Update help and readme

There is one problem, that on touch down the plane is going underground on the short while.

CHANGELOG.md

@@ -1,5 +1,13 @@
 # CHANGELOG
 
+## v.1.8.1
+
+- Improve the approach to landing
+
+## v.1.8.0
+
+- The tow plane, after completing its route, returns to the runway from which it took off. For a bush take-off it does not land.
+
 ## v.1.7.0
 
 - Add possibility to set max altitude in route dialog

README.md

@@ -22,13 +22,13 @@ Where `{username}` is the name of the user logged into the operating system.
 
 Start FlightGear at any airport with your aircraft as a glider, such as ASK 21.
 
-From the top menu, select `Aerotow Everywhere` -> `Call for Piper J3 Cub aircraft`, `Robin DR400` or `Cessna 182` (yes, you can choose from many aircrafts). The AI aircraft will appear to your right and align to the centreline of the runway in front of you. At this time you should hook up to the aircraft, most often by pressing the `Ctrl-o` key (check help of your glider). The AI aircraft will begin to accelerate and take off.
+From the top menu, select `Aerotow Everywhere` -> `Call for Piper J3 Cub aircraft`, `Robin DR400`,  `Cessna 182` or `Douglas C-47`. (Yes, you can choose from many aircrafts). The AI aircraft will appear to your right and align to the centreline of the runway in front of you. At this time you should hook up to the aircraft, most often by pressing the `Ctrl-o` key (check help of your glider). The AI aircraft will begin to accelerate and take off.
 
 You can also take off in the bush. Then the tow plane will position itself in front of you (glider's course), so what heading you have is important. If you move away from the runway threshold further than 100 m, then the take-off of the tow plane will be as in the bush, i.e. according to the glider heading and not the runway.
 
 ## How does the AI tow aircraft fly by default?
 
-The tow plane always takes off in front of your runway and flies along the runway for 5 km, then turns back and flies downwind for 6 km, then turns back again and flies another 6 km. During this flight it is constantly gaining altitude. Then when it has completed the entire set route it turns to unknown direction and flies at a constant altitude.
+The tow plane always takes off in front of your runway and flies along the runway for 5 km, then turns back and flies downwind for 6 km, then turns back again and flies another 6 km. During this flight it is constantly gaining altitude. Then, after having flown the entire given route, it lands at the airport from which it took off or when start in the bush turns in an unknown direction and flies at a constant altitude. If the aircraft lands at the airport, the scenario starts again, i.e. the aircraft respawn to take-off again.
 
 You can disconnect from the aircraft at any time, most often by pressing the `o` key (check help of your glider).
 
@@ -38,20 +38,20 @@ Default route
 1 - 1st waypoint
 2 - 2nd waypoint, etc.
 
