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A Nasal script for FlightGear landing drills in the 777, and some bug workarounds

New Versions

Below is what I call the "original series." They are still useful scripts, and they still serve certain conditions better than the new scripts. I have written a couple of new editions for different purposes, though. One is to simulate the crash of Asiana 214, the other gives you a landing score--maximum z-acceleration.

You'll want to read or skim my first page on this topic for background on what this is for and how to install and such.

v0.5.0

I changed landing parameters one more time, and for these parameters I had to make another change to FG itself: I changed the transition times of the landing gear(s -- 5 of them rather than 3) to, um, well less than 19 or 20 seconds, because I couldn't figure out any other way to make them come down in time.

"Distance" as in those coordinates equate to 0.7nm from the near end of KATL runway 9L. 0.7 is what you'd enter in "Position Aircraft in Air."

The CDATA is just for XHTML compliance, not part of the script <![CDATA[ # Nasal script for FlightGear # by Kwynn Buess # # This is to assist with landing drills--this automatically "presses" the many buttons you need before landing # # The script ******* ASSUMES CHANGES TO FG FILES ***** to fix what I think are either bugs or annoyances in my way. # I discuss this in detail on my web site at kwynn.com # specifically http://kwynn.com/t/3/04/FG/FlightGear_landing_drill_Nasal_script.html?fromScriptItself # # For changes up to v0.4.0, see my web site. Changes in 0.5.0: # # When reversers on, engines to idle # When reversers off, autobrake off # When speedbrake-lever off ("down," neither auto nor engaged), aileron, elevator, and elevator-trim to 0 var verbose = 1; # I recommend using true (1) once to make sure this is working, then set to 0 var glide_slope_tunnel_on = 0; var at_target_speed_kt = 130; # at = auto-throttle - what AT should be preset to var visibility = 300000; # meters var at_disarm_below = 400; # if below this level (in feet), disarm the L/R A/T ARM switches to prevent AT from "magically" turning back on var frameA = [1, 8, 18, 35, 50]; # frame numbers from start to re-force settings that are otherwise stubborn # frameA also affects AT if (verbose) print("Kwynn landing drill script v0.5.0 2013/05/02 8:04AM EDT"); # little or nothing changed since v0.4.5 2013/04/21 2:37AM EDT # listener variables var reinitL = nil; var atL = nil; var frameL = nil; var reverserL = nil; var speedbrakeLeverL = nil; var frameCount = 0; # read the logic bottom to top because functions must be defined before called var setOnceUponReInit = func { if (verbose) print( "init once" ); # you can see and change all these properties when running FG in Debug -> Browse Internal Properties # you can also search Program Files/FlighGear/data/*.nas and *.xml for these properties setprop("/controls/flight/flaps",1); # full flaps - 30 degrees setprop("/controls/flight/speedbrake-lever",1); # auto setprop("/instrumentation/afds/inputs/AP-disengage",1); setprop("/instrumentation/afds/inputs/FD",1); # flight director setprop("/autopilot/autobrake/step",1); setprop("/instrumentation/efis/mfd/display-mode","APP"); # APP / approach - yes you need both APP and 0 setprop("/instrumentation/efis/mfd/mode-num",0); # APP / approach - yes, both setprop("/instrumentation/afds/inputs/autothrottle-index",5); # SPD setprop("/environment/visibility-m", visibility); setprop("/environment/metar/max-visibility-m", visibility); setprop("/environment/metar/min-visibility-m", visibility - 1); setprop("/sim/sound/enabled",0); } var setPerFrame = func { setprop("/sim/rendering/glide-slope-tunnel", glide_slope_tunnel_on); setprop("/sim/fuel-fraction",0.065); # 19.7 X 1000 lbs - ready for landing setprop("/controls/gear/gear-down", 1); # setprop("/gear/gear[0]/position-norm", 1); # this would work, but transition time overrides. It could work to continuously override setprop("/autopilot/settings/target-speed-kt", at_target_speed_kt); setprop("/instrumentation/afds/inputs/lateral-index",4); # LOC (flight director indication only) setprop("/instrumentation/afds/inputs/vertical-index",6); # G/S (flight