EZ-GPS v4 Users Guide

EZ-GPS V4 Features ........................................................................................................... 1 Map Page ............................................................................................................................. 2 Aviation Page ...................................................................................................................... 6 The OBS Feature ............................................................................................................. 8 Traffic Page ....................................................................................................................... 10 Find Feature....................................................................................................................... 11 Find By Nearest............................................................................................................. 11 Find By Identifier.......................................................................................................... 12 Routes And Waypoints...................................................................................................... 16 User Waypoints............................................................................................................. 16 Routes ............................................................................................................................ 19 Managing Waypoints .................................................................................................... 21 Airspaces ........................................................................................................................... 22 Menu Reference ................................................................................................................ 23 Routes ............................................................................................................................ 23 Load Route ................................................................................................................ 23 Show Route ............................................................................................................... 23 Save Route................................................................................................................. 23 Cancel Route ............................................................................................................. 24 Reverse Route ........................................................................................................... 24 AutoPilot.. ..................................................................................................................... 24 Autopilot Master ....................................................................................................... 24 GPS Route Hold ........................................................................................................ 24 GPS VNAV Hold ...................................................................................................... 25 Heading Hold ............................................................................................................ 25 Altitude Hold ............................................................................................................. 25 Approach Hold .......................................................................................................... 25 Airspaces ................................................................................................................... 25 Go To Cursor................................................................................................................. 25 Cancel OBS ................................................................................................................... 25 Sounds... ........................................................................................................................ 25 Map Settings.................................................................................................................. 26 Aviation Settings... ........................................................................................................ 27 Customize... ................................................................................................................... 28 GPS Status..................................................................................................................... 29 Software Version........................................................................................................... 29 Appendix A: Runway Approaches.................................................................................... 31 EZ-GPS V4 Guided Autopilot Approaches .................................................................. 32 Appendix B: Technical Reference .................................................................................... 33 AutoPilot ....................................................................................................................... 33 AutoSequence................................................................................................................ 33 Appendix C: Performance Tuning .................................................................................... 35

EZ-GPS v4 Features
The EZ-GPS v4 consists of a display screen and a keypad to control its operation. The display shows maps, aviation panels, menus, and information pages. The keypad is located below the display. The keys are used scroll the map or navigate through menu selections, decrease or increase the map scale (zoom in or zoom out), and to locate aviation features such as airports, VORs, NDBs, and intersections. The illustration below shows the map display page:

There are three main display pages: map, aviation, and traffic. Use the PAGES key to switch between them. The MENU key displays the main menu of EZ-GPS v4. Once in the menu system, pressing the MENU key again exits all menu levels immediately and returns to the main display page, bypassing the need for multiple presses of the EXIT key. When the map is d isplayed, the ZOUT and ZIN keys are used to change the map scale. The current map scale is shown in the lower left corner of the display. When the aviation page is displayed, these keys 1

change the range of the course deviation indicator (see the Aviation Page section later in the manual). In the traffic page, the ZOUT and ZIN keys change the scale of the range rings on the display.

In the center of the keypad are the cursor keys. These are used to scroll the cursor in the map display (see the Map Page section next in the manual). They are also used to navigate through the menus and to change values displayed with the menu commands. They are identified in this manual with the symbols: . The EXIT key is used to toggle the cursor on and off in the map page. In the menu system, the EXIT key returns to the previous menu level. The FIND key activates the Find feature described later in this manual. The ENT key is used to make menu selections and enter commands. Pressing the MSG button displays airspace alert messages. Airspace alerts are issued whenever you are approaching or entering controlled airspaces. The MSG button will flash red when an alert is issued. After you acknowledge the alert by displaying the message, the button will remain a steady red until the alert condition no longer exists. See the Airspaces section later in the manual for a discussion of airspace alert messages.

Map Page
The map is shown as the initial display page when the EZ-GPS V4 is turned on. It shows the aircraft position and, depending on the map scale, other nearby features such as lakes, rivers, roads, airports, and aids to navigation (VORs and NDBs). When navigating to a waypoint or following a route, the status display at the bottom of the map display shows the following indicators: BRG The magnetic bearing from the aircraft position to the waypoint. This is the heading required for the aircraft to fly directly to the waypoint. TRK The current magnetic track or heading of the aircraft. CDI Course Deviation Indicator. This is an indication of how far off the course line the aircraft is. See the Aviation Page section later in this manual.