-    2 . . 1   7
-    .     .   .
-    .     .   .
-    3     .   .
+    2 . . 1   5
     .     .   .
     .     .   .
     .     .   .
     .     .   .
     .     .   .
     .     .   .
-    .     ^   6
+    .     .   .
+    .     .   .
+    .     .   .
+    .     ^   .
     .         .
     .         .
-    4 . . . . 5
+    3 . . . . 4
 ```
 
 ## Menu of add-on
@@ -122,7 +122,7 @@ Many thanks to the FG forum user "wlbragg" for proposing and presenting a soluti
 
 ## Troubleshotting
 
-1. When I select `Aerotow Everywhere` -> `Call for Piper J3 Cub aircraft`, `Robin DR400` or `Cessana 182` from menu, I see "Let's fly!" message but nothing happened. The tow plane does not appear.
+1. When I select `Aerotow Everywhere` -> `Call for Piper J3 Cub aircraft`, `Robin DR400`, `Cessana 182` or `Douglas C-47` from menu, I see "Let's fly!" message but nothing happened. The tow plane does not appear.
 
 Probably you didn't include the `--data` command line option with the path where FlightGear should look for additional flight plan files for AI. Unfortunately, the simulator does not inform us that there was a problem with finding the flight plan file, so everything looks like it should work but does not.
 

addon-config.xml

@@ -58,10 +58,10 @@
                     </sound>
                     <help-text type="string">=== How to start? ===
 
-From the top menu, select "Aerotow Everywhere" -> "Call for Piper J3 Cub aircraft", "Robin DR400" or "Cessna 182" (yes, you can choose from many aircrafts).
-The tow aircraft will appear to your right and align to the centreline of the runway in front of you. At this time you should hook up to the aircraft, most often by `Ctrl-o` key (check help of your glider). The aircraft will begin to accelerate and take off.
+From the top menu, select "Aerotow Everywhere" -> "Call for Piper J3 Cub aircraft", "Robin DR400", "Cessna 182" or "Douglas C-47". (Yes, you can choose from many aircrafts.)
+The tow aircraft will appear to your right and align to the centreline of the runway in front of you. At this time you should hook up to the aircraft, most often by `Ctrl-o` key. Check help of your glider. The aircraft will begin to accelerate and take off.
 
-By default, the tow plane always takes off in front of your runway and flies along the runway for 5 km, then turns back and flies downwind for 6 km, then turns back again and flies another 6 km. During this flight it is constantly gaining altitude. Then when it has completed the entire set route it simply turns right 90 degrees and flies at a constant altitude.
+The tow plane always takes off in front of your runway and flies along the runway for 5 km, then turns back and flies downwind for 6 km, then turns back again and flies another 6 km. During this flight it is constantly gaining altitude. Then, after having flown the entire given route, it lands at the airport from which it took off or when start in the bush turns in an unknown direction and flies at a constant altitude. If the aircraft lands at the airport, the scenario starts again, i.e. the aircraft respawn to take-off again.
 
 You can disconnect from the aircraft at any time, most often by pressing the `o` key.
 

addon-main.nas

@@ -49,6 +49,7 @@ var loadExtraNasalFiles = func (addon) {
         "nasal/dialogs/thermal",
         "nasal/flight-plan",
         "nasal/scenario",
+        "nasal/io/waypoint",
         "nasal/io/flight-plan-writer",
         "nasal/aerotow",
         "aerotow",

addon-metadata.xml

@@ -21,7 +21,7 @@
     <addon>
         <identifier type="string">org.flightgear.addons.Aerotow</identifier>
         <name type="string">Aerotow Everywhere</name>
-        <version type="string">1.7.0</version>
+        <version type="string">1.8.1</version>
 
         <authors>
             <author>

gui/dialogs/about-aerotow.xml

@@ -45,7 +45,7 @@
     <hrule/>
 
     <text>
-        <label>Aerotow Everywhere version 1.7.0 - 26th August 2022</label>
+        <label>Aerotow Everywhere version 1.8.1 - 17th September 2022</label>
     </text>
 
     <text>

nasal/aerotow.nas

@@ -42,6 +42,7 @@ var Aerotow = {
     #
     del: func () {
         me.thermal.del();
+        me.scenario.del();
 
         foreach (var listener; me.listeners) {
             removelistener(listener);

nasal/aircraft.nas

@@ -26,21 +26,23 @@ var Aircraft = {
     # speedLimit - max speed
     # rolling - factor for rolling
     # minRwyLength - minimum runway length required, in meters
+    # minFinalLegDist - minimum distance for final leg in meters (for landing)
     # name - full name of aircraft used in route dialog
     # nameMenuCall - short name of aircraft for call a plane from menu
     # modelPath - Path to the aircraft model
     #
-    new: func (vs, speed, speedLimit, rolling, minRwyLength, name, nameMenuCall, modelPath) {
+    new: func (vs, speed, speedLimit, rolling, minRwyLength, minFinalLegDist, name, nameMenuCall, modelPath) {
         var obj = { parents: [Aircraft] };
 
-        obj.vs           = vs;
-        obj.speed        = speed;
-        obj.speedLimit   = speedLimit;
-        obj.rolling      = rolling;
-        obj.minRwyLength = minRwyLength;
-        obj.name         = name;
-        obj.nameMenuCall = nameMenuCall;
-        obj.modelPath    = modelPath;
+        obj.vs              = vs;
+        obj.speed           = speed;
+        obj.speedLimit      = speedLimit;
+        obj.rolling         = rolling;