director ...) # setprop("/instrumentation/afds/inputs/autothrottle-index",0); # off # setprop("/instrumentation/afds/inputs/at-armed" ,0); # setprop("/instrumentation/afds/inputs/at-armed[1]",0); var thr = 0.287; setprop("/controls/engines/engine/throttle" , thr); setprop("/controls/engines/engine[1]/throttle", thr); } # some settings reset themselves several times over the first few frames. Counteract this var frame_listener_func = func { frameCount = frameCount + 1; var cont = 0; foreach(frame; frameA) if (frameCount == frame) cont = 1; if ((cont == 0) and (frameCount < frameA[-1])) return; var targetSpeed = getprop("/autopilot/settings/target-speed-kt"); if ((verbose) and (targetSpeed != nil)) print("framecount = " ~ frameCount ~ " target speed = " ~ targetSpeed); if ((targetSpeed == at_target_speed_kt) and (frameL != nil) and (frameCount >= frameA[-1])) { if (verbose) print("removing fc listener"); removelistener(frameL); # I have found that when target speed is ready, so is everything else, so no more need to listen frameL = nil; frameCount = frameCount + 1; # needed for logic below - 2013/04/16 00:48 - KMB setprop("/sim/sound/enabled",1); } setPerFrame(); } var at_listener_func = func { var ati = getprop("/instrumentation/afds/inputs/autothrottle-index"); var agl = getprop("/position/gear-agl-ft"); if (verbose) print("ati in at_l = " ~ ati); # if you turn auto-throttle off, turn off the A/T ARM switches so the AT does not "magically" reengage if ( (ati == 0) and (frameCount > frameA[-1]) and # without this condition, the first few frames will reset the ati (agl < at_disarm_below) # to be consistent with the intent of this before my change to the at files discussed on my site ) { if (verbose) print("disarming A/T L/R switches"); setprop("/instrumentation/afds/inputs/at-armed" ,0); setprop("/instrumentation/afds/inputs/at-armed[1]",0); removelistener(atL); atL = nil; } else if (ati == 2) # sometimes THR REF "magically" comes on. If so, set back to SPD setprop("/instrumentation/afds/inputs/autothrottle-index",5); } var post_landing_cleanup = func { setprop("/controls/flight/aileron" ,0); setprop("/controls/flight/elevator",0); setprop("/controls/flight/elevator-trim" ,0); setprop("/instrumentation/afds/inputs/FD",0); # flight director setprop("/instrumentation/efis/mfd/display-mode","MAP"); setprop("/instrumentation/efis/mfd/mode-num",2); setprop("/instrumentation/afds/inputs/AP-disengage",0); setprop("/instrumentation/afds/inputs/lateral-index",0); # LOC (flight director indication only) setprop("/instrumentation/afds/inputs/vertical-index",0); # G/S (flight director ...) } var reverser_listener_func = func { if (verbose) print("reverser listner func"); var rev = getprop("/controls/engines/engine/reverser"); var agl = getprop("/position/gear-agl-ft"); if ((rev == 1) and (agl < 25)) { setprop("/controls/engines/engine/throttle" ,0); setprop("/controls/engines/engine[1]/throttle",0); } if ((rev == 0) and (agl <= 0)) { setprop("/autopilot/autobrake/step", -1); # -1 = OFF; 0 == DISARM } } var speedbrakeLever_listener_func = func { if (verbose) print("speedbrakeLever listener func"); var sbl = getprop("/controls/flight/speedbrake-lever"); var agl = getprop("/position/gear-agl-ft"); if ((sbl == 0) and (agl <= 0)) post_landing_cleanup(); } var reinit_listener_func = func(from) { if (verbose) print("reinit_listener_func"); setOnceUponReInit(); frameCount = 0; if (atL == nil) atL = setlistener("/instrumentation/afds/inputs/autothrottle-index", at_listener_func , 1, 1); if (frameL == nil) frameL = setlistener("/sim/signals/frame" , frame_listener_func, 1, 1); if (reverserL == nil) reverserL = setlistener("/controls/engines/engine/reverser",reverser_listener_func, 1, 1); # NOTE - if you listen to speedbrake rather than speedbrake-lever, the listener fires several times a second, at least under some conditions # NOTE 2 - same problem with lever if (speedbrakeLeverL == nil) speedbrakeLeverL = setlistener("/controls/flight/speedbrake-lever",speedbrakeLever_listener_func, 1, 1); } if (reinitL == nil) reinitL = setlistener("/sim/signals/reinit", reinit_listener_func, 1,1); # END SCRIPT # # The mark below is the end of the CDATA, not part of the script ]]>

v0.4.0 (3rd released, general use)

