[[File:F-14 aerial refueling.jpg|thumb|An F-14 has connected its probe with the left drogue of a 707-TT tanker.]]
[[File:EC-137D aerial refueling.jpg|thumb|An EC-137D is flying behind a 707-TT tanker while the flying boom of the tanker is connected to the receptacle of the EC-137D.]]
[[File:EC-137D aerial refueling (seen from boomer).jpg|thumb|An EC-137D is flying behind a 707-TT tanker while the flying boom of the tanker is connected to the receptacle of the EC-137D. The aircraft is seen from the boomer's view.]]
[[File:F-15C aerial refueling.jpg|thumb|An F-15C is flying behind a 707-TT tanker while the flying boom of the tanker is connected to the receptacle of the F-15C.]]

User onox has created a modified 707-TT and EC-137D that allow air-to-air refueling with a moving boom and drogues.

In order to perform AAR with this modified 707-TT you need to download the modified [https://github.com/onox/707 707] and the [https://github.com/onox/ExpansionPack ExpansionPack]. The ExpansionPack allows the flying boom and drogues to move and follow aircraft. It is also needed to see the drogue and the hose. People wishing to perform refueling with the F-15 or F-14 should use the "ORF" branch from [https://github.com/NikolaiVChr/fg-aircraft.git NikolaiVChr/fg-aircraft]. The [https://github.com/onox/V-22 MV-22] provides the ability to install one drogue on its cargo door.

== Lag settings ==

It is very important to adjust the lag settings in Multiplayer > Lag Settings. Make sure you have FlightGear 2016.1 or higher. To determine the lag, you should ping one of the multiplayer server that both the tanker and the receiving aircraft are going to use. For example, to ping mpserver01, open a terminal and type "ping mpserver01.flightgear.org". Determine the average ping in milliseconds and convert it to seconds. For example, a ping of 123 milliseconds becomes 0.123. Open Multiplayer > Lag Settings, enable "Master switch" and "Apply to close mp". Then adjust the slider of "Lag adjustment". Most likely to be a positive number. Alternatively, you can open the "Internal properties" window (ignore this if you don't know what it is) and set /sim/multiplay/lag/offset directly.

Use an ethernet cable instead of wifi. Wifi may give you a very fluctuating ping time to the server.

== Using the drogues ==

Simply click on the Hose Drum Unit (HDU) to extend the hose and the drogue. The receiving aircraft needs to be within 10 meters of the drogue (this value might be lowered in the future) in order to connect with the drogue. The drogue will 'snap' to the probe and follow it, at least on the tanker's computer. On the receiving aircraft's computer it could be (visually) look to be not connected.

== Using the flying boom ==

Press the {{Key press|r}} key to move the flying boom to the ready position. Press {{Key press|d}} to disconnect. Press {{Key press|Shift}} + {{Key press|d}} to move to the off position or to perform an emergency disconnect. While the boom is ready and able to track a nearby aircraft, the "READY" light should be lit on the boomer's panel.

To move the boom manually, hold {{Key press|Ctrl}} and then move the mouse. To extend/retract the telescope of the boom, release {{Key press|Ctrl}} and use the mouse scroll wheel.

The receiving aircraft needs to be within 1 meter of the nozzle of the boom. Once connected, you have a few extra meters of margin. With correct lag settings several people have demonstrated to stay connected, even while in different continents.

== Modifying aircraft to be compatible with the flying boom or drogue ==

In order for the tanker to be able to detect compatible aircraft, the multiplayer model XML file of the aircraft that wants to have fuel needs to be modified. For example, the F-14B's Models/f-14b.xml file contains:

<syntaxhighlight lang="xml">
<multiplay>
<refuel>
<offset-x-m type="double">-7.1969</offset-x-m>
<offset-y-m type="double">1.0409</offset-y-m>
<offset-z-m type="double">0.0387</offset-z-m>
<type type="string">probe</type>
</refuel>
</multiplay>
</syntaxhighlight>

Aircraft that contain a receptacle, for connecting with the flying boom, should use the value "boom" instead of "probe". For example, the F-15C's Models/f15c.xml file contains:

<syntaxhighlight lang="xml">
<multiplay>
<refuel>
<offset-x-m type="double">-0.3457</offset-x-m>
<offset-y-m type="double">-1.6912</offset-y-m>
<offset-z-m type="double">0.7946</offset-z-m>
<type type="string">boom</type>
</refuel>
</multiplay>
</syntaxhighlight>

== Negotiating fuel flow ==

Once it has been implemented, this section will contain instructions how to make the receiving aircraft only add fuel when connected to the boom or a drogue.