+        obj.minRwyLength    = minRwyLength;
+        obj.minFinalLegDist = minFinalLegDist;
+        obj.name            = name;
+        obj.nameMenuCall    = nameMenuCall;
+        obj.modelPath       = modelPath;
 
         return obj;
     },
@@ -114,15 +116,16 @@ var AircraftCub = {
     #
     new: func () {
         return {
-            parents:      [Aircraft],
-            vs:           200,
-            speed:        55,
-            speedLimit:   60,
-            rolling:      1,
-            minRwyLength: 280,
-            name:         "Piper J3 Cub",
-            nameMenuCall: "Cub",
-            modelPath:    "Aircraft/Aerotow/Cub/Models/Cub-ai.xml",
+            parents:         [Aircraft],
+            vs:              200,
+            speed:           55,
+            speedLimit:      60,
+            rolling:         1,
+            minRwyLength:    280,
+            minFinalLegDist: 5000,
+            name:            "Piper J3 Cub",
+            nameMenuCall:    "Cub",
+            modelPath:       "Aircraft/Aerotow/Cub/Models/Cub-ai.xml",
         };
     },
 };
@@ -140,15 +143,16 @@ var AircraftRobin = {
     #
     new: func () {
         return {
-            parents:      [Aircraft],
-            vs:           285,
-            speed:        70,
-            speedLimit:   75,
-            rolling:      2,
-            minRwyLength: 470,
-            name:         "Robin DR400",
-            nameMenuCall: "DR400",
-            modelPath:    "Aircraft/Aerotow/DR400/Models/dr400-ai.xml",
+            parents:         [Aircraft],
+            vs:              285,
+            speed:           70,
+            speedLimit:      75,
+            rolling:         2,
+            minRwyLength:    470,
+            minFinalLegDist: 5400,
+            name:            "Robin DR400",
+            nameMenuCall:    "DR400",
+            modelPath:       "Aircraft/Aerotow/DR400/Models/dr400-ai.xml",
         };
     },
 };
@@ -163,15 +167,16 @@ var AircraftRobin = {
 var AircraftC182 = {
     new: func () {
         return {
-            parents:      [Aircraft],
-            vs:           295,
-            speed:        75,
-            speedLimit:   80,
-            rolling:      2.2,
-            minRwyLength: 508,
-            name:         "Cessna 182",
-            nameMenuCall: "c182",
-            modelPath:    "Aircraft/Aerotow/c182/Models/c182-ai.xml",
+            parents:         [Aircraft],
+            vs:              295,
+            speed:           75,
+            speedLimit:      80,
+            rolling:         2.2,
+            minRwyLength:    508,
+            minFinalLegDist: 5500,
+            name:            "Cessna 182",
+            nameMenuCall:    "c182",
+            modelPath:       "Aircraft/Aerotow/c182/Models/c182-ai.xml",
         };
     },
 };
@@ -186,15 +191,16 @@ var AircraftC182 = {
 var AircraftC47 = {
     new: func () {
         return {
-            parents:      [Aircraft],
-            vs:           310,
-            speed:        85,
-            speedLimit:   90,
-            rolling:      2.2,
-            minRwyLength: 508,
-            name:         "Douglas C-47",
-            nameMenuCall: "C47",
-            modelPath:    "Aircraft/Aerotow/C-47/Models/c-47-ai.xml",
+            parents:         [Aircraft],
+            vs:              310,
+            speed:           85,
+            speedLimit:      90,
+            rolling:         2.2,
+            minRwyLength:    508,
+            minFinalLegDist: 6000,
+            name:            "Douglas C-47",
+            nameMenuCall:    "C47",
+            modelPath:       "Aircraft/Aerotow/C-47/Models/c-47-ai.xml",
         };
     },
 };

nasal/dialogs/route.nas

@@ -17,11 +17,13 @@ var RouteDialog = {
     # Constants
     #
     ROUTE_SAVES_DIR: "route-saves",
+    MAX_ROUTE_WAYPOINTS: 10,
 
     #
     # Constructor
     #
     # addon - Addon object
+    # message - Message object
     #
     new: func (addon, message) {
         var obj = { parents: [RouteDialog] };
@@ -31,7 +33,6 @@ var RouteDialog = {
         obj.addonNodePath = addon.node.getPath();
 
         obj.savePath = addon.storagePath ~ "/" ~ RouteDialog.ROUTE_SAVES_DIR;
-        obj.maxRouteWaypoints = 10;
         obj.listeners = [];
 
         # Set listener for aerotow combo box value in route dialog for recalculate altitude change
@@ -45,7 +46,7 @@ var RouteDialog = {
         }));
 
         # Set listeners for distance fields for calculate altitude change
-        for (var i = 0; i < obj.maxRouteWaypoints; i += 1) {
+        for (var i = 0; i < RouteDialog.MAX_ROUTE_WAYPOINTS; i += 1) {
             append(obj.listeners, setlistener(obj.addonNodePath ~ "/addon-devel/route/wpts/wpt[" ~ i ~ "]/distance-m", func () {
                 obj.calculateAltChangeAndTotals();
             }));
@@ -78,7 +79,7 @@ var RouteDialog = {
         # 0 means without altitude limits
         var maxAltAgl = getprop(me.addonNodePath ~ "/addon-devel/route/wpts/max-alt-agl") or 0;
 
-        for (var i = 0; i < me.maxRouteWaypoints; i += 1) {
+        for (var i = 0; i < RouteDialog.MAX_ROUTE_WAYPOINTS; i += 1) {
             var distance = getprop(me.addonNodePath ~ "/addon-devel/route/wpts/wpt[" ~ i ~ "]/distance-m") or 0;
 
             # If we have reached the altitude limit, the altitude no longer changes (0)

nasal/flight-plan.nas

