SkyDemon Plan Documentation: Route Analysis and Briefing

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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. It also shows how your climbs and descents will look, given the performance characteristics of the selected aircraft and the requested levels.

There are several places in SkyDemon where safety margins are used: calculation of your MSA for each leg and how far vertically and abeam you wish to remain from fixed obstructions, for example. These margins can be modified in the Safety tab of the Planning Options window, accessible from the Setup menu. As you plot a route, SkyDemon examines the terrain elevations for a certain distance abeam of your route (Abeam 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, only it includes climbs and descents. The line is given a red border if the leg is planned below its minimum safe altitude (MSA) and therefore needs to be raised. Legs can be dragged up and down to change their planned level, as discussed previously. You can double-click a leg to open its properties window, allowing inspection of its properties and adjustment of level and cruise profile for that portion of the flight.

TAF and METAR in Enroute Features

Although weather briefing is covered later on, it is worth noting that TAF and METAR are automatically downloaded along your route and overlaid in the Enroute Features window. They appear as a translucent column that can contain clouds and other features, but can also be clear, indicating good conditions. Use the TAF and METAR buttons in the weather toolbar to control which, if any, are shown.

Not all data contained in a TAF or METAR 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 may not be possible to fly 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.

Winds Aloft in Enroute Features

Again, winds aloft are covered in detail later on, but you will see them represented in the Enroute Features window as arrows that go with your route (tailwind) or against your route (headwind) and whose thickness varies with the wind strength. This makes it easy to tell at a glance what sort of wind will affect your flight, and if there's anything to be gained by changing to a different level where the wind might be more favourable.

TAF and METAR Briefing

TAF and METAR are automatically retrieved for your route as you plot it, and are shown decoded in their own separate windows that can be accessed by clicking on "TAF Decode" or "METAR Decode" at the bottom of the screen. In addition, they are depicted in both the main map and in enroute features (as described above). Use the TAF and METAR buttons on the weather toolbar to turn these depictions on and off.

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 Planning Options window, since everyone has their own different 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 the clouds appear.

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

Every METAR found is displayed in the METAR Decode 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 Decode 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.

Weather Briefing

SkyDemon also includes weather forecast data which is automatically downloaded for the area of your route, and this extends to 15,000 feet and 24 hours ahead. As you plotted a route you may have noticed wind feathers appearing on the main map at regular intervals and tailwind/headwind indicators in the background of the Enroute Features window. If you don't see these, ensure that the Wind button on the weather toolbar is checked.

The date and time represented by the wind feathers, and the level, defaults to the date, time and level of your flight, as set in the Flight Details window. You can change this though, to explore how the wind will change over time and at different levels. To do this, switch to the Weather window by choosing Weather from the Window menu.

The Weather window contains two sliders: the one on the left controls the time for which weather is being displayed. Drag the slider up and down to observe the change in wind over time. It may take a few seconds for wind to appear once you have changed the slider significantly, as new data has to be downloaded. Once data is downloaded (the slider lights up when this has happened) you can smoothly scroll it up and down, or use the mouse wheel. The slider on the right sets the altitude for which winds are being displayed, which can be set between 1,000 and 15,000 feet. This applies to the wind representations on the main map; the Enroute Features window always shows the wind at all available altitudes.

NOTAM Briefing

NOTAM are automatically downloaded from Eurocontrol for many flight information regions 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. You should always read this briefing.

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.

Weight and Balance Calculations

The Weight & Balance window is next to the NOTAMs window. It consists of a list of aircraft loading points in the upper half, and a graph of the loading envelope below, with the results of current calculations plotted on it. The loading points are defined once in aircraft properties, and are simply filled in, in this window, when you plan a route. The value for fuel is automatically filled in as a result of the fuel calculations done in the Flight Details window.

Each loading point has a weight value. This is a hyperlink and can be clicked to change it. For instance, you will see an entry for the Pilot; click where it says 0 kg and enter the actual weight of the pilot. Press enter to confirm and you will see the graph update. All the values apart from Fuel need to be entered manually. The Fuel value can also be adjusted manually if you wish, but it will be overwritten when the fuel plan is next updated.

On the graph is drawn a thick orange line, with a solid green bar at one end denoting the full fuel weight and an empty red bar at the other denoting the empty fuel weight. On this line are plotted a black X which reflects your takeoff weight and a gray X which reflects your landing weight. It is of course important to ensure that both takeoff and landing weight are within limits on the graph. The graph will turn red if this is not so.

Planning Warnings and Prompts

If any part of your planned route or aircraft configuration is considered unsafe or worthy of attention, a warning will appear in the Flight Details window telling you about it. Additionally, there are some helpful prompts that appear when certain conditions are detected and are designed as reminders rather than warnings. Warnings are red, and prompts are golden in colour.

Warnings

• Penetration of Class A Airspace
  If any part of your route passes through Class A airspace this will generate a warning since VFR flight is not normally allowed in such airspace. Clicking on the warning will take you to the piece of airspace concerned.
• Penetration of Dangerous Airspace
  If any part of your route passes through a danger, restricted or prohibited area this will generate a warning for each occurrence. Clicking on the warning will take you to the piece of airspace concerned.
• Fuel Problems
  If you have not planned to carry enough fuel, or your journey requires more fuel than the aircraft can actually carry, this warning is shown.
• Minimum Safe Altitude
  If any leg of your journey is planned at a level below the MSA for that leg, this will generate a warning. Clicking on the warning prompts to increase the planned level of the leg so that it is safe.
• Penetration of NOTAMed Airspace
  If your route passes through a temporary restricted area established by NOTAM, this will generate a warning. Clicking on the warning will take you to the NOTAM concerned.
• Charts out of Date
  This warning will appear upon starting the software and indicates that at least one of your charts is out of date. Because our charts are updated every 28 days (a good thing) this warning will appear about as often. Simply click on it to show the Charts window, then press Apply Changes to have SkyDemon automatically update all your charts.

Prompts

• Atmospheric Data Unavailable
  If some of the forecast conditions for your route are not available (usually winds aloft) a prompt is displayed to ensure you are aware that the conditions have not been factored into the flight model.
• Flightplan Filing Necessary
  If your route passes an international boundary it is likely that a flightplan will need to be filed, so a prompt is displayed. Clicking on the prompt brings up the File Flightplan window so that you can file a plan.

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