Dest This is the identifier of the current waypoint. 2

The following illustration shows a typical status display on the map page when following a route:

The route itself is shown as a green line. The aircraft position remains fixed and the map scrolls as the aircraft progresses. The map is initially displayed with a North up orientation, but can be displayed with an aircraft heading up or track up orientation. Pressing the Menu key, choosing Map Settings from the menu and unchecking the Show North Up setting changes the orientation to heading up. Heading up is not available when the display is zoomed out to extreme ranges. The map has a cursor feature that is used to scroll the map and select features shown on the map. Pressing any cursor key or pressing the EXIT key enables the cursor. While the cursor is displayed, the status box at the bottom of the display changes to show the cursor position, bearing, and distance from the aircraft position. This display is shown in the next illustration:

The ZIN and ZOUT keys can be used change the map scale and center the map on the cursor position. Pressing the EXIT key returns the display to the aircraft position. After the cursor has been moved, entering cursor display mode with the EXIT key will move the map display to the last position of the cursor. If you wish to enter cursor display mode from the aircraft position, press any cursor key to enter cursor display mode rather than the EXIT key. You can obtain information about map features such as airports, VORs, NDBs, and intersections by moving the cursor over the feature and pressing the ENT key. If there is only one feature at the cursor an information screen will immediately appear. If there are multiple features at the cursor position, a window will appear listing the features. Use the and cursor keys to scroll to the feature you are interested in, press the ENT key and an information screen will appear.

You can set a waypoint at the feature by using the or cursor keys to scroll the menu at the bottom of the information display until the Create Waypoint menu choice is displayed. Press the ENT key and a waypoint will be created. Waypoints are described in the Routes and Waypoints section later in this manual. The airport information display consists of several pages identifying the runway system and any ILS approaches. It is described in the Find Feature section later in this manual. As you zoom the map out, the display of various map features is disabled to de-clutter the map. You can control what features are displayed and the scales they are displayed to with the Map Settings and Aviation Settings commands in the main menu. These commands are described in the Menu Reference section of this manual.

Aviation Page
The aviation page is used to aid in navigating to a waypoint or following a route. The page consists of a status displays, aircraft speed tape, aircraft altitude tape, a compass display, and a course deviation indicator.

The lower status display is the same as shown on the map page. When following a route or using the OBS feature (described later in this section) the CDI (course deviation indicator) indicates how far from the course line the aircraft is. If the indicator is to the right of center, the course line is to the right of center, and you must steer the aircraft to the right to regain the course line. When navigating to a single waypoint, the CDI indicates the difference between the bearing to the waypoint and the current track. The range is 45 to +45. The upper status display has the following elements: Dist The distance from the aircraft position to the next waypoint. 6

ETE

The Estimated Time Enroute to the next waypoint.

CRS The course line from the previous waypoint to the next waypoint. When the OBS feature is active, the name of this box changes to OBS . XTR The cross track ranges in nautical miles of the CDI in the lower status box and of the CDI indicator in the compass display. Use the ZIN and ZOUT keys to change the cross track range. The main feature of the aviation display is the compass. The aircraft track or heading is always towards the indicator at the top of the compass. The arrow points towards the waypoint. Deviation from the course line is shown with the course deviation indicator, depicted as a red line, offset to either side of the arrow. If the course deviation indicator is to the right of center, the course line is to the right of center, and you must steer the aircraft to the right to regain the course line.

The small indicator lines parallel to the waypoint arrow show how far you are from the course line. The distance between the outermost lines is shown in nautical miles in the upper status display in the XTR (cross track range) box. Use the ZIN and ZOUT keys to change the cross track range. Note: the cross track range affects the course deviation indicator in the compass and in the lower status display. The autopilot-heading bug is shown just outside of the compass circle.

The OBS Feature

The OBS feature can be used whether you are following a route or navigating towards a single waypoint. This is a useful feature when it is required that you fly a specific course to (or from) a waypoint. While the course is usually a VOR radial, the OBS feature can be used with any waypoint. To activate the OBS feature, press either the or the cursor key. A dialog box will appear asking to confirm OBS activation.

Press the ENT key to activate the OBS. Use the or cursor keys to change the selection from Yes to No. After the OBS is activated, an additional pointer is displayed on the waypoint arrow. Because the waypoint arrow always points towards the waypoint, the second arrow indicates whether you are flying towards or away from waypoint. Use the and cursor keys to change the radial to (or from) the waypoint.