@@ -36,7 +36,6 @@ var FlightPlan = {
 
         obj.addonNodePath = addon.node.getPath();
 
-        obj.wptCount      = 0;
         obj.coord         = nil; # Coordinates for flight plan
         obj.heading       = nil; # AI plane heading
         obj.altitude      = nil; # AI plane altitude
@@ -44,6 +43,13 @@ var FlightPlan = {
         return obj;
     },
 
+    #
+    # Destructor
+    #
+    del: func () {
+        me.flightPlanWriter.del();
+    },
+
     #
     # Get inital location of glider.
     #
@@ -70,10 +76,11 @@ var FlightPlan = {
         if (rwyResult.distance > FlightPlan.MAX_RUNWAY_DISTANCE) {
             # The runway is too far away, we assume a bush start
             return {
-                "type"    : "bush",
-                "lat"     : gliderCoord.lat(),
-                "lon"     : gliderCoord.lon(),
-                "heading" : getprop("/orientation/heading-deg"),
+                "type"     : "bush",
+                "lat"      : gliderCoord.lat(),
+                "lon"      : gliderCoord.lon(),
+                "heading"  : getprop("/orientation/heading-deg"),
+                "elevation": me.getEleveationInFt(gliderCoord),
             };
         }
 
@@ -89,10 +96,14 @@ var FlightPlan = {
         }
 
         return {
-            "type"    : "runway",
-            "lat"     : rwyResult.runway.lat,
-            "lon"     : rwyResult.runway.lon,
-            "heading" : rwyResult.runway.heading,
+            "type"     : "runway",
+            "lat"      : rwyResult.runway.lat,
+            "lon"      : rwyResult.runway.lon,
+            "heading"  : rwyResult.runway.heading,
+            "elevation": me.getEleveationInFt(
+                geo.Coord.new().set_latlon(rwyResult.runway.lat, rwyResult.runway.lon)
+            ),
+            "length"   : rwyResult.runway.length,
         };
     },
 
@@ -149,11 +160,11 @@ var FlightPlan = {
         var wptData = [
             {"hdgChange": 0,   "dist": 5000, "altChange": aircraft.vs * 5},
             {"hdgChange": -90, "dist": 1000, "altChange": aircraft.vs},
-            {"hdgChange": -90, "dist": 1000, "altChange": aircraft.vs},
-            {"hdgChange": 0,   "dist": 5000, "altChange": aircraft.vs * 5},
+            {"hdgChange": -90, "dist": 6000, "altChange": aircraft.vs * 6},
             {"hdgChange": -90, "dist": 1500, "altChange": aircraft.vs * 1.5},
-            {"hdgChange": -90, "dist": 1000, "altChange": aircraft.vs},
-            {"hdgChange": 0,   "dist": 5000, "altChange": aircraft.vs * 5},
+            {"hdgChange": -90, "dist": 6000, "altChange": aircraft.vs * 6},
+            {"hdgChange": 0,   "dist": 0,    "altChange": 0},
+            {"hdgChange": 0,   "dist": 0,    "altChange": 0},
             {"hdgChange": 0,   "dist": 0,    "altChange": 0},
             {"hdgChange": 0,   "dist": 0,    "altChange": 0},
             {"hdgChange": 0,   "dist": 0,    "altChange": 0},
@@ -164,20 +175,20 @@ var FlightPlan = {
         # 1 - 1st waypoint
         # 2 - 2nd waypoint, etc.
         #
-        #     2 . . 1   7
-        #     .     .   .
-        #     .     .   .
-        #     3     .   .
+        #     2 . . 1   5
         #     .     .   .
         #     .     .   .
         #     .     .   .
         #     .     .   .
         #     .     .   .
         #     .     .   .
-        #     .     ^   6
+        #     .     .   .
+        #     .     .   .
+        #     .     .   .
+        #     .     ^   .
         #     .         .
         #     .         .
-        #     4 . . . . 5
+        #     3 . . . . 4
 
         var index = 0;
         foreach (var wpt; wptData) {
@@ -202,8 +213,6 @@ var FlightPlan = {
     # Return true on successful, otherwise false.
     #
     generateXml: func () {
-        me.wptCount = 0;
-
         var location = me.getLocation();
         if (location == nil) {
             return false;
@@ -218,7 +227,7 @@ var FlightPlan = {
 
         # Start at 2 o'clock from the glider...
         # Inital ktas must be >= 1.0
-        me.addWptGround({"hdgChange": 60, "dist": 25}, {"altChange": 0, "ktas": 5});
+        me.addWptGround({"shift": {"hdgChange": 60, "dist": 25, "altChange": 0}, "ktas": 5}); # 1
 
         # Reset coord and heading
         isGliderPos = false;
@@ -227,26 +236,26 @@ var FlightPlan = {
         var gliderOffsetM = me.getGliderOffsetFromRunwayThreshold(location);
 
         # ... and line up with the runway
-        me.addWptGround({"hdgChange": 0, "dist": me.getInitialDistance() + gliderOffsetM}, {"altChange": 0, "ktas": 2.5});
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": me.getInitialDistance() + gliderOffsetM, "altChange": 0}, "ktas": 2.5}); # 2
 
         # Rolling
-        me.addWptGround({"hdgChange": 0, "dist": 10}, {"altChange": 0, "ktas": 5});
-        me.addWptGround({"hdgChange": 0, "dist": 20}, {"altChange": 0, "ktas": 5});
-        me.addWptGround({"hdgChange": 0, "dist": 20}, {"altChange": 0, "ktas": aircraft.speed / 6});
-        me.addWptGround({"hdgChange": 0, "dist": 10}, {"altChange": 0, "ktas": aircraft.speed / 5});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 4});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 3.5});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 3});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 2.5});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 2});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 1.75});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 1.5});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed / 1.25});