== Missing features ==

Aircraft are not able to negotiate a fuel flow with the tanker yet. Currently many aircraft use the generic aar.nas code which just adds fuel if the aircraft is within range of any tanker, even when the aircraft is not connected to the tanker. The maximum fuel flow depends on the type (boom, drogue, or drogue connected to boom), the specific maximum that the receiving aircraft can handle, and the state of the tanks of the tanker and receiving aircraft. Both the tanker and the receiving aircraft should publish this number (which might change continuously) in a property. Both aircraft then need to take the minimum and consider this to be the fuel flow that they can add/subtract from their tanks.

There are no pilot director lights on the bottom of the tanker yet. The 707-TT uses ALS procedural lights for the navigation lights. These could be used as well for the PDL. See http://wiki.flightgear.org/Aerial_refueling_improvement_ideas_and_resources

The flying boom simply moves to a position indicated by the mouse. In reality (in the KC-135) the mouse should control the two flight control surfaces on the boom. It would be appreciated if someone creates a JSBSim system that lift/drag depending on state of the flight control surfaces and the current position.

{{air-to-air refueling}}

[[Category:Aircraft enhancement|Implement aerial refueling capability]]
[[Category:Howto|Implement aerial refueling capability]]
[[Category:Multiplayer]]

Multiplayer aerial refueling

2016-07-08T19:52:37Z

Onox:

Multiplayer aerial refueling

2016-07-08T19:43:37Z

Onox:

2014-09-28T09:30:04Z

Onox:

{{infobox subsystem

|name = Runway Awareness and Advisory System
|started = 08/2014
|description = System to give advisories about runways
|status = Under active development as of 08/2014
|developers = onox
|subforum = http://forum.flightgear.org/viewtopic.php?f=66&t=21266
}}

== Features ==

The Runway Advisory and Awareness System can give a number of advisories:

* Advisory when approaching a runway while taxiing if groundspeed is less than 40 knots

* Advisory when the aircraft is on the runway and aligned within 20 degrees with runway

* Advisory when the aircraft is on a short runway

* Advisory of remaining distance to the end of the runway during a landing while groundspeed is more than 40 knots and AGL less than 100 feet

* Advisory of remaining distance during RTO after passing 50 % of runway

https://www.youtube.com/watch?feature=player_detailpage&v=59ymnKUi49A#t=117

https://www.youtube.com/watch?feature=player_detailpage&v=0jkRhIMZAZo#t=171

== Aircraft ==

Currently RAAS is only used in the [https://github.com/dogsaysmoo/747-8i/ 747-8i].

{{tip|Complain to the developer of your favorite aircraft if you want it to support RAAS.}}

== TODO ==

{| class="wikitable"
|-
| Use *.groundnet.xml to detect when the aircraft is near a holding point to more accurately emit "approaching-runway" signal || {{Not done}}
|-
| Give an advisory of which runway the aircraft is lined up with when the aircraft is airborne and approaching a runway || {{Progressbar|100}}
|-
| Give "Approaching runway <runway>, <distance> available" advisory when the aircraft is airborne and approaching a short runway || {{Progressbar|100}}
|-
| Give "Long landing" caution when aircraft has less than a specified distance/percentage remaining || {{Not done}}
|-
| Give "On runway <runway>, <distance> remaining" advisory if remaining distance is less than required for a normal takeoff || {{Progressbar|100}}
|-
| Give remaining distance callouts after a rejected takeoff || {{Progressbar|100}}
|-
| Give "<distance> remaining" advisory if groundspeed is less than 40 knots and remaining distance is at most 30 meter or 100 feet || {{Not done}}
|-
| Allow aircraft developers to program whether between feet/meter should be used for distance remaining advisory || {{Progressbar|100}}
|-
| Allow distance from center to nose to be specified for a more accurate remaining distance || {{Progressbar|100}}
|-
| Allow distance_start_m to be nil so that on-runway signal will be emitted anywhere on the runway || {{Progressbar|100}}
|}

