From: curt <curt>
Date: Thu, 19 Sep 2002 01:11:07 +0000 (+0000)
Subject: Split Nav/Com units out into their own source code file to continue the
X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=3d2311d884e6917f657058da6ba642048b63a2a5;p=flightgear.git

Split Nav/Com units out into their own source code file to continue the
process of simplifying radiostack.[ch]xx
---

diff --git a/src/Cockpit/Makefile.am b/src/Cockpit/Makefile.am
index 5796d2b98..19db9a624 100644
--- a/src/Cockpit/Makefile.am
+++ b/src/Cockpit/Makefile.am
@@ -9,6 +9,7 @@ libCockpit_a_SOURCES = \
 	hud_scal.cxx hud_tbi.cxx \
 	kr_87.cxx kr_87.hxx \
 	kt_70.cxx kt_70.hxx \
+	navcom.cxx navcom.hxx \
 	panel.cxx panel.hxx \
         panel_io.cxx panel_io.hxx \
 	radiostack.cxx radiostack.hxx \
diff --git a/src/Cockpit/navcom.cxx b/src/Cockpit/navcom.cxx
new file mode 100644
index 000000000..aa989de2b
--- /dev/null
+++ b/src/Cockpit/navcom.cxx
@@ -0,0 +1,644 @@
+// navcom.cxx -- class to manage a navcom instance
+//
+// Written by Curtis Olson, started April 2000.
+//
+// Copyright (C) 2000 - 2002  Curtis L. Olson - curt@flightgear.org
+//
+// 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, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <stdio.h>	// snprintf
+
+#include <simgear/compiler.h>
+#include <simgear/math/sg_random.h>
+
+#include <Aircraft/aircraft.hxx>
+#include <Navaids/ilslist.hxx>
+#include <Navaids/mkrbeacons.hxx>
+#include <Navaids/navlist.hxx>
+#include <Time/FGEventMgr.hxx>
+
+#include "navcom.hxx"
+
+#include <string>
+SG_USING_STD(string);
+
+
+/**
+ * Boy, this is ugly!  Make the VOR range vary by altitude difference.
+ */
+static double kludgeRange ( double stationElev, double aircraftElev,
+			    double nominalRange)
+{
+    // Assume that the nominal range (usually 50nm) applies at a 5,000
+    // ft difference.  Just a wild guess!
+    double factor = ((aircraftElev*SG_METER_TO_FEET) - stationElev) / 5000.0;
+    double range = fabs(nominalRange * factor);
+
+    // Clamp the range to keep it sane; for now, never less than 25%
+    // or more than 500% of nominal range.
+    if (range < nominalRange/4.0) {
+        range = nominalRange/4.0;
+    } else if (range > nominalRange*5.0) {
+        range = nominalRange*5.0;
+    }
+
+    return range;
+}
+
+
+// Constructor
+FGNavCom::FGNavCom() :
+    lon_node(fgGetNode("/position/longitude-deg", true)),
+    lat_node(fgGetNode("/position/latitude-deg", true)),
+    alt_node(fgGetNode("/position/altitude-ft", true)),
+    last_nav_ident(""),
+    last_nav_vor(false),
+    nav_play_count(0),
+    nav_last_time(0),
+    need_update(true),
+    comm_freq(0.0),
+    comm_alt_freq(0.0),
+    comm_vol_btn(0.0),
+    nav_freq(0.0),
+    nav_alt_freq(0.0),
+    nav_radial(0.0),
+    nav_vol_btn(0.0)
+{
+    SGPath path( globals->get_fg_root() );
+    SGPath term = path;
+    term.append( "Navaids/range.term" );
+    SGPath low = path;
+    low.append( "Navaids/range.low" );
+    SGPath high = path;
+    high.append( "Navaids/range.high" );
+
+    term_tbl = new SGInterpTable( term.str() );
+    low_tbl = new SGInterpTable( low.str() );
+    high_tbl = new SGInterpTable( high.str() );
+
+}
+
+
+// Destructor
+FGNavCom::~FGNavCom() 
+{
+    unbind();		// FIXME: should be called externally
+
+    delete term_tbl;
+    delete low_tbl;
+    delete high_tbl;
+}
+
+
+void
+FGNavCom::init ()
+{
+    morse.init();
+    beacon.init();
+
+    search();
+
+    update(0);			// FIXME: use dt
+}
+
+void
+FGNavCom::bind ()
+{
+    char propname[256];
+
+				// User inputs
+    sprintf( propname, "/radios/comm[%d]/frequencies/selected-mhz", index );
+    fgTie( propname, this, &FGNavCom::get_comm_freq, &FGNavCom::set_comm_freq );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/comm[%d]/frequencies/standby-mhz", index );
+    fgTie( propname, this,
+           &FGNavCom::get_comm_alt_freq, &FGNavCom::set_comm_alt_freq );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/comm[%d]/volume", index );