In the illustration above, you are flying away from the VOR (PSI) on a radial of 104. The course deviation indicator shows that you are approximately 1.5 nm from the radial (the XTR setting is 4.00 nm, so each course deviation indicator line represents 1.0 nm). The OBS feature is manually cancelled by choosing the Cancel OBS command from the main menu. It is automatically cancelled if you reach the waypoint or are following a route and the route sequences to the next waypoint.

The map page shows the OBS radial as an orange line as depicted in the following illustration.

Traffic Page
This page is used to display the relative horizontal positions of nearby aircraft traffic. The display is always shown with the heading of your aircraft towards the top of the display: heading up. Two range rings help in judging how far the traffic is from your aircraft. The radius of the outer range ring is shown in the lower left corner of this display. The range can be increased or decreased with the ZOUT and ZIN keys respectively. Nearby traffic is displayed with one of the following symbols:

Normal Traffic Proximate Traffic Threat Advisory Resolution Advisory A typical traffic page appears as shown in the following illustration:

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If the traffic is above your altitude, the altitude difference in hundreds of feet will be shown above the symbol with a plus sign. If the traffic is below your altitude, the altitude difference in hundreds of feet will be shown below the symbol with a minus sign. If the traffic is changing altitude at a rate of more than 600 feet per minute, an arrow will be shown to the right of the symbol, pointing in the direction of the altitude change.

Find Feature
The Find feature is activated with the FIND key. It can be used to find and display information about airports, VORs, NDBs, and intersections. You can locate features by identifier or by choosing from a list of nearby features. Once a feature is identified, you can show it on the map or set a waypoint at it.

Find By Nearest
Press the FIND key and choose the type of feature you are interested in from the menu by using the or cursor keys. Press the ENT key and a popup menu will appear with the choices By Identifier and By Nearest . Scroll to By Nearest and press the ENT key. The display will show a list of the nearest features; either airports, VORs, NDBs, or intersections. Use the or cursor keys to scroll through the list. Press the ENT key when your choice is highlighted and an information page about the feature will be displayed. Using the or cursor keys you can choose to show the feature on the map or set a waypoint at it.

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Note

If the map page is displayed and cursor mode is on (the cursor is displayed), the find by nearest display shows a list of features nearest to the cursor position. Otherwise, the find by nearest display shows a list of features nearest to your aircrafts position.

Find By Identifier
The find By Identifier display consists of two elements: an ID entry box and a list of identifiers that match the characters entered. In the ID entry box, use the and cursor keys to scroll through letters and numbers. Use the and cursor keys to scroll through the character positions. In the following example you will locate the airport KJFK. First, open the find By Identifier display by pressing the FIND key. Next, choose Find Airports and then By Identifier from the menus. Using the cursor key, scroll the first character position to K. Press the cursor key once to move to the second character position and then use the cursor key to scroll to the character J. The display will appear as shown in the following illustration:

The airport that we are interested in, Kennedy Intl, has appeared in the display. Use the ENT key to switch from the ID entry box to the list of airports. Then use the and cursor keys to scroll through the list. Use the EXIT key to switch back to the ID entry box.

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Once the desired feature has been highlighted, use to ENT key to display the information page for it.

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The airport information display consists of four tabbed pages. Use the PAGES key to cycle through the pages. The first page contains information about the airport in general and its tab is labeled with the airport identifier. At the bottom of each page is a menu that gives you the choice of showing the airport on the map or setting a waypoint at the airport or a specific runway. Use the and cursor keys to scroll through these menu choices. The second page, labeled Plan, shows a diagram plan of the airport runway system.

Waypoints can set for individual runways. The current runway is highlighted in blue and the selected approach is identified in red, both on the runway itself and in the runway identifier listed in upper left corner of the display. Use the and cursor keys to scroll through the runways. The EZ-GPS V4 can provide autopilot guidance for a runway approach. See the Autopilot section later in this manual and the Runway Approaches appendix at the end of this manual.

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The third page, labeled Rwy details the airport runways.

The last page shows any ILS approaches available at the airport.

The ILS page of the airport information display has the option to show an additional display about the selected ILS. The next illustration shows the ILS information display.