-        me.addWptGround({"hdgChange": 0, "dist": 10 * aircraft.rolling}, {"altChange": 0, "ktas": aircraft.speed});
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10,                    "altChange": 0}, "ktas": 5}); # 3
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 20,                    "altChange": 0}, "ktas": 5}); # 4
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 20,                    "altChange": 0}, "ktas": aircraft.speed / 6}); # 5
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10,                    "altChange": 0}, "ktas": aircraft.speed / 5}); # 6
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 4}); # 7
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 3.5}); # 8
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 3}); # 9
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 2.5}); # 10
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 2}); # 11
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 1.75}); # 12
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 1.5}); # 13
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed / 1.25}); # 14
+        me.addWptGround({"shift": {"hdgChange": 0, "dist": 10 * aircraft.rolling, "altChange": 0}, "ktas": aircraft.speed}); # 15
 
         # Take-off
-        me.addWptAir({"hdgChange": 0,   "dist": 100 * aircraft.rolling}, {"elevationPlus": 3, "ktas": aircraft.speed * 1.05});
-        me.addWptAir({"hdgChange": 0,   "dist": 100}, {"altChange": aircraft.vs / 10, "ktas": aircraft.speed * 1.025});
+        me.addWptAir({   "shift": {"hdgChange": 0, "dist": 100 * aircraft.rolling, "elevation": 3}, "ktas": aircraft.speed * 1.05}); # 16
+        me.addWptAir({   "shift": {"hdgChange": 0, "dist": 100,     "altChange": aircraft.vs / 10}, "ktas": aircraft.speed * 1.025}); # 17
 
 
         # 0 means without altitude limits
@@ -281,10 +290,86 @@ var FlightPlan = {
 
             totalAlt += altChange;
 
-            me.addWptAir({"hdgChange": hdgChange, "dist": distance}, {"altChange": altChange, "ktas": ktas});
+            me.addWptAir({"shift": {"hdgChange": hdgChange, "dist": distance, "altChange": altChange}, "ktas": ktas});
         }
 
-        me.addWptEnd();
+        # Back to airport if possible
+        if (location.type == "runway") {
+            # Add extra near waypoint to keep plane in whole designed track
+            me.addWptAir({"shift": {"hdgChange": hdgChange, "dist": 100, "altChange": altChange}, "ktas": ktas});
+
+            var coordRwyThreshold = geo.Coord.new().set_latlon(location.lat, location.lon);;
+
+            # Check distance to runway threshold
+            var dostanceToThreshold = me.coord.distance_to(coordRwyThreshold);
+
+            # Reset variables
+            me.heading = location.heading; # runway heading
+            me.coord = coordRwyThreshold;
+
+            # Move o the left of the runway threshold
+            me.heading = me.correctHeading(me.heading - 90);
+            me.coord.apply_course_distance(me.heading, 1000);
+
+            # Add a waypoint to the left of the runway + 3000 m to the middle of length
+            # Descend as far as you can to max elevation + 3000 ft
+            var halfRwyLenght = location.length / 2;
+            var altAgl = me.altitude - location.elevation;
+            var elevation = altAgl - (aircraft.getAltChange(dostanceToThreshold) * 2);
+            if (elevation < 3000) {
+                elevation = 3000;
+            }
+            me.addWptAir({"shift": {"hdgChange": 90, "dist": halfRwyLenght, "elevation": elevation}, "ktas": aircraft.speed});
+
+            # Fly downwind away of threshold, how far depend of the altitude
+            var desiredElevation = 1400;
+            var distance = (((elevation - desiredElevation) / (aircraft.vs * 2)) * 1000);
+            if (distance < aircraft.minFinalLegDist) {
+                distance = aircraft.minFinalLegDist;
+            }
+            me.addWptAir({"shift": {"hdgChange": -180, "dist": halfRwyLenght + distance, "elevation": desiredElevation}, "ktas": aircraft.speed});
+
+            # Turn to base leg
+            me.addWptAir({"shift": {"hdgChange": -90, "dist": 1000, "elevation": 1000}, "ktas": aircraft.speed, "flapsDown": true});
+
+            # Reset variables
+            me.coord = geo.Coord.new().set_latlon(location.lat, location.lon); # runway threshold
+
+            # Turn on final
+            me.addWptAir({
+                "coord"    : me.coord,
+                "crossAt"  : location.elevation + 10,
+                "ktas"     : aircraft.speed * 0.75,
+                "flapsDown": true,
+                "gearDown" : true,
+            });
+
+            # Reset variables
+            me.heading = location.heading;
+
+            # Flare
+            me.addWptAir({
+                "shift"    : {"hdgChange": 0, "dist": 100, "elevation": 10},
+                "ktas"     : aircraft.speed * 0.7,
+                "flapsDown": true,
+                "gearDown" : true,
+            });
+
+            # Touchdown
+            me.addWptGround({"shift": {"hdgChange": 0, "dist": 200, "elevation": 0}, "ktas": aircraft.speed * 0.6});
+
+            # Break
+            me.addWptGround({"shift": {"hdgChange": 0, "dist": 200, "elevation": 0}, "ktas": aircraft.speed * 0.4});
+
+            # Slow down to 5 kt