+    fgTie( propname, this,
+           &FGNavCom::get_comm_vol_btn, &FGNavCom::set_comm_vol_btn );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/comm[%d]/ident", index );
+    fgTie( propname, this,
+	  &FGNavCom::get_comm_ident_btn, &FGNavCom::set_comm_ident_btn );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/nav[%d]/frequencies/selected-mhz", index );
+    fgTie( propname, this,
+	  &FGNavCom::get_nav_freq, &FGNavCom::set_nav_freq );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/nav[%d]/frequencies/standby-mhz", index );
+    fgTie( propname , this,
+           &FGNavCom::get_nav_alt_freq, &FGNavCom::set_nav_alt_freq);
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/nav[%d]/radials/selected-deg", index );
+    fgTie( propname, this,
+           &FGNavCom::get_nav_sel_radial, &FGNavCom::set_nav_sel_radial );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/nav[%d]/volume", index );
+    fgTie( propname, this,
+           &FGNavCom::get_nav_vol_btn, &FGNavCom::set_nav_vol_btn );
+    fgSetArchivable( propname );
+
+    sprintf( propname, "/radios/nav[%d]/ident", index );
+    fgTie( propname, this,
+           &FGNavCom::get_nav_ident_btn, &FGNavCom::set_nav_ident_btn );
+    fgSetArchivable( propname );
+
+				// Radio outputs
+    sprintf( propname, "/radios/nav[%d]/radials/actual-deg", index );
+    fgTie( propname,  this, &FGNavCom::get_nav_radial );
+
+    sprintf( propname, "/radios/nav[%d]/to-flag", index );
+    fgTie( propname, this, &FGNavCom::get_nav_to_flag );
+
+    sprintf( propname, "/radios/nav[%d]/from-flag", index );
+    fgTie( propname, this, &FGNavCom::get_nav_from_flag );
+
+    sprintf( propname, "/radios/nav[%d]/in-range", index );
+    fgTie( propname, this, &FGNavCom::get_nav_inrange );
+
+    sprintf( propname, "/radios/nav[%d]/heading-needle-deflection", index );
+    fgTie( propname, this, &FGNavCom::get_nav_heading_needle_deflection );
+
+    sprintf( propname, "/radios/nav[%d]/gs-needle-deflection", index );
+    fgTie( propname, this, &FGNavCom::get_nav_gs_needle_deflection );
+}
+
+
+void
+FGNavCom::unbind ()
+{
+    char propname[256];
+
+    sprintf( propname, "/radios/comm[%d]/frequencies/selected-mhz", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/comm[%d]/frequencies/standby-mhz", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/comm[%d]/on", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/comm[%d]/ident", index );
+    fgUntie( propname );
+
+    sprintf( propname, "/radios/nav[%d]/frequencies/selected-mhz", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/frequencies/standby-mhz", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/radials/actual-deg", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/radials/selected-deg", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/on", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/ident", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/to-flag", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/from-flag", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/in-range", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/heading-needle-deflection", index );
+    fgUntie( propname );
+    sprintf( propname, "/radios/nav[%d]/gs-needle-deflection", index );
+    fgUntie( propname );
+}
+
+
+// model standard VOR/DME/TACAN service volumes as per AIM 1-1-8
+double FGNavCom::adjustNavRange( double stationElev, double aircraftElev,
+			      double nominalRange )
+{
+    // extend out actual usable range to be 1.3x the published safe range
+    const double usability_factor = 1.3;
+
+    // assumptions we model the standard service volume, plus
+    // ... rather than specifying a cylinder, we model a cone that
+    // contains the cylinder.  Then we put an upside down cone on top
+    // to model diminishing returns at too-high altitudes.
