholds for determining what constitutes bad weather are configured in the Weather tab of the Preferences window, since everyone has their own different safety limits. These clouds are a useful way of quickly determining whether a route is flyable according to your own standards: just load your route, and see if they appear.

The key to visualising weather information, besides that data which is depicted graphically in the maps, is the METAR Information and TAF Information windows. These are attached to the bottom of the main window.

Every METAR found is displayed in the METAR Information window. Most information contained within is decoded and displayed in plain English, with graphical depictions to further enhance clarity. Where it is determined that an item of information is likely to be detrimental to VFR flight, it is drawn in red and the entire METAR is given a red background to signify this. Because there are some items in a METAR that cannot be automatically decoded, you should always hover the mouse over a METAR to view the raw bulletin.

Every TAF found is displayed in the TAF Information window. Like with METARs, most information within each TAF is decoded and displayed with similar warnings where necessary. The only difference is that for each TAF there is often further information associated with forecast changes, so underneath the main TAF you may see that the weather is forecast to become different or is forecast with other temporary phenomena. In the image to the right, for example, the forecast for Plymouth has additional data whereby there is a 40% probability of lesser visibility and cumulonimbus activity. Again, you should always hover the mouse over a TAF to view the raw bulletin.

NOTAM Briefing

NOTAM are automatically downloaded from Eurocontrol for many FIRs in Europe as you plot your route. The areas for which we can automatically present NOTAM like this will expand over time.

To display NOTAM for a FIR for which we do not automatically obtain data, you will need to obtain them from an online briefing service. You then copy this data to your clipboard, and press the Paste button in the NOTAM window in SkyDemon to import them. When you press Paste a window is displayed showing what NOTAMs have been found in the clipboard. They are also drawn on the map so you can ascertain you are about to import the correct data. In this window there is a link which takes you to a list of online services where NOTAM data can be obtained.

NOTAM are depicted where possible on the main map usually as circles with a hatched magenta filling. The exceptions are very large NOTAM which are not drawn by default, and formation transit NOTAM which are depicted as a line connecting points. The outline of a NOTAM is colour-coded to give you a quick idea of what they concern:

As always, the mouse can be hovered over them wherever you see them to read their full text, their period of applicability and their vertical limits. Additionally you will see NOTAM in the Enroute Features window if your route passes them.

The depictions of NOTAM circles of influence on the SkyDemon main map are precise, but in some cases we do not draw them (because they are too big) or we interpret coordinates within, so that they are depicted as lines (for formation transits). The definitive list of NOTAM that apply to your route and that you need to read is displayed as a narrow route briefing in the NOTAM window.

NOTAM Filtering

NOTAM pass through several filters before they are displayed, because there are usually far more notices available than actually apply. To access the filtering applied, press the Filter button in the NOTAM window. The first filter is the period of validity, which by default covers a couple of days from when you opened SkyDemon, or the period of your flight, if you have specified a date and time for it. The next filter is the type of traffic concerned; this is normally just left as VFR.

The next filter switches between area brief, where all NOTAM within an FIR as shown, or narrow route brief, where only NOTAM near to your route are shown. In most cases a narrow route brief is required and the proximity values are configurable.

There is also a filter applied only to mapping: by default, all NOTAM with a radius greater than 15 nm are not drawn on the maps, with the exception of those activating a TRA. The reason for this is that there are often extremely large NOTAM designed to cover the entire FIR or significant parts of it, and if these were plotted on the map it would become a large purple blob and therefore unusable. They are therefore omitted from the maps but are still displayed in full detail in the NOTAM window. If you wish, you can change this radius threshold from the filtering window.

Next: Aircraft Management and Calculations