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A waypoint can be set on an ILS approach. If the current waypoint is an ILS approach and GPS route hold is enabled, the EZ-GPS V4 will tune the NAV1 radio and turn autopilot guidance over to the autopilot approach hold function. See the Autopilot section later in this manual.

Routes And Waypoints

A waypoint is a feature such as a VOR, NDB, or intersection that you choose as a point to navigate your aircraft towards. A route is a series of waypoints, each waypoint representing a leg of the route. As you create waypoints, they are connected together in the order that you add them to create a route. It is also possible to insert a waypoint into a route as described later in this section. Waypoints can be established in a number of ways. You can use the FIND key to identify a feature and then choose Create Waypoint on its information page. You can scroll the cursor on the map display to a feature, display its information page by pressing the ENT key, and create a waypoint.

User Waypoints
These methods create waypoints from established navigation features. You can also create your own waypoints anywhere on the map. Simply scroll the cursor to where you want to create a waypoint and press the ENT key. If no feature is displayed at that location, the Create Waypoint menu will appear.

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The first menu choice will create a waypoint at the cursor position. Press the ENT key, the waypoint will be established, and a waypoint information page will be displayed as shown in the following illustration.

You can create a waypoint at a specific latitude and longitude position w ith the second menu selection in the Create Waypoint menu: Entered Position. This selection will display the Enter Position screen allowing you to enter the coordinates of the waypoint.

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Use the and scroll keys to choose from Latitude , Longitude , and Ok. When either Latitude or Longitude is highlighted, press the ENT key to enter edit mode and establish a value for that item. While editing, use the and scroll keys to change values and use the and scroll keys to between character position. Once you are satisfied with the value, press either the ENT key or the EXIT key to leave edit mode. To create the waypoint, scroll to the Ok button and press ENT the key. The waypoint information page will be displayed.

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You can also create a waypoint to a projected position. Choose Projected Position from the Create Waypoint menu to display the Project Waypoint screen.

This screen allows you enter a distance and course from your current position to create a waypoint. The values are entered as described above for the Enter Position screen.

Routes
A route is a series of waypoints that represent the legs of the route. A route can be developed by creating a series of waypoints as described above. You can also load a route from previously saved routes or flight plans. To load a previously saved route, press the MENU key, choose Routes from the main menu, and select the Load Route command from the Routes menu. A list of previously saved routes will be displayed. Note It may take a moment or two before the list is displayed while it is being loaded from secondary storage.

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Additional information about the selected route can be obtained by changing the menu selection at the bottom of the screen to Show Route Info with the and scroll keys.

Activate the selected route by pressing the ENT key when the Activate Route choice is shown.

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Managing Waypoints
Once a route has been created or loaded, you can manage the waypoints with the Current Route screen. Access this screen by pressing the MENU key, choose Routes from the main menu, and select the Show Route command from the Routes menu.

The current waypoint is shown in blue. Waypoints that have been passed are shown in grey. Waypoints that have not been reached are shown in black. The horizontal scroll menu at the bottom of the screen has the following commands: Activate Waypoint makes the selected waypoint the current waypoint Delete Waypoint deletes the selected waypoint. If it was the current waypoint, the next waypoint (if any) becomes the current waypoint. Waypoint Info displays the waypoint information page. Show On Map scrolls the map to the selected waypoint. The waypoint is centered in the display.

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Insert Waypoint inserts a waypoint after the selected waypoint. The inserted waypoint is placed at the position of the cursor on the map. If the cursor is positioned over a feature such as a VOR or intersection, the feature is used as the waypoint. If the cursor is not positioned over a displayed feature, a user waypoint is created.

Airspaces
Class B, Class C, and SUA airspaces are normally displayed on the map. You can add Class D and Class E airspaces or turn the display of airspaces off completely with the Aviation Settings command on the main menu (see Menu Reference later in the manual). Approaching or entering Class B, Class C, and certain SUA airspaces will trigger an airspace alert. An alert is issued when you are less than 10 minutes from a controlled airspace and a new alert for the same airspace will be issued once you enter it. A flashing MSG button indicates an airspace alert. The MSG button will remain flashing until you acknowledge the alert by pressing the button and displaying the alert message.