+
+    // altitude difference
+    double alt = ( aircraftElev * SG_METER_TO_FEET - stationElev );
+    // cout << "aircraft elev = " << aircraftElev * SG_METER_TO_FEET
+    //      << " station elev = " << stationElev << endl;
+
+    if ( nominalRange < 25.0 + SG_EPSILON ) {
+	// Standard Terminal Service Volume
+	return term_tbl->interpolate( alt ) * usability_factor;
+    } else if ( nominalRange < 50.0 + SG_EPSILON ) {
+	// Standard Low Altitude Service Volume
+	// table is based on range of 40, scale to actual range
+	return low_tbl->interpolate( alt ) * nominalRange / 40.0
+	    * usability_factor;
+    } else {
+	// Standard High Altitude Service Volume
+	// table is based on range of 130, scale to actual range
+	return high_tbl->interpolate( alt ) * nominalRange / 130.0
+	    * usability_factor;
+    }
+}
+
+
+// model standard ILS service volumes as per AIM 1-1-9
+double FGNavCom::adjustILSRange( double stationElev, double aircraftElev,
+				     double offsetDegrees, double distance )
+{
+    // assumptions we model the standard service volume, plus
+
+    // altitude difference
+    // double alt = ( aircraftElev * SG_METER_TO_FEET - stationElev );
+    double offset = fabs( offsetDegrees );
+
+    if ( offset < 10 ) {
+	return FG_ILS_DEFAULT_RANGE;
+    } else if ( offset < 35 ) {
+	return 10 + (35 - offset) * (FG_ILS_DEFAULT_RANGE - 10) / 25;
+    } else if ( offset < 45 ) {
+	return (45 - offset);
+    } else if ( offset > 170 ) {
+        return FG_ILS_DEFAULT_RANGE;
+    } else if ( offset > 145 ) {
+	return 10 + (offset - 145) * (FG_ILS_DEFAULT_RANGE - 10) / 25;
+    } else if ( offset > 135 ) {
+        return (offset - 135);
+    } else {
+	return 0;
+    }
+}
+
+
+// Update the various nav values based on position and valid tuned in navs
+void 
+FGNavCom::update(double dt) 
+{
+    double lon = lon_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+    double lat = lat_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+    double elev = alt_node->getDoubleValue() * SG_FEET_TO_METER;
+
+    need_update = false;
+
+    Point3D aircraft = sgGeodToCart( Point3D( lon, lat, elev ) );
+    Point3D station;
+    double az1, az2, s;
+
+    ////////////////////////////////////////////////////////////////////////
+    // Nav.
+    ////////////////////////////////////////////////////////////////////////
+
+    if ( nav_valid ) {
+	station = Point3D( nav_x, nav_y, nav_z );
+	nav_loc_dist = aircraft.distance3D( station );
+
+	if ( nav_has_gs ) {
+	    station = Point3D( nav_gs_x, nav_gs_y, nav_gs_z );
+	    nav_gs_dist = aircraft.distance3D( station );
+	} else {
+	    nav_gs_dist = 0.0;
+	}
+	
+	// wgs84 heading
+	geo_inverse_wgs_84( elev, lat * SGD_RADIANS_TO_DEGREES, lon * SGD_RADIANS_TO_DEGREES, 
+			    nav_loclat, nav_loclon,
+			    &az1, &az2, &s );
+	// cout << "az1 = " << az1 << " magvar = " << nav_magvar << endl;
+	nav_heading = az1 - nav_magvar;
+	// cout << " heading = " << nav_heading
+	//      << " dist = " << nav_dist << endl;
+
+	if ( nav_loc ) {
+	    double offset = nav_heading - nav_radial;
+	    while ( offset < -180.0 ) { offset += 360.0; }
+	    while ( offset > 180.0 ) { offset -= 360.0; }
+	    // cout << "ils offset = " << offset << endl;
+	    nav_effective_range = adjustILSRange(nav_elev, elev, offset,
+						  nav_loc_dist * SG_METER_TO_NM );
+	} else {
+	    nav_effective_range = adjustNavRange(nav_elev, elev, nav_range);
+	}
+	// cout << "nav range = " << nav_effective_range
+	//      << " (" << nav_range << ")" << endl;
+
+	if ( nav_loc_dist < nav_effective_range * SG_NM_TO_METER ) {
+	    nav_inrange = true;
+	} else if ( nav_loc_dist < 2 * nav_effective_range * SG_NM_TO_METER ) {
+	    nav_inrange = sg_random() < 
+		( 2 * nav_effective_range * SG_NM_TO_METER - nav_loc_dist ) /
+		(nav_effective_range * SG_NM_TO_METER);
+	} else {
+	    nav_inrange = false;
+	}
+
+	if ( !nav_loc ) {
+	    nav_radial = nav_sel_radial;