The CDATA is just for XHTML compliance, not part of the script <![CDATA[ # Nasal script for FlightGear (FG v2.10.0.3, although it should work in 2.8.0.5 and maybe earlier) # by Kwynn Buess # # This is to assist with landing drills--this automatically "presses" the many buttons you need before landing # # The script ******* ASSUMES CHANGES TO FG FILES ***** to fix what I think are either bugs or annoyances in my way. # I discuss this in detail on my web site at kwynn.com # specifically http://kwynn.com/t/3/04/FG/FlightGear_landing_drill_Nasal_script.html?fromScriptItself # # See general Nasal language info at http://wiki.flightgear.org/Nasal # # CHANGED 2013/04/12 - 130 to 120 knots target AT speed - v0.3.1 - also fixed hard-coding of 130 # CHANGE 2 - glide slope tunnel off # CHANGE 3 - added visibility variable and setting # change 4 - sound off for first few frames # change 5 - >= to remove fc listener; allow if > fc, other changes to remove frame listener and still at work # change 6 - glide slope tunnel as variable var verbose = 1; # I recommend using true (1) once to make sure this is working, then set to 0 var glide_slope_tunnel_on = 1; var at_target_speed_kt = 130; # at = auto-throttle - what AT should be preset to var visibility = 19000; # meters var at_disarm_below = 400; # if below this level (in feet), disarm the L/R A/T ARM switches to prevent AT from "magically" turning back on var frameA = [1, 8, 18, 35, 50]; # frame numbers from start to re-force settings that are otherwise stubborn # frameA also affects AT if (verbose) print("Kwynn landing drill script v0.4.0 2013/04/18 2:49AM EDT"); # listener variables var reinitL = nil; var atL = nil; var frameL = nil; var frameCount = 0; # read the logic bottom to top because functions must be defined before called var setOnceUponReInit = func { if (verbose) print( "init once" ); # you can see and change all these properties when running FG in Debug -> Browse Internal Properties # you can also search Program Files/FlighGear/data/*.nas and *.xml for these properties setprop("/controls/flight/flaps",1); # full flaps - 30 degrees setprop("/controls/flight/speedbrake-lever",1); # auto setprop("/instrumentation/afds/inputs/AP-disengage",1); setprop("/instrumentation/afds/inputs/FD",1); # flight director setprop("/autopilot/autobrake/step",1); setprop("/instrumentation/efis/mfd/display-mode","APP"); # APP / approach - yes you need both APP and 0 setprop("/instrumentation/efis/mfd/mode-num",0); # APP / approach - yes, both setprop("/instrumentation/afds/inputs/autothrottle-index",5); # SPD setprop("/environment/visibility-m", visibility); setprop("/environment/metar/max-visibility-m", visibility); setprop("/environment/metar/min-visibility-m", visibility - 1); setprop("/sim/sound/enabled",0); } var setPerFrame = func { setprop("/sim/rendering/glide-slope-tunnel", glide_slope_tunnel_on); setprop("/sim/fuel-fraction",0.065); # 19.7 X 1000 lbs - ready for landing setprop("/controls/gear/gear-down", 1); setprop("/autopilot/settings/target-speed-kt", at_target_speed_kt); setprop("/instrumentation/afds/inputs/lateral-index",4); # LOC (flight director indication only) setprop("/instrumentation/afds/inputs/vertical-index",6); # G/S (flight director ...) } # some settings reset themselves several times over the first few frames. Counteract this var frame_listener_func = func { frameCount = frameCount + 1; var cont = 0; foreach(frame; frameA) if (frameCount == frame) cont = 1; if ((cont == 0) and (frameCount < frameA[-1])) return; var targetSpeed = getprop("/autopilot/settings/target-speed-kt"); if ((verbose) and (targetSpeed != nil)) print("framecount = " ~ frameCount ~ " target speed = " ~ targetSpeed); if ((targetSpeed == at_target_speed_kt) and (frameL != nil) and (frameCount >= frameA[-1])) { if (verbose) print("removing fc listener"); removelistener(frameL); # I have found that when target speed is ready, so is everything else, so no more need to listen frameL = nil; frameCount = frameCount + 1; # needed for logic below - 2013/04/16 00:48 - KMB setprop("/sim/sound/enabled",1); } setPerFrame(); } var at_listener_func = func { var ati = getprop("/instrumentation/afds/inputs/autothrottle-index"); var agl = getprop("/position/gear-agl-ft"); if (verbose) print("ati in at_l = " ~ ati); # if you turn auto-throttle off, turn off the A/T ARM switches so the AT does not "magically" reengage if ( (ati == 0) and (frameCount > frameA[-1]) and # without this condition, the first few frames will reset the ati (agl < at_disarm_below) # to be consistent with the intent of this before my change to the at files discussed on my site ) { if (verbose) print("disarming A/T L/R switches"); setprop("/instrumentation/afds/inputs/at-armed" ,0); setprop("/instrumentation/afds/inputs/at-armed[1]",0); removelistener(atL); atL = nil; } else if (ati == 2) # sometimes THR REF "magically" comes on. If so, set back to SPD setprop("/instrumentation/afds/inputs/autothrottle-index",5); } var reinit_listener_func = func(from) { if (verbose) print("reinit_listener_func"); setOnceUponReInit(); frameCount = 0; if (atL == nil) atL = setlistener("/instrumentation/afds/inputs/autothrottle-index", at_listener_func , 1, 1); if (frameL == nil) frameL = setlistener("/sim/signals/frame" , frame_listener_func, 1, 1); } if (reinitL == nil) reinitL = setlistener("/sim/signals/reinit", reinit_listener_func, 1,1); # note that I tried signals other than reinit, and I still had to use frames. There probably is a better way. # END SCRIPT # # The mark below is the end of the CDATA, not part of the script ]]>