Dismiss the alert by pressing the MSG button again or by pressing the EXIT button. The MSG button will remain lit, but not flashing, until the condition that caused the alert no longer exists. Note If you are approaching or inside an airspace, but are above it, an alert will not be issued

Whenever you are approaching a controlled airspace or inside or above any airspace, the Airspaces command on the main menu will be available.

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The Airspaces command is used to display information pages for airspaces. A page is available for each airspace that you are approaching or inside. The current page number and the total number of pages are displayed in the upper right corner of the information page. Use the PAGE key to switch between pages.

Menu Reference
This section of the manual describes the main menu and its commands. The main menu is accessed with the MENU key.

Routes
The Routes command displays a secondary menu of commands for managing routes. The secondary menu commands are described below.

Load Route
This command is used to load previously saved routes and flight plans as described in the Routes And Waypoints section of this manual.

Show Route
Once a route has been loaded, use this command to display and manage the waypoints of the route as described in the earlier section Managing Waypoints.

Save Route
The Save Route command is used to save the current route to secondary storage. Saved routes can be reloaded at a later time with the Load Route command.

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Cancel Route
Use the Cancel Route command to cancel the current route, whether a single waypoint or a series of waypoints.

Reverse Route
This command reverses the order of the waypoints in a route.

AutoPilot..
The EZ-GPS V4 does not include an autopilot, but it can be used to control the autopilot of the aircraft. Select the Autopilot command in the main menu to display the autopilot control panel.

Use the and cursor keys to scroll through the control panel commands. Use the ENT key to turn on or off a specific autopilot command. To change the values in the Heading and Altitude boxes, press the ENT key when the command is highlighted and then use the scroll keys to increase or decrease digits and to move between digit positions.

Autopilot Master
Use this command to turn the aircraft autopilot on or off.

GPS Route Hold

The GPS Route Hold command directs the autopilot to follow the current route by controlling the autopilot heading. It will hold the aircraft close to the course line and automatically sequence from waypoint to waypoint. You can control the sensitivity of this command on the Customize control panel described later in this section. When GPS Route Hold is enabled, the Dest box in the lower status display will flash as you approach the transition from the current waypoint to the next waypoint. Enabling this command automatically turns the Autopilot Master and Heading Hold functions on.

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GPS VNAV Hold

This command controls the vertical navigation hold function of the GPS. VNAV is only available when the current waypoint is a runway approach. See the appendix Runway Approaches for a description of using this feature.

Heading Hold
This command controls the heading hold function of the autopilot. The heading bug can be set by changing the value in the Heading box.

Altitude Hold
This command controls the altitude hold function of the autopilot. The desired altitude can be set by changing the value in the Altitude box.

Approach Hold
Use this command to control the approach hold function of the autopilot. This feature is only enabled when the current waypoint is set to an ILS approach. Enabling this command will automatically tune the aircraft NAV1 radio to the ILS approach frequency.

Airspaces
The Airspaces command displays information pages about any airspace that you are approaching or inside of. See the Airspaces section of this manual for more information.

Go To Cursor
This command directs you immediately to the position of the cursor on the map. If a route is active, you will first be asked to confirm cancellation of the route.

Cancel OBS
This command cancels the OBS feature of the aviation display. See The OBS Feature section of this manual for details.

Sounds...
This menu selection brings up the Sounds control panel. This panel allows you to control what sound is associated with key presses, the volume of the sound, and whether any sound is made at all.

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Map Settings...
The Map Settings command allows you to control various features that are displayed on the map including lakes, rivers, roads, compass overlay, and range rings. This command also allows you to control whether the map is shown with a North up orientation or a heading up orientation.

Use the and scroll keys to select the feature and then press the ENT key to turn the feature on or off. The menu at the bottom of the screen contains two commands: Show/Hide On Map and Map Scale Setting (for Waterways and Roads only). The Map Scale Setting allows you to control the maximum map scale at which the feature will appear.

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Aviation Settings...
This command allows you to control various aviations features that are displayed on the map including airports, approaches, VORs, NDBs, and Intersections.

Use the and scroll keys to select the feature and then press the ENT key to turn the feature on or off. The menu at the bottom of the screen contains two commands: Show/Hide On Map and Map Scale Setting. The Map Scale Setting allows you to control the maximum map scale at which the feature will appear. Additionally you can limit the display of airports to just those with runways longer than a specified minimum.

The map scale setting for airspaces contains additional check boxes for specifying the types of airspaces you want displayed on the map. 27

Customize...
The Customize command allows you to control several aspects of the display and operation of the EZGPS V4.