== Signals ==

In order to give these advisories, callbacks for a number of signals can be registered to two announcers. Depending on the current mode of each announcer they will emit certain signals:

=== Takeoff announcer ===

{| class="wikitable"
|-
! Mode !! Emitted signals
|-
| taxi-and-takeoff || approaching-runway, on-runway, on-short-runway
|-
| taxi || approaching-runway
|-
| takeoff || on-runway, on-short-runway
|-
| approach || approaching-runway, approaching-short-runway
|}

=== Landing announcer ===

{| class="wikitable"
|-
! Mode !! Emitted signals
|-
| takeoff || remaining-distance, vacated-runway
|-
| landing || remaining-distance, landed-runway, vacated-runway, landed-outside-runway
|}

== Installation ==

In case logger.nas and runway_announcer.nas have not been added to FlightGear's fgdata project yet, add the following to the beginning of the <nasal> element in your aircraft's -set.xml file:

<syntaxhighlight lang="xml">
<logger>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/logger.nas</file>
</logger>
<runway>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway_announcer.nas</file>
</runway>
</syntaxhighlight>

Add the following to the <nasal> element below the previous two:

<syntaxhighlight lang="xml">
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway.nas</file>
</syntaxhighlight>

Add the file runway.nas to your aircraft's Nasal folder. The following example listens to /gear/on-ground and overrides a number of properties of the takeoff_config object so that it can be used for large airliners.

=== Functions ===

First, create a number of functions to format and print messages, and to execute certain actions when some signals are emitted:

<syntaxhighlight lang="nasal">
# Copyright (C) 2014 onox
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

var copilot_say = func (message) {
setprop("/sim/messages/copilot", message);
logger.info(sprintf("Announcing '%s'", message));
};

var on_short_runway_format = func {
var distance = getprop("/sim/runway-announcer/short-runway-distance");
return sprintf("On runway %%s, %d %s remaining", distance, takeoff_config.distances_unit);
};

var approaching_short_runway_format = func {
var distance = takeoff_announcer.get_short_runway_distance();
return sprintf("Approaching runway %%s, %d %s available", distance, takeoff_config.distances_unit);
};

var remaining_distance_format = func {
return sprintf("%%d %s remaining", landing_config.distances_unit);
};

var stop_announcer = func {
landing_announcer.stop();
logger.warn("Stopping landing announcer");

takeoff_announcer.set_mode("taxi-and-takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));
};

var switch_to_takeoff = func {
# Switch to takeoff mode so that the "approaching-runway" signal
# is not emitted for any runways that are crossed during takeoff
if (takeoff_announcer.mode == "taxi-and-takeoff") {
takeoff_announcer.set_mode("takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));

landing_announcer.set_mode("takeoff");
landing_announcer.start();
logger.warn(sprintf("Starting landing (%s) announcer", landing_announcer.mode));
}
};
</syntaxhighlight>

=== Connecting signals ===

Second, create configuration objects, override some of their parameters, and then connect the various functions to callbacks:

<syntaxhighlight lang="nasal">
var takeoff_config = { parents: [runway.TakeoffRunwayAnnounceConfig] };

# You can modify this setting from a GUI during runtime
takeoff_config.distances_unit = "meter";

# Will cause the announcer to emit the "on-runway" signal if the
# aircraft is at most 15 meters from the center line of the runway
takeoff_config.distance_center_line_m = 15;

# Let the announcer emit the "approaching-runway" signal if the
# nose of the aircraft comes within 120 meters of the runway
takeoff_config.distance_edge_max_m = 150;

var takeoff_announcer = runway.TakeoffRunwayAnnounceClass.new(takeoff_config);
takeoff_announcer.connect("on-runway", runway.make_betty_cb(copilot_say, "On runway %s", switch_to_takeoff));
takeoff_announcer.connect("on-short-runway", runway.make_betty_cb(copilot_say, on_short_runway_format, switch_to_takeoff));
takeoff_announcer.connect("approaching-runway", runway.make_betty_cb(copilot_say, "Approaching runway %s"));
takeoff_announcer.connect("approaching-short-runway", runway.make_betty_cb(copilot_say, approaching_short_runway_format));

var landing_config = { parents: [runway.LandingRunwayAnnounceConfig] };
landing_config.distance_center_nose_m = 30;