+            me.addWptGround({"shift": {"hdgChange": 0, "dist": 50, "elevation": 0}, "ktas": 5});
+
+            # Turn right out of runway and full stop
+            me.addWptEnd({"shift": {"hdgChange": 90, "dist": 100, "elevation": 0}, "ktas": 0, "onGround": true});
+        }
+        else {
+            me.addWptEnd();
+        }
 
         me.flightPlanWriter.close();
 
@@ -345,26 +430,24 @@ var FlightPlan = {
     #
     # Add new waypoint on ground
     #
-    # coordOffset - Hash for calculate next coordinates (lat, lon), with following fields:
-    # {
-    #     hdgChange - How the aircraft's heading supposed to change? 0 - keep the same heading.
-    #     dis - Distance in meters to calculate next waypoint coordinates.
-    # }
-    # performance - Hash with following fields:
-    # {
-    #     altChange - How the aircraft's altitude is supposed to change? 0 - keep the same altitude.
-    #     ktas - True air speed of AI plane at the waypoint.
-    # }
+    # wptData - hash object with waypoint data
     #
-    addWptGround: func (coordOffset, performance) {
-        me.wrireWpt(nil, coordOffset, performance, "ground");
+    addWptGround: func (wptData) {
+        wptData.onGround = true;
+        me.addWpt(wptData);
     },
 
     #
     # Add new waypoint in air
     #
-    addWptAir: func (coordOffset, performance) {
-        me.wrireWpt(nil, coordOffset, performance, "air");
+    # wptData - hash object wtih waypoint data
+    #
+    addWptAir: func (wptData) {
+        if (contains(wptData, "onGround")) {
+            wptData.onGround = nil;
+        }
+
+        me.addWpt(wptData);
     },
 
     #
@@ -373,70 +456,115 @@ var FlightPlan = {
     # sec - Number of seconds for wait
     #
     addWptWait: func (sec) {
-        me.wrireWpt("WAIT", {}, {}, nil, sec);
+        me.addWpt({"waitSec": sec});
     },
 
     #
-    # Add "END" waypoint
+    # Add "END" waypoint with optional waypoint data
     #
-    addWptEnd: func () {
-        me.wrireWpt("END", {}, {});
+    addWptEnd: func (wptData = nil) {
+        if (wptData == nil) {
+            wptData = {};
+        }
+
+        wptData.name = "END";
+
+        me.addWpt(wptData);
     },
 
     #
-    # Write waypoint to flight plan file
+    # Add new waypoint with given waypoint data
     #
-    # name - The name of waypoint
-    # coordOffset.hdgChange - How the aircraft's heading supposed to change?
-    # coordOffset.dist - Distance in meters to calculate next waypoint coordinates
-    # performance.altChange - How the aircraft's altitude is supposed to change?
-    # performance.elevationPlus - Set aircraft altitude as current terrain elevation + given value in feets.
-    #                             It's best to use for the first point in the air to avoid the plane collapsing into
-    #                             the ground in a bumpy airport
-    # performance.ktas - True air speed of AI plane at the waypoint
-    # groundAir - Allowed value: "ground or "air". The "ground" means that AI plane is on the ground, "air" - in air
-    # sec - Number of seconds for "WAIT" waypoint
+    # wptData = {
+    #     shift: { - Optionally hash with data to calculate next coordinates (lat, lon) and altitude of waypoint
+    #         hdgChange - How the aircraft's heading supposed to change? 0 - keep the same heading.
+    #         dist      - Distance in meters to calculate next waypoint coordinates.
+    #         altChange - How the aircraft's altitude is supposed to change? 0 - keep the same altitude.
+    #         elevation - Set aircraft altitude as current terrain elevation + given value in feets.
+    #                     It's best to use for the first point in the air to avoid the plane collapsing into
+    #                     the ground in a bumpy airport.
+    #     },
+    #     coord     - The geo.Coord object, required if shift is not given
+    #     crossAt   - Altitude in feet, required if shift is not given
+    #     ktas      - True airspeed in knots, required
+    #     onGround  - If true then set on ground, otherwise set in air
+    #     flapsDown - If true then set flaps down, otherwise set flaps up
+    #     gearDown  - If true then set gear down, otherwise set gear up
+    #     waitSec   - Number of seconds for WIAT waypoint
+    # }
     #
-    wrireWpt: func (
-        name,
-        coordOffset,
-        performance,
-        groundAir = nil,
-        sec = nil
-    ) {
-        var coord = nil;
-        if (contains(coordOffset, "hdgChange") and contains(coordOffset, "dist")) {
-            me.heading += coordOffset.hdgChange;
-            if (me.heading < 0) {
-                me.heading += 360;
-            }
+    addWpt: func (wptData) {
+        if (contains(wptData, "shift")) {
+            me.shiftWpt(wptData.shift);
 
-            if (me.heading > 360) {
-                me.heading -= 360;
-            }
-
-            me.coord.apply_course_distance(me.heading, coordOffset.dist);
-            coord = me.coord;
+            # Set coord and crossAt updated by shiftWpt()
+            wptData.coord   = me.coord;
+            wptData.crossAt = me.altitude;
         }
 
-        var alt = nil;
-        if (coord != nil and contains(performance, "elevationPlus")) {
-            var elevation = geo.elevation(coord.lat(), coord.lon());
-            me.altitude = elevation == nil
-                ? me.altitude + performance.elevationPlus