The Transparency slider control is used to adjust the amount of transparency in menus and control panels that are displayed on top of the map or aviation screen. Use the Refresh slider to control how often the map display is updated. See the Performance Tuning Appendix for a discussion of using this control. The AutoPilot slider controls the sensitivity of the GPS route hold function of the autopilot. L ow settings will allow the aircraft to drift further from the course line before a course correction is made. High settings will hold the aircraft closer to the course line, but may require more frequent course corrections.

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The AutoSequence slider primarily controls bank angle used for calculating when to begin the turn when transitioning from waypoint to waypoint. See the Technical Reference Appendix at the end of this manual for a discussion of the autosequence function of the EZ-GPS V4.

GPS Status
This command displays a view of satellites that the EZ-GPS V4 is receiving and their signal strengths. It also displays the time, date, your position, altitude above sea level, and altitude above ground level.

Software Version
Use this command to display the software version of the EZ-GPS V4 and an indication of current memory usage. The number of maps loaded and how much memory they require is dependent on scale setting in the map display. As the display is zoomed out, more maps are needed to fill the display.

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Appendix A: Runway Approaches

The EZ-GPS V4 has the capability to guide you through a runway approach. You can even direct the EZ-GPS V4 to control the autopilot for a runway approach. The first step is to select the runway you want guidance for. To select the runway, open an airport information display, either by using the Find feature to specify the airport, or by scrolling to its symbol on the map and pressing the ENT key. Once the airport information is displayed, use the PAGES key to select either the Plan tab or the Rwy tab. Using the and scroll keys, scroll to the runway that you want guidance for. Use the or scroll keys to select the Create Waypoint choice and press the ENT key. If you are not following a route or there are no waypoints, the runway will become the current waypoint. If you are following a route, use the Show Route page to activate the runway waypoint (see Managing Routes in the Routes and Waypoints section). When a runway (or an ILS) is the active waypoint, the aviation page will display an additional indicator on the altitude tape to identify the altitude required to maintain the glide slope. The glide slope indicator appears as a red arrow pointing to the required altitude. When the aircraft is within 5 feet of the required altitude, the indicator color will change to blue.

In the figure above, the aircraft altitude is 1450 feet and the glide slope altitude is 1550 feet: the aircraft is 100 feet below the glide slope and should decrease its rate of descent. Note that the Dest box in the status display contains the runway identifier. The glide slope altitude indicator and the CDI will give accurate representations of deviations from both the horizontal and vertical approach paths.

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If an ILS approach with a glide slope is available for the runway, the EZ-GPS V4 will use it to determine the glide slope angle and the touchdown point. If an ILS approach is not available, the glide slope is set at 3 and the touchdown point is set at 150 feet from the runway end. CAUTION The EZ-GPS V4 does not account for displaced thresholds or runway extensions.

GPS Guided Autopilot Approaches

The EZ-GPS V4 can supply both HNAV and VNAV autopilot guidance for runway approaches. The aircraft must be approximately lined up with the runway before initiating EZ-GPS V4 autopilot guidance. To initiate HNAV guidance, select GPS Route Hold from the autopilot control panel in the main menu. To initiate VNAV guidance, select GPS VNAV Hold from the autopilot control panel. Selecting GPS VNAV Hold first will automatically enable GPS Route Hold. CAUTION The autopilot may not be able to respond to EZ-GPS V4 commands as quickly as necessary to maintain the course line or glide slope. Be prepared to disengage the autopilot if it becomes apparent that necessary corrections cannot be made automatically. When the altitude above ground reaches 200 feet, the autopilot is automatically disengaged and manual control of the aircraft is returned to the pilot. NOTE For EZ-GPS V4 guided autopilot approaches, the gyro compass must be adjusted exactly. Press the D key to adjust the gyro compass.

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Appendix B: Technical Reference

This section describes underlying logic of several of the EZ-GPS V4 autopilot features. An understanding of these features is helpful to obtain the most effective use of them.