# You can modify this setting from a GUI during runtime
landing_config.distances_unit = "meter";

var landing_announcer = runway.LandingRunwayAnnounceClass.new(landing_config);
landing_announcer.connect("remaining-distance", runway.make_betty_cb(copilot_say, remaining_distance_format));
landing_announcer.connect("vacated-runway", runway.make_betty_cb(copilot_say, "Vacated runway %s", stop_announcer));
landing_announcer.connect("landed-runway", runway.make_betty_cb(copilot_say, "Touchdown on runway %s"));
landing_announcer.connect("landed-outside-runway", runway.make_betty_cb(nil, nil, stop_announcer));
</syntaxhighlight>

=== Listeners ===

Finally, set up a listener to detect when the aircraft is on the ground and when it is airborne. Depending on this conditions, you need to start, stop, or change the modes of the announcers:

<syntaxhighlight lang="nasal">
var have_been_in_air = 0;

var test_on_ground = func (on_ground) {
if (on_ground) {
takeoff_announcer.start();
logger.warn("Starting takeoff announce");

if (have_been_in_air == 1) {
have_been_in_air = 0;

takeoff_announcer.set_mode("");

landing_announcer.set_mode("landing");
landing_announcer.start();
logger.warn(sprintf("Starting landing (%s) announcer", landing_announcer.mode));
}
else {
takeoff_announcer.set_mode("taxi-and-takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));
}
takeoff_announcer.start();
logger.warn(sprintf("Starting takeoff (%s) announcer", takeoff_announcer.mode));
}
else {
takeoff_announcer.set_mode("approach");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));

landing_announcer.stop();
logger.warn("Stopping landing announcer");

if (have_been_in_air == 0) {
have_been_in_air = 1;
}
}
};

var init_announcers = func {
setlistener("/gear/on-ground", func (node) {
test_on_ground(node.getBoolValue());
}, startup=1, runtime=0);
};

setlistener("/sim/signals/fdm-initialized", func {
var timer = maketimer(5.0, func init_announcers());
timer.singleShot = 1;
timer.start();
});
</syntaxhighlight>

{{Note|In this example the /gear/on-ground property is used to detect whether the aircraft is on the ground or in the air. Make sure to use a <logic> element in a <autopilot> XML file to set this to true or false depending on your gears' wow values.}}

{{Note|It is your responsibility to start and stop the announcers and to set the correct modes. Therefore it is necessary to connect to signals like landed-outside-runway and vacated-runway, even if they appear to be useless for your specific aircraft. The example of runway.nas above already does this for you.}}

{{tip|You might want to replace copilot_say().}}

== Configuring the announcers ==

The configuration object takeoff_config has a number of properties with default values. These properties can be modified if you want to change when certain signals are emitted. For example, in the example of runway.nas above, distance_center_line_m and distance_edge_max_m where overridden for large airliners. The defaults are:

<syntaxhighlight lang="nasal">
distance_start_m: nil,
# The maximum distance in meters from the starting position
# on the runway. Large runways are usually 40 to 60 meters wide
# to give you an idea of the scale. If nil then the distance is
# not taken into account, which means the aircraft can be anywhere
# on the runway for the on-runway signal to be emitted.

diff_runway_heading_deg: 20,
# Difference in heading between runway and aircraft in order to
# get an announcement that the aircraft is on the runway for takeoff.

diff_approach_heading_deg: 40,
# Maximum angle at which the aircraft should approach the runway.
# Must be higher than 0 and lower than 90.

distance_center_line_m: 10,
# The distance in meters from the center line of the runway

distance_edge_min_m: 20,
distance_edge_max_m: 80,
# Minimum and maximum distance in meters from the edge of the runway
# for announcing approaches.

nominal_distance_takeoff_m: 3000,
# Minimum distance in meters required for a normal takeoff. If
# remaining distance when entering the runway is less than the distance
# required for a normal takeoff, then the on-short-runway instead of
# on-runway signal will be emitted.