Nasal

General info on Nasal so I don't have to mention it in my script anymore, to save space.

Second Web-Released, general use version - 0.3.0

Below is the second released version, 0.3.0; for reference and background, see my first page on this topic. You'll probably at least want to read the bullet points / list of initial conditions this sets--the purpose of the script.

This version assumes two changes I made to FlighGear files (and you can make, too): 1. a fix for auto speedbrakes, and 2. the auto-throttle fix.

The Script Itself (v0.3.0 - 2013/04/07 3:25am EDT)

The CDATA is just for XHTML compliance, not part of the script <![CDATA[ # Nasal script for FlightGear (FG v2.10.0.3, although it should work in 2.8.0.5 and maybe earlier) # by Kwynn Buess # # This is to assist with landing drills--this automatically "presses" the many buttons you need before landing # # The script ******* ASSUMES CHANGES TO FG FILES ***** to fix what I think are either bugs or annoyances in my way. # I discuss this in detail on my web site at kwynn.com # specifically http://kwynn.com/t/3/04/FG/FlightGear_landing_drill_Nasal_script.html?fromScriptItself # # See general Nasal language info at http://wiki.flightgear.org/Nasal var verbose = 1; # I recommend using true (1) once to make sure this is working, then set to 0 if (verbose) print("Kwynn landing drill script v0.3.0 2013/04/07 3:25am EDT"); var at_target_speed_kt = 130; # at = auto-throttle - what AT should be preset to var at_disarm_below = 400; # if below this level (in feet), disarm the L/R A/T ARM switches to prevent AT from "magically" turning back on var frameA = [1, 8, 18, 35, 50]; # frame numbers from start to re-force settings that are otherwise stubborn # frameA also affects AT # listener variables var reinitL = nil; var atL = nil; var frameL = nil; var frameCount = 0; # read the logic bottom to top because functions must be defined before called var setOnceUponReInit = func { if (verbose) print( "init once" ); # you can see and change all these properties when running FG in Debug -> Browse Internal Properties # you can also search Program Files/FlighGear/data/*.nas and *.xml for these properties setprop("/controls/flight/flaps",1); # full flaps - 30 degrees setprop("/controls/flight/speedbrake-lever",1); # auto setprop("/instrumentation/afds/inputs/AP-disengage",1); setprop("/instrumentation/afds/inputs/FD",1); # flight director setprop("/autopilot/autobrake/step",1); setprop("/instrumentation/efis/mfd/display-mode","APP"); # APP / approach - yes you need both APP and 0 setprop("/instrumentation/efis/mfd/mode-num",0); # APP / approach - yes, both setprop("/instrumentation/afds/inputs/autothrottle-index",5); # SPD } var setPerFrame = func { setprop("/sim/rendering/glide-slope-tunnel",1); setprop("/sim/fuel-fraction",0.065); # 19.7 X 1000 lbs - ready for landing setprop("/controls/gear/gear-down", 1); setprop("/autopilot/settings/target-speed-kt", 130); setprop("/instrumentation/afds/inputs/lateral-index",4); # LOC (flight director indication only) setprop("/instrumentation/afds/inputs/vertical-index",6); # G/S (flight director ...) } # some settings reset themselves several times over the first few frames. Counteract this var frame_listener_func = func { frameCount = frameCount + 1; var cont = 0; foreach(frame; frameA) if (frameCount == frame) cont = 1; if (cont == 0) return; var targetSpeed = getprop("/autopilot/settings/target-speed-kt"); if ((verbose) and (targetSpeed != nil)) print("framecount = " ~ frameCount ~ " target speed = " ~ targetSpeed); if ((targetSpeed == at_target_speed_kt) and (frameL != nil) and (frameCount > frameA[-1])) { removelistener(frameL); # I have found that when target speed is ready, so is everything else, so no more need to listen frameL = nil; } setPerFrame(); } var at_listener_func = func { var ati = getprop("/instrumentation/afds/inputs/autothrottle-index"); var agl = getprop("/position/gear-agl-ft"); if (verbose) print("ati in at_l = " ~ ati); # if you turn auto-throttle off, turn off the A/T ARM switches so the AT does not "magically" reengage if ( (ati == 0) and (frameCount > frameA[-1]) and # without this condition, the first few frames will reset the ati (agl < at_disarm_below) # to be consistent with the intent of this before my change to the at files discussed on my site ) { if (verbose) print("disarming A/T L/R switches"); setprop("/instrumentation/afds/inputs/at-armed" ,0); setprop("/instrumentation/afds/inputs/at-armed[1]",0); removelistener(atL); atL = nil; } else if (ati == 2) # sometimes THR REF "magically" comes on. If so, set back to SPD setprop("/instrumentation/afds/inputs/autothrottle-index",5); } var reinit_listener_func = func(from) { if (verbose) print("reinit_listener_func"); setOnceUponReInit(); frameCount = 0; if (atL == nil) atL = setlistener("/instrumentation/afds/inputs/autothrottle-index", at_listener_func , 1, 1); if (frameL == nil) frameL = setlistener("/sim/signals/frame" , frame_listener_func, 1, 1); } if (reinitL == nil) reinitL = setlistener("/sim/signals/reinit", reinit_listener_func, 1,1); # note that I tried signals other than reinit, and I still had to use frames. There probably is a better way. # END SCRIPT # the following is the end of the CDATA, not part of script ]]>

New Landing Parameters

I pushed my landings much closer to the runway with v0.3 over v0.2. New settings are:

Note on 0.3.0

This version (v0.3.0) is much cleaner. I learned a few things about Nasal. I am not fighting the auto speedbrake bug because I fixed it. I think I got rid of all the unpleasant side effects so that this could be used to keep on flying instead of landing.

A Geekier Version

A version that wasn't well tested, but would be of interest to programmers or FG fans who are considering taking up Nasal.

Release History

These are the versions that have gone on the web, as opposed to my internal versions.

• Looks like I lost track. As a page history, rather than script history, the header said, "round 3 - script v0.4.0, April 18" until 2013/08/08. I'm now calling another page "part 2."
• v0.4.0 2013/04/18 2:49AM
• v0.3.0 - 2013/04/07 3:25am EDT
• v0.2.5 - NOT for general use, the "Geekier Version." See above
• v0.2.0, 2013/04/04 11:44pm EDT