AutoPilot
The autopilot heading hold function can maintain integral degree course headings. However, the course line from waypoint to waypoint is rarely an integral degree value. If the difference between the course line and the autopilot heading is 0.5, an aircraft flying at 120 knots will be mile off course in 15 minutes. An aircraft flying at 180 knots will be mile off course in 10 minutes and an aircraft flying at 300 knots will be mile off course in 6 minutes. Crosswinds can increase this distance. Therefore, the EZ-GPS V4 must make continuous small course changes to hold the required course line. The EZ-GPS V4 initiates a course correction based on how many seconds the aircraft is from the course line. If the aircraft is more than 60 seconds from the course line, the EZ-GPS V4 will fly to the course line at a 90 angle. As the aircraft nears the course line, shallower course corrections are made. The AutoPilot slider of the Customize command in the main menu controls the sensitivity of the EZ-GPS V4 route hold function of the autopilot. Low settings will allow the aircraft to drift further from the course line and make more gradual course corrections. High settings will hold the aircraft closer to the course line but may require more severe and more frequent course corrections.

AutoSequence
Autosequencing is the automatic transitioning by the EZ-GPS V4 from waypoint to waypoint as legs of the route are completed. If the EZ-GPS V4 is perfectly adjusted to the aircraft autopilot, the transition will end with the aircraft exactly aligned with the new course line. The EZ-GPS V4 needs adjustment if the aircraft consistently undershoots or overshoots the new course line, requiring excessive course corrections to obtain the new course line. The responsiveness of the autopilot to heading changes affects when the EZ-GPS V4 will initiate those requests. The turn radius of any aircraft is determined by: v2 g x tan b where v is velocity, g is gravity, and b is bank angle. Note that the turn radius is independent of aircraft mass. When the radius of the arc that connects the current course line to new course line equals the turn radius of the aircraft at its current speed, the EZ-GPS V4 initiates the course change. Velocity is the current speed of the aircraft. Gravity is set to be 1.1 x 32.174. Bank angle is initially set to 15. If the autopilot changes heading at a larger bank angle, the aircraft will undershoot the new course line, completing the course change earlier the EZ-GPS V4 calculated that it would. If the autopilot changes heading at a smaller bank angle, it will complete the course change later than the EZ-GPS V4 calculated that it would, and the aircraft will overshoot the new course line. The AutoSequence slider of the Customize command in the main menu can be used to change the bank angle used in the above calculation. T he range of the slider is 5 to 30 in 1 steps. Move the slider to 33

the right to adjust for more aggressive turns by the autopilot. Move the slider to the left to adjust for less aggressive turns by the autopilot. Note This adjustment does not adjust the autopilot itself, only how the EZ-GPS V4 will anticipate it.

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Appendix C: Performance Tuning

When the map is displayed, the EZ-GPS V4 makes hundreds of thousands of calculations each time it updates the map. If you notice that the EZ-GPS V4 is negatively impacting the frame rate of the flight simulator, there are several measures you can take to reduce the impact. The two greatest factors are map refresh rate and heading or track up display. When heading up display is selected (as opposed to North Up), many additional calculations are required to rotate the map and the display elements. If you notice that your frame rate decreases significantly with a heading up map orientation, change to a north up orientation for greater performance. The map is updated at a maximum of approximately 3 times per second. This rate can be reduced with the Refresh slider which is found in the Customize choice of the main menu. Move the slider towards Low to reduce the refresh rate. The effects of deducing the refresh rate are most noticeable when the map scale is set very low where the map may not scroll smoothly. Reducing the number of elements displayed on the map can improve frame rate. Road labels are a good first candidate to turn off. The map is divided into 288 sections. Some sections are very dense while others (oceans) contain little, if any, information. When the map is zoomed in, very few maps need to be loaded and displayed. However, as the map is zoomed out more maps are loaded and more features must be displayed.

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Activate Waypoint, 23 airport information display, 5, 15, 35 airspace alert, 24 airspaces, 2, 24, 28, 32 Airspaces command, 25 autopilot, 16, 18, 27 course deviation indicator, 2, 6, 7 cross track range, 7, 8 cursor, 4 cursor keys, 2 Delete Waypoint, 23 Find, 13 GPS VNAV Hold , 36 heading bug, 8 heading up orientation, 3, 30

ILS information display, 18 Insert Waypoint, 25 MSG button, 2 North up orientation, 3, 30 OBS feature, 8, 28 position, 33 route, 18 runway approach, 28, 35 runway approaches, 16 Show On Map, 24 user waypoints, 19 VNAV guidance, 36 waypoint, 5, 18 Waypoint Info, 23

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