nominal_distance_landing_m: 2000,
# Minimum distance in meters required for a normal landing. If
# runway length when approaching the runway is less than the distance
# required for a normal landing, then the approaching-short-runway
# instead of approaching-runway signal will be emitted.

distances_unit: "meter",
# The unit to use for the remaining distance of short runways. Can
# be "meter" or "feet".

groundspeed_max_kt: 40,
# Maximum groundspeed in knots for approaching runway callouts
</syntaxhighlight>

The same applies to the configuration object landing_config:

<syntaxhighlight lang="nasal">
distances_meter: [ 30, 100, 300, 600, 900, 1200, 1500],

distances_feet: [100, 300, 1000, 2000, 3000, 4000, 5000],

distances_unit: "meter",
# The unit to use for the remaining distance. Can be "meter" or "feet"

distance_center_nose_m: 0,
# Distance from the center to the nose in meters

diff_runway_heading_deg: 15,
# Difference in heading between runway and aircraft in order to
# detect the correct runway on which the aircraft is landing.

groundspeed_min_kt: 40,
# Minimum groundspeed in knots for remaining distance callouts

agl_max_ft: 100,
# Maximum AGL in feet for remaining distance callouts
</syntaxhighlight>

Runway Awareness and Advisory System

2014-09-28T09:17:56Z

Onox:

{{infobox subsystem

|name = Runway Awareness and Advisory System
|started = 08/2014
|description = System to give advisories about runways
|status = Under active development as of 08/2014
|developers = onox
|subforum = http://forum.flightgear.org/viewtopic.php?f=66&t=21266
}}

== Features ==

The Runway Advisory and Awareness System can give a number of advisories:

* Advisory when approaching a runway while taxiing if groundspeed is less than 40 knots

* Advisory when the aircraft is on the runway and aligned within 20 degrees with runway

* Advisory when the aircraft is on a short runway

* Advisory of remaining distance to the end of the runway during a landing while groundspeed is more than 40 knots and AGL less than 100 feet

* Advisory of remaining distance during RTO after passing 50 % of runway

https://www.youtube.com/watch?feature=player_detailpage&v=59ymnKUi49A#t=117

https://www.youtube.com/watch?feature=player_detailpage&v=0jkRhIMZAZo#t=171

== TODO ==

{| class="wikitable"
|-
| Use *.groundnet.xml to detect when the aircraft is near a holding point to more accurately emit "approaching-runway" signal || {{Not done}}
|-
| Give an advisory of which runway the aircraft is lined up with when the aircraft is airborne and approaching a runway || {{Progressbar|100}}
|-
| Give "Approaching runway <runway>, <distance> available" advisory when the aircraft is airborne and approaching a short runway || {{Progressbar|100}}
|-
| Give "Long landing" caution when aircraft has less than a specified distance/percentage remaining || {{Not done}}
|-
| Give "On runway <runway>, <distance> remaining" advisory if remaining distance is less than required for a normal takeoff || {{Progressbar|100}}
|-
| Give remaining distance callouts after a rejected takeoff || {{Progressbar|100}}
|-
| Give "<distance> remaining" advisory if groundspeed is less than 40 knots and remaining distance is at most 30 meter or 100 feet || {{Not done}}
|-
| Allow aircraft developers to program whether between feet/meter should be used for distance remaining advisory || {{Progressbar|100}}
|-
| Allow distance from center to nose to be specified for a more accurate remaining distance || {{Progressbar|100}}
|-
| Allow distance_start_m to be nil so that on-runway signal will be emitted anywhere on the runway || {{Progressbar|100}}
|}

== Signals ==

In order to give these advisories, callbacks for a number of signals can be registered to two announcers. Depending on the current mode of each announcer they will emit certain signals:

=== Takeoff announcer ===

{| class="wikitable"
|-
! Mode !! Emitted signals
|-
| taxi-and-takeoff || approaching-runway, on-runway, on-short-runway
|-
| taxi || approaching-runway
|-
| takeoff || on-runway, on-short-runway
|-
| approach || approaching-runway, approaching-short-runway
|}

=== Landing announcer ===

{| class="wikitable"
|-
! Mode !! Emitted signals
|-
| takeoff || remaining-distance, vacated-runway
|-
| landing || remaining-distance, landed-runway, vacated-runway, landed-outside-runway
|}