-                : elevation * globals.M2FT + performance.elevationPlus;
-            alt = me.altitude;
-        }
-        else if (contains(performance, "altChange")) {
-            me.altitude += performance.altChange;
-            alt = me.altitude;
+        var wpt = Waypoint.new().setHashData(wptData);
+
+        me.flightPlanWriter.write(wpt);
+    },
+
+    #
+    # Calculate heading, coordinates and altitude from data in wptShift hash
+    #
+    # wptShift - hash object with data
+    #
+    shiftWpt: func (wptShift) {
+        if (!contains(wptShift, "hdgChange")) {
+            die("ERROR aerotow add-on: missing 'hdgChange' for computeWptShift");
         }
 
-        var ktas = contains(performance, "ktas") ? performance.ktas : nil;
+        if (!contains(wptShift, "dist")) {
+            die("ERROR aerotow add-on: missing 'dist' for computeWptShift");
+        }
 
-        name = name == nil ? me.wptCount : name;
-        me.flightPlanWriter.write(name, coord, alt, ktas, groundAir, sec);
+        # Shift heading and coordinates
+        me.heading = me.correctHeading(me.heading + wptShift.hdgChange);
+        me.coord.apply_course_distance(me.heading, wptShift.dist);
 
-        me.wptCount += 1;
+        if (contains(wptShift, "elevation")) {
+            # Set the altitude as the elevation for coordinates of the point plus the given elevation
+            me.altitude = me.getEleveationInFt(me.coord) + wptShift.elevation;
+            return;
+        }
+
+        if (contains(wptShift, "altChange")) {
+            # Change altitude by given altChange
+            me.altitude += wptShift.altChange;
+        }
+    },
+
+    #
+    # Correct the heading value that to be from 0 to 360
+    #
+    # heading - heading for correction
+    # Return heading in range from 0 to 360.
+    #
+    correctHeading: func (heading) {
+        if (heading < 0) {
+            heading += 360;
+        }
+
+        if (heading > 360) {
+            heading -= 360;
+        }
+
+        return heading;
+    },
+
+    #
+    # Get elevation of given coordinates in feet
+    #
+    # coord - geo.Coord object
+    #
+    getEleveationInFt: func (coord) {
+        if (coord == nil) {
+            return nil;
+        }
+
+        return geo.elevation(coord.lat(), coord.lon()) * globals.M2FT;
     },
 };

nasal/io/flight-plan-writer.nas

@@ -21,16 +21,30 @@ var FlightPlanWriter = {
     new: func (addon) {
         var obj = { parents: [FlightPlanWriter] };
 
-        obj.fpFileHandler = nil; # Handler for wrire flight plan to file
+        obj.fpFileHandler = nil; # Handler for wrire flight plan to the file
         obj.flightPlanPath = addon.storagePath ~ "/AI/FlightPlans/" ~ FlightPlan.FILENAME_FLIGHTPLAN;
+        obj.wptCount = 1;
 
         return obj;
     },
 
+    #
+    # Destructor
+    #
+    del: func () {
+        me.close();
+    },
+
     #
     # Open XML file to wrire flight plan
     #
     open: func () {
+        me.wptCount = 1;
+
+        if (me.fpFileHandler) {
+            io.close(me.fpFileHandler);
+        }
+
         me.fpFileHandler = io.open(me.flightPlanPath, "w");
 
         if (me.fpFileHandler) {
@@ -47,50 +61,61 @@ var FlightPlanWriter = {
     #
     # Write single waypoint to XML file with flight plan
     #
-    # name - Name of waypoint. Special names are: "WAIT", "END".
-    # coord - The Coord object
-    # alt - Altitude AMSL of AI plane
-    # ktas - True air speed of AI plane
-    # groundAir - Allowe value: "ground or "air". The "ground" means that AI plane is on the ground, "air" - in air
-    # sec - Number of seconds for "WAIT" waypoint
+    # wpt - Waypoint object
     #
-    write: func (name, coord = nil, alt = nil, ktas = nil, groundAir = nil, sec = nil) {
+    write: func (wpt) {
         if (!me.fpFileHandler) {
             return;
         }
 
-        var str = "        <wpt>\n"
-                ~ "            <name>" ~ name ~ "</name>\n";
+        if (wpt.name == nil) {
+            wpt.setName(me.wptCount);
+        }
 
-        if (coord != nil) {
-            str ~= "            <lat>" ~ coord.lat() ~ "</lat>\n";
-            str ~= "            <lon>" ~ coord.lon() ~ "</lon>\n";
+        var str = "        <wpt>\n"
+                ~ "            <name>" ~ wpt.name ~ "</name>\n";
+
+        if (wpt.coord != nil) {
+            str ~= "            <lat>" ~ wpt.coord.lat() ~ "</lat>\n";
+            str ~= "            <lon>" ~ wpt.coord.lon() ~ "</lon>\n";
             str ~= "            <!--\n"
-                 ~ "                 " ~ coord.lat() ~ "," ~ coord.lon() ~ "\n"
+                 ~ "                 " ~ wpt.coord.lat() ~ "," ~ wpt.coord.lon() ~ "\n"
                  ~ "            -->\n";
         }
 
-        if (alt != nil) {
-            # str ~= "            <alt>" ~ alt ~ "</alt>\n";
-            str ~= "            <crossat>" ~ alt ~ "</crossat>\n";
+        if (wpt.alt != nil) {
+            str ~= "            <alt>" ~ wpt.alt ~ "</alt>\n";
         }
 
-        if (ktas != nil) {
-            str ~= "            <ktas>" ~ ktas ~ "</ktas>\n";
+        if (wpt.crossAt != nil) {
+            str ~= "            <crossat>" ~ wpt.crossAt ~ "</crossat>\n";
         }
 
-        if (groundAir != nil) {
-            var onGround = groundAir == "ground" ? "true" : "false";
-            str ~= "            <on-ground>" ~ onGround ~ "</on-ground>\n";