+	}
+    } else {
+	nav_inrange = false;
+	// cout << "not picking up vor. :-(" << endl;
+    }
+
+#ifdef ENABLE_AUDIO_SUPPORT
+    if ( nav_valid && nav_inrange ) {
+	// play station ident via audio system if on + ident,
+	// otherwise turn it off
+	if ( nav_vol_btn > 0.1 && nav_ident_btn ) {
+	    FGSimpleSound *sound;
+	    sound = globals->get_soundmgr()->find( nav_fx_name );
+            if ( sound != NULL ) {
+                sound->set_volume( nav_vol_btn );
+            } else {
+                SG_LOG( SG_COCKPIT, SG_ALERT,
+                        "Can't find nav-vor-ident sound" );
+            }
+	    sound = globals->get_soundmgr()->find( dme_fx_name );
+            if ( sound != NULL ) {
+                sound->set_volume( nav_vol_btn );
+            } else {
+                SG_LOG( SG_COCKPIT, SG_ALERT,
+                        "Can't find nav-dme-ident sound" );
+            }
+            cout << "nav_last_time = " << nav_last_time << " ";
+            cout << "cur_time = " << globals->get_time_params()->get_cur_time();
+	    if ( nav_last_time <
+		 globals->get_time_params()->get_cur_time() - 30 ) {
+		nav_last_time = globals->get_time_params()->get_cur_time();
+		nav_play_count = 0;
+	    }
+            cout << " nav_play_count = " << nav_play_count << endl;
+            cout << "playing = "
+                 << globals->get_soundmgr()->is_playing(nav_fx_name)
+                 << endl;
+	    if ( nav_play_count < 4 ) {
+		// play VOR ident
+		if ( !globals->get_soundmgr()->is_playing(nav_fx_name) ) {
+		    globals->get_soundmgr()->play_once( nav_fx_name );
+		    ++nav_play_count;
+                }
+	    } else if ( nav_play_count < 5 && nav_has_dme ) {
+		// play DME ident
+		if ( !globals->get_soundmgr()->is_playing(nav_fx_name) &&
+		     !globals->get_soundmgr()->is_playing(dme_fx_name) ) {
+		    globals->get_soundmgr()->play_once( dme_fx_name );
+		    ++nav_play_count;
+		}
+	    }
+	} else {
+	    globals->get_soundmgr()->stop( nav_fx_name );
+	    globals->get_soundmgr()->stop( dme_fx_name );
+	}
+    }
+#endif
+
+}
+
+
+// Update current nav/adf radio stations based on current postition
+void FGNavCom::search() 
+{
+    double lon = lon_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+    double lat = lat_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
+    double elev = alt_node->getDoubleValue() * SG_FEET_TO_METER;
+
+    FGILS ils;
+    FGNav nav;
+
+    ////////////////////////////////////////////////////////////////////////
+    // Nav.
+    ////////////////////////////////////////////////////////////////////////
+
+    if ( current_ilslist->query( lon, lat, elev, nav_freq, &ils ) ) {
+	nav_ident = ils.get_locident();
+	nav_valid = true;
+	if ( last_nav_ident != nav_ident || last_nav_vor ) {
+	    nav_trans_ident = ils.get_trans_ident();
+	    last_nav_ident = nav_ident;
+	    last_nav_vor = false;
+	    nav_loc = true;
+	    nav_has_dme = ils.get_has_dme();
+	    nav_has_gs = ils.get_has_gs();
+
+	    nav_loclon = ils.get_loclon();
+	    nav_loclat = ils.get_loclat();
+	    nav_gslon = ils.get_gslon();
+	    nav_gslat = ils.get_gslat();
+	    nav_elev = ils.get_gselev();
+	    nav_magvar = 0;
+	    nav_range = FG_ILS_DEFAULT_RANGE;
+	    nav_effective_range = nav_range;
+	    nav_target_gs = ils.get_gsangle();
+	    nav_radial = ils.get_locheading();
+	    while ( nav_radial <   0.0 ) { nav_radial += 360.0; }
+	    while ( nav_radial > 360.0 ) { nav_radial -= 360.0; }
+	    nav_x = ils.get_x();
+	    nav_y = ils.get_y();
+	    nav_z = ils.get_z();
+	    nav_gs_x = ils.get_gs_x();
+	    nav_gs_y = ils.get_gs_y();
+	    nav_gs_z = ils.get_gs_z();
+
+#ifdef ENABLE_AUDIO_SUPPORT
+	    if ( globals->get_soundmgr()->exists( nav_fx_name ) ) {
+		globals->get_soundmgr()->remove( nav_fx_name );
+	    }
+	    FGSimpleSound *sound;
+	    sound = morse.make_ident( nav_trans_ident, LO_FREQUENCY );
