SkyDemon Mobile Documentation: Warnings and Navigation Aids
SkyDemon looks after you during flight by constantly monitoring your position and trajectory ahead, looking for potential hazards. Anything that could cause a problem to the flight is displayed as a warning, with prominent notification onscreen and an audible alert emitted too.
To change the settings for which warnings are displayed and their thresholds, select Warnings from the Settings menu.
Airspace Warnings
Airspace warnings are shown when your trajectory, both horizontal and vertical, would take you into a piece of airspace. An onscreen warning is accompanied by an audible alert, the form of which depends on the type of airspace, and a thick border is drawn on the map so you can clearly see which piece of airspace is associated with the warning. In the figure on the right, the Bournemouth CTR has been detected and a yellow warning displayed, complete with a thick yellow border around the airspace itself. The following table lists the types of airspace for which warnings are shown:
| Airspace Type | Warnings Shown | Warning Colour |
|---|---|---|
| Prohibited Areas Restricted Areas Danger Areas |
Yes | Red |
| Controlled Airspace (A) | Yes | Red |
| Controlled Airspace (B, C, D) | Yes | Yellow |
| Sporting Areas | Yes | Gray |
| NOTAM | Yes | Purple |
| Controlled Airspace (E, F) | Optional | Yellow |
| MATZ ATZ |
Optional | Blue |
When a warning is shown, it will stay onscreen until either it is dismissed or it is no longer applicable. The warning contains the name of the airspace, its distance ahead and, where possible, a radio station to contact to obtain clearance or information. Airspace warnings have two buttons: the one on the left, with a question mark, displays further information about the airspace such as its vertical limits and hours of activity. The one on the right, with a cross, dismisses the warning. When dismissed, no further warnings about that piece of airspace will be displayed for five minutes. If after five minutes the airspace is still approaching, the warning will be re-displayed.
Airspace warnings can optionally be suppressed while you are adhering to your planned route. To enable this, check the "No warnings when flying course" option.
Obstruction Warnings
Obstruction warnings are displayed when your trajectory, both horizontal and vertical, would take you within predefined limits of a fixed ground-based obstacle such as an antenna. An onscreen warning is accompanied by an audible alert. In the figure on the right, the aircraft is clearly at risk from the large antenna ahead of it.
When a warning is shown, it will stay onscreen until either it is dismissed or it is no longer applicable. The warning contains the type of obstruction, its distance ahead and advistory action to climb above it, based on the the configured vertical proximity threshold. Obstruction warnings have two buttons: the one on the left, with a question mark, displays further information about the obstruction such as its location and height. The one on the right, with a cross, dismisses the warning. When dismissed, no further warnings about that obstruction will be displayed for five minutes. If after five minutes the obstruction is still a threat, the warning will be re-displayed.
The vertical and abeam proximity that is acceptable for obstructions is configurable. The default abeam proximity is 4 nautical miles and vertical proximity is 1000 feet.
Off-Course Warnings
If you should drift off your planned route by more than 3 nautical miles, a warning is displayed until it is either dismissed or your course is adjusted such that you are again converging on your next waypoint. In the figure on the right, the aircraft has clearly diverged from its course towards Bishops Lydeard and a warning has therefore appeared onscreen. The course correction indicator is also advising a turn to the right of 40 degrees.
Off-Course warnings can be dismissed and, like the other types of warning, will not appear for five minutes after dismissal.
Airspace Notifications
Not to be confused with warnings, a notification is displayed whenever you enter or exit a piece of airspace. This is handy when ATC have asked you to advise them when you have entered or exited a zone.
When the aircraft is inside a piece of airspace, both laterally and vertically, a thick white highlight is drawn on top of the airspace border until you are no longer inside the airspace.
Extended Runway Centrelines
As you approach an airfield that is part of your planned route, its runways are examined to determine which would be most appropriate for landing based on your current position. An extended centreline is then drawn on the main map to facilitate lining up as early as possible. If your position changes and a different runway becomes most appropriate, the display will instantly change to reflect this.
The extended centrelines are drawn black if they are absolutely precise (the runway threshold is known) or gray if they are approximate (only the position of the airfield is known). Either is fine for a visual approach.
When you are lined up along the extended centreline and flying towards the runway threshold, you will also see glideslope information depicted in the virtual radar instrument. By aligning yourself and your vertical trajectory along this glideslope you can establish yourself on a stable approach early.
Plotting of extended runway centrelines can be disabled in Preferences, under the Navigation section. This is also where the glideslope angle can be changed; 3.0 degrees is the default.
