Features
The Runway Advisory and Awareness System can give a number of advisories:
| Feature |
RAAS
|
| On runway and alignment < 20 degrees |
|
| On short runway, announcing remaining distance |
|
| On runway (reminder) |
 Not done
|
| Approaching runway (on ground) when groundspeed < 40 knots |
|
| Approaching runway (airborne) when distance < 3 nm, alignment < 20 degrees, AFE is 300 - 750 ft |
|
| Approaching runway (airborne), announcing available distance |
|
| Distance remaining (during landing) when AGL < 100 feet and groundspeed > 40 knots |
|
| Distance remaining after rejected takeoff, past 50 % of runway and 7 knots below maximum groundspeed |
|
| Runway end when distance remaininig < 100 feet or 30 meters and groundspeed < 40 knots |
|
| Taxiway takeoff when groundspeed > 40 knots while not on runway |
Not done
|
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 747-8i.
| Tip Ask the developer of your favorite aircraft if you want it to support RAAS.
|
TODO
| Use *.groundnet.xml to detect when the aircraft is near a holding point to more accurately emit "approaching-runway" signal |
Not done
|
| Allow remaining-distance to be emitted while aircraft is not on ground |
Not done
|
| Allow to choose between 450 - 550 ft or 350 - 450 ft suppression of approaching-runway (in air) |
Not done
|
| Require climb rate to be < 450 ft/min for remaining-distance |
Not done
|
| Require the presence of a mk-viii (GPWS) module |
Not done
|
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
| Mode |
Emitted signals
|
| taxi-and-takeoff |
approaching-runway, on-runway, on-short-runway
|
| takeoff |
on-runway, on-short-runway
|
| approach |
approaching-runway, approaching-short-runway
|
Landing announcer
| 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:
<logger>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/logger.nas</file>
</logger>
<runway>
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway_announcer.nas</file>
</runway>
Add the following to the <nasal> element below the previous two:
<file>Aircraft/$YOUR_AIRCRAFT_FOLDER/Nasal/runway.nas</file>
Add the file runway.nas to your aircraft's Nasal folder. This file is aircraft specific and needs to be constructed using the steps below.
Nasal/runway.nas
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.
Step 1 of 3: Functions
First, create a number of functions to format and print messages:
# 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);
};
| Tip You might want to replace copilot_say().
|
Step 2 of 3: Announcers
Second, create configuration objects, override some of their parameters, create the announcers, and then connect the various signals to callbacks:
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 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";
# Create announcers
var takeoff_announcer = runway.TakeoffRunwayAnnounceClass.new(takeoff_config);
var landing_announcer = runway.LandingRunwayAnnounceClass.new(landing_config);
var stop_announcer = runway.make_stop_announcer_func(takeoff_announcer, landing_announcer);
var switch_to_takeoff = runway.make_switch_to_takeoff_func(takeoff_announcer, landing_announcer);
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));
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));Step 3 of 3: Listeners
Finally, set up a listener to detect when the aircraft is on the ground and when it is airborne:
# Depending on whether the aircraft is on the ground or not, it will start, stop, or change the modes of the announcers
var set_on_ground = runway.make_set_ground_func(takeoff_announcer, landing_announcer);
var init_announcers = func {
setlistener("/gear/on-ground", func (node) {
set_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();
});
| 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.
|
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:
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
# or approaching while airborne.
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
approach_afe_min_ft: 300,
approach_afe_max_ft: 750,
# Minimum and maximum altitude Above Field Elevation in feet. Used to
# decide whether to announce that the aircraft is approaching a runway.
approach_distance_max_nm: 3.0,
# Maximum distance in nautical miles of the aircraft to the
# approaching runway
The same applies to the configuration object landing_config:
distances_meter: [100, 300, 600, 900, 1200, 1500],
distances_feet: [500, 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: 20,
# 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