== Installation ==

In case logger.nas and runway_announcer.nas have not been added to FlightGear's fgdata project yet, add the following to the beginning of the <nasal> element in your aircraft's -set.xml file:

<syntaxhighlight lang="xml">
<logger>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/logger.nas</file>
</logger>
<runway>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway_announcer.nas</file>
</runway>
</syntaxhighlight>

Add the following to the <nasal> element below the previous two:

<syntaxhighlight lang="xml">
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway.nas</file>
</syntaxhighlight>

Add the file runway.nas to your aircraft's Nasal folder. The following example listens for gear[1] and gear[2] and overrides a number of properties of the takeoff_config object so that it can be used for large airliners:

<syntaxhighlight lang="nasal">
# Copyright (C) 2014 onox
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

var copilot_say = func (message) {
setprop("/sim/messages/copilot", message);
logger.info(sprintf("Announcing '%s'", message));
};

var on_short_runway_format = func {
var distance = getprop("/sim/runway-announcer/short-runway-distance");
return sprintf("On runway %%s, %d %s remaining", distance, takeoff_config.distances_unit);
};

var approaching_short_runway_format = func {
var distance = takeoff_announcer.get_short_runway_distance();
return sprintf("Approaching runway %%s, %d %s available", distance, takeoff_config.distances_unit);
};

var remaining_distance_format = func {
return sprintf("%%d %s remaining", landing_config.distances_unit);
};

var stop_announcer = func {
landing_announcer.stop();
logger.warn("Stopping landing announcer");

takeoff_announcer.set_mode("taxi-and-takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));
};

var switch_to_takeoff = func {
# Switch to takeoff mode so that the "approaching-runway" signal
# is not emitted for any runways that are crossed during takeoff
if (takeoff_announcer.mode == "taxi-and-takeoff") {
takeoff_announcer.set_mode("takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));

landing_announcer.set_mode("takeoff");
landing_announcer.start();
logger.warn(sprintf("Starting landing (%s) announcer", landing_announcer.mode));
}
};
</syntaxhighlight>

<syntaxhighlight lang="nasal">
var takeoff_config = { parents: [runway.TakeoffRunwayAnnounceConfig] };

# You can modify this setting from a GUI during runtime
takeoff_config.distances_unit = "meter";

# Will cause the announcer to emit the "on-runway" signal if the
# aircraft is at most 15 meters from the center line of the runway
takeoff_config.distance_center_line_m = 15;

# Let the announcer emit the "approaching-runway" signal if the
# nose of the aircraft comes within 120 meters of the runway
takeoff_config.distance_edge_max_m = 150;

var takeoff_announcer = runway.TakeoffRunwayAnnounceClass.new(takeoff_config);
takeoff_announcer.connect("on-runway", runway.make_betty_cb(copilot_say, "On runway %s", switch_to_takeoff));
takeoff_announcer.connect("on-short-runway", runway.make_betty_cb(copilot_say, on_short_runway_format, switch_to_takeoff));
takeoff_announcer.connect("approaching-runway", runway.make_betty_cb(copilot_say, "Approaching runway %s"));
takeoff_announcer.connect("approaching-short-runway", runway.make_betty_cb(copilot_say, approaching_short_runway_format));

var landing_config = { parents: [runway.LandingRunwayAnnounceConfig] };
landing_config.distance_center_nose_m = 30;

# You can modify this setting from a GUI during runtime
landing_config.distances_unit = "meter";

var landing_announcer = runway.LandingRunwayAnnounceClass.new(landing_config);
landing_announcer.connect("remaining-distance", runway.make_betty_cb(copilot_say, remaining_distance_format));
landing_announcer.connect("vacated-runway", runway.make_betty_cb(copilot_say, "Vacated runway %s", stop_announcer));
landing_announcer.connect("landed-runway", runway.make_betty_cb(copilot_say, "Touchdown on runway %s"));
landing_announcer.connect("landed-outside-runway", runway.make_betty_cb(nil, nil, stop_announcer));
</syntaxhighlight>