+        if (wpt.ktas != nil) {
+            str ~= "            <ktas>" ~ wpt.ktas ~ "</ktas>\n";
         }
 
-        if (sec != nil) {
-            str ~= "            <time-sec>" ~ sec ~ "</time-sec>\n";
+        if (wpt.onGround != nil) {
+            str ~= "            <on-ground>" ~ (wpt.onGround ? "true" : "false") ~ "</on-ground>\n";
+        }
+
+        if (wpt.waitSec != nil) {
+            str ~= "            <time-sec>" ~ wpt.waitSec ~ "</time-sec>\n";
+        }
+
+        if (wpt.flapsDown != nil) {
+            str ~= "            <flaps-down>" ~ (wpt.flapsDown ? "true" : "false") ~ "</flaps-down>\n";
+        }
+
+        if (wpt.gearDown != nil) {
+            str ~= "            <gear-down>" ~ (wpt.gearDown ? "true" : "false") ~ "</gear-down>\n";
         }
 
         str ~= "        </wpt>\n";
 
         io.write(me.fpFileHandler, str);
+
+        me.wptCount += 1;
     },
 
     #

nasal/io/waypoint.nas

@@ -0,0 +1,175 @@
+#
+# Aerotow Everywhere - Add-on for FlightGear
+#
+# Written and developer by Roman Ludwicki (PlayeRom, SP-ROM)
+#
+# Copyright (C) 2022 Roman Ludwicki
+#
+# Aerotow Everywhere is an Open Source project and it is licensed
+# under the GNU Public License v3 (GPLv3)
+#
+
+#
+# Class Waypoint represent the data of waypoint in the flight plan.
+#
+var Waypoint = {
+    #
+    # Constructor
+    #
+    new: func () {
+        var obj = { parents: [Waypoint] };
+
+        obj.name      = nil; # Name of waypoint. Special names are: "WAIT", "END".
+        obj.coord     = nil; # geo.Coord object
+        obj.alt       = nil; # Altitude AMSL in feet
+        obj.crossAt   = nil; # Altitude AMSL in feet
+        obj.ktas      = nil; # True airspeed in knots
+        obj.onGround  = nil; # If true then on the ground, otherwise in air
+        obj.flapsDown = nil; # If true then flaps down, otherwise up
+        obj.gearDown  = nil; # If true then gear down, otherwise up
+        obj.waitSec   = nil; # Number of seconds for "WAIT" waypoint
+
+        return obj;
+    },
+
+    #
+    # Set name of waypoint
+    #
+    # name - Name of waypoint
+    #
+    setName: func (name) {
+        me.name = name;
+
+        return me;
+    },
+
+    #
+    # Set coordinates of waypoint
+    #
+    # coord - geo.Coord object
+    #
+    setCoord: func (coord) {
+        me.coord = coord;
+
+        return me;
+    },
+
+    #
+    # Set altitude in feet of waypoint
+    #
+    # alt - altitude in feet
+    #
+    setAlt: func (alt) {
+        me.alt = alt;
+
+        return me;
+    },
+
+    #
+    # Set altitude in feet of waypoint as cross at
+    #
+    # alt - altitude in feet
+    #
+    setCrossAt: func (crossAt) {
+        me.crossAt = crossAt;
+
+        return me;
+    },
+
+    #
+    # Set true airspeed in knots for waypoint
+    #
+    # ktas - true airspeed in knots
+    #
+    setKtas: func (ktas) {
+        me.ktas = ktas;
+
+        return me;
+    },
+
+    #
+    # Set waypoint on the ground
+    #
+    setOnGround: func () {
+        me.onGround = 1;
+
+        return me;
+    },
+
+    #
+    # Set flaps down
+    #
+    setFlapsDown: func () {
+        me.flapsDown = 1;
+
+        return me;
+    },
+
+    #
+    # Set gear down
+    #
+    setGearDown: func () {
+        me.gearDown = 1;
+
+        return me;
+    },
+
+    #
+    # Set number of seconds for WAIT waypoint. This force to use "WAIT" name.
+    #
+    # waitSec - Number of seconds
+    #
+    setWaitSec: func (waitSec) {
+        me.setName("WAIT"); # force WAIT name
+        me.waitSec = waitSec;
+
+        return me;
+    },
+
+    #
+    # Set all waypoint data from given hash object
+    #
+    setHashData: func (wptData) {
+        if (wptData == nil) {
+            return me;
+        }
+
+        if (contains(wptData, "name")) {
+            me.setName(wptData.name);
+        }
+
+        if (contains(wptData, "coord")) {
+            me.setCoord(wptData.coord);
+        }
+
+        if (contains(wptData, "crossAt")) {
+            me.setCrossAt(wptData.crossAt);
+        }
+
+        if (contains(wptData, "alt")) {
+            me.setAlt(wptData.alt);
+        }
+
+        if (contains(wptData, "ktas")) {
+            me.setKtas(wptData.ktas);
+        }
+
+        if (contains(wptData, "onGround") and wptData.onGround) {
+            me.setOnGround();
+        }
+
+        if (contains(wptData, "flapsDown") and wptData.flapsDown) {
+            me.setFlapsDown();
+        }
+
+        if (contains(wptData, "gearDown") and wptData.gearDown) {
+            me.setGearDown();
+        }
+
+        if (contains(wptData, "waitSec")) {
+            me.setWaitSec(wptData.waitSec);
+        }
+
+        return me;
+    }
+};

nasal/scenario.nas

@@ -56,6 +56,7 @@ var Scenario = {
     #
     del: func () {
         me.routeDialog.del();
+        me.flightPlan.del();
 
         foreach (var listener; me.listeners) {
             removelistener(listener);
@@ -84,7 +85,7 @@ var Scenario = {
                         "class":      "aerotow-dragger",
                         "model":      Aircraft.getSelected(me.addon).modelPath,
                         "flightplan": FlightPlan.FILENAME_FLIGHTPLAN,
-                        "repeat":     true, # start again indefinitely
+                        "repeat":     true, # start again indefinitely, it will work if the aircraft stops on the ground
                     }
                 }
             }