<syntaxhighlight lang="nasal">
var have_been_in_air = 0;

var test_on_ground = func (on_ground) {
if (on_ground) {
takeoff_announcer.start();
logger.warn("Starting takeoff announce");

if (have_been_in_air == 1) {
have_been_in_air = 0;

takeoff_announcer.set_mode("");

landing_announcer.set_mode("landing");
landing_announcer.start();
logger.warn(sprintf("Starting landing (%s) announcer", landing_announcer.mode));
}
else {
takeoff_announcer.set_mode("taxi-and-takeoff");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));
}
takeoff_announcer.start();
logger.warn(sprintf("Starting takeoff (%s) announcer", takeoff_announcer.mode));
}
else {
takeoff_announcer.set_mode("approach");
logger.warn(sprintf("Takeoff mode: %s", takeoff_announcer.mode));

landing_announcer.stop();
logger.warn("Stopping landing announcer");

if (have_been_in_air == 0) {
have_been_in_air = 1;
}
}
};

var init_announcers = func {
setlistener("/gear/on-ground", func (node) {
test_on_ground(node.getBoolValue());
}, startup=1, runtime=0);
};

setlistener("/sim/signals/fdm-initialized", func {
var timer = maketimer(5.0, func init_announcers());
timer.singleShot = 1;
timer.start();
});
</syntaxhighlight>

{{Note|In this example the /gear/on-ground property is used to detect whether the aircraft is on the ground or in the air. Make sure to use a <logic> element in a <autopilot> XML file to set this to true or false depending on your gears' wow values.}}

{{Note|It is your responsibility to start and stop the announcers and to set the correct modes. Therefore it is necessary to connect to signals like landed-outside-runway and vacated-runway, even if they appear to be useless for your specific aircraft. The example of runway.nas above already does this for you.}}

{{tip|You might want to replace copilot_say().}}

The configuration object takeoff_config has a number of properties with default values. These properties can be modified if you want to change when certain signals are emitted. For example, in the example of runway.nas above, distance_center_line_m and distance_edge_max_m where overridden for large airliners. The defaults are:

<syntaxhighlight lang="nasal">
distance_start_m: nil,
# The maximum distance in meters from the starting position
# on the runway. Large runways are usually 40 to 60 meters wide
# to give you an idea of the scale. If nil then the distance is
# not taken into account, which means the aircraft can be anywhere
# on the runway for the on-runway signal to be emitted.

diff_runway_heading_deg: 20,
# Difference in heading between runway and aircraft in order to
# get an announcement that the aircraft is on the runway for takeoff.

diff_approach_heading_deg: 40,
# Maximum angle at which the aircraft should approach the runway.
# Must be higher than 0 and lower than 90.

distance_center_line_m: 10,
# The distance in meters from the center line of the runway

distance_edge_min_m: 20,
distance_edge_max_m: 80,
# Minimum and maximum distance in meters from the edge of the runway
# for announcing approaches.

nominal_distance_takeoff_m: 3000,
# Minimum distance in meters required for a normal takeoff. If
# remaining distance when entering the runway is less than the distance
# required for a normal takeoff, then the on-short-runway instead of
# on-runway signal will be emitted.

nominal_distance_landing_m: 2000,
# Minimum distance in meters required for a normal landing. If
# runway length when approaching the runway is less than the distance
# required for a normal landing, then the approaching-short-runway
# instead of approaching-runway signal will be emitted.

distances_unit: "meter",
# The unit to use for the remaining distance of short runways. Can
# be "meter" or "feet".

groundspeed_max_kt: 40,
# Maximum groundspeed in knots for approaching runway callouts
</syntaxhighlight>

The same applies to the configuration object landing_config:

<syntaxhighlight lang="nasal">
distances_meter: [ 30, 100, 300, 600, 900, 1200, 1500],

distances_feet: [100, 300, 1000, 2000, 3000, 4000, 5000],

distances_unit: "meter",
# The unit to use for the remaining distance. Can be "meter" or "feet"

distance_center_nose_m: 0,
# Distance from the center to the nose in meters

diff_runway_heading_deg: 15,
# Difference in heading between runway and aircraft in order to
# detect the correct runway on which the aircraft is landing.

groundspeed_min_kt: 40,
# Minimum groundspeed in knots for remaining distance callouts

agl_max_ft: 100,
# Maximum AGL in feet for remaining distance callouts
</syntaxhighlight>