+	    sound->set_volume( 0.3 );
+	    globals->get_soundmgr()->add( sound, nav_fx_name );
+
+	    if ( globals->get_soundmgr()->exists( dme_fx_name ) ) {
+		globals->get_soundmgr()->remove( dme_fx_name );
+	    }
+	    sound = morse.make_ident( nav_trans_ident, HI_FREQUENCY );
+	    sound->set_volume( 0.3 );
+	    globals->get_soundmgr()->add( sound, dme_fx_name );
+
+	    int offset = (int)(sg_random() * 30.0);
+	    nav_play_count = offset / 4;
+	    nav_last_time = globals->get_time_params()->get_cur_time() -
+		offset;
+	    cout << "offset = " << offset << " play_count = "
+	         << nav_play_count
+	         << " nav_last_time = " << nav_last_time
+	         << " current time = "
+	         << globals->get_time_params()->get_cur_time() << endl;
+#endif
+
+	    // cout << "Found an ils station in range" << endl;
+	    // cout << " id = " << ils.get_locident() << endl;
+	}
+    } else if ( current_navlist->query( lon, lat, elev, nav_freq, &nav ) ) {
+	nav_ident = nav.get_ident();
+	nav_valid = true;
+	if ( last_nav_ident != nav_ident || !last_nav_vor ) {
+	    last_nav_ident = nav_ident;
+	    last_nav_vor = true;
+	    nav_trans_ident = nav.get_trans_ident();
+	    nav_loc = false;
+	    nav_has_dme = nav.get_has_dme();
+	    nav_has_gs = false;
+	    nav_loclon = nav.get_lon();
+	    nav_loclat = nav.get_lat();
+	    nav_elev = nav.get_elev();
+	    nav_magvar = nav.get_magvar();
+	    nav_range = nav.get_range();
+	    nav_effective_range = adjustNavRange(nav_elev, elev, nav_range);
+	    nav_target_gs = 0.0;
+	    nav_radial = nav_sel_radial;
+	    nav_x = nav.get_x();
+	    nav_y = nav.get_y();
+	    nav_z = nav.get_z();
+
+#ifdef ENABLE_AUDIO_SUPPORT
+	    if ( globals->get_soundmgr()->exists( nav_fx_name ) ) {
+		globals->get_soundmgr()->remove( nav_fx_name );
+	    }
+	    FGSimpleSound *sound;
+	    sound = morse.make_ident( nav_trans_ident, LO_FREQUENCY );
+	    sound->set_volume( 0.3 );
+	    if ( globals->get_soundmgr()->add( sound, nav_fx_name ) ) {
+                cout << "Added nav-vor-ident sound" << endl;
+            } else {
+                cout << "Failed to add v1-vor-ident sound" << endl;
+            }
+
+	    if ( globals->get_soundmgr()->exists( dme_fx_name ) ) {
+		globals->get_soundmgr()->remove( dme_fx_name );
+	    }
+	    sound = morse.make_ident( nav_trans_ident, HI_FREQUENCY );
+	    sound->set_volume( 0.3 );
+	    globals->get_soundmgr()->add( sound, dme_fx_name );
+
+	    int offset = (int)(sg_random() * 30.0);
+	    nav_play_count = offset / 4;
+	    nav_last_time = globals->get_time_params()->get_cur_time() -
+		offset;
+	    cout << "offset = " << offset << " play_count = "
+	         << nav_play_count << " nav_last_time = "
+	         << nav_last_time << " current time = "
+	         << globals->get_time_params()->get_cur_time() << endl;
+#endif
+
+	    // cout << "Found a vor station in range" << endl;
+	    // cout << " id = " << nav.get_ident() << endl;
+	}
+    } else {
+	nav_valid = false;
+	nav_ident = "";
+	nav_radial = 0;
+	nav_trans_ident = "";
+	last_nav_ident = "";
+#ifdef ENABLE_AUDIO_SUPPORT
+	if ( ! globals->get_soundmgr()->remove( nav_fx_name ) ) {
+            cout << "Failed to remove nav-vor-ident sound" << endl;
+        }
+	globals->get_soundmgr()->remove( dme_fx_name );
+#endif
+	// cout << "not picking up vor1. :-(" << endl;
+    }
+}
+
+
+// return the amount of heading needle deflection, returns a value
+// clamped to the range of ( -10 , 10 )
+double FGNavCom::get_nav_heading_needle_deflection() const {
+    double r;
+
+    if ( nav_inrange ) {
+        r = nav_heading - nav_radial;
+	// cout << "Radial = " << nav_radial 
+	//      << "  Bearing = " << nav_heading << endl;
+    
+	while ( r >  180.0 ) { r -= 360.0;}
+	while ( r < -180.0 ) { r += 360.0;}
+	if ( fabs(r) > 90.0 ) {
+	    r = ( r<0.0 ? -r-180.0 : -r+180.0 );
+	    if ( nav_loc ) {
+		r = -r;
+	    }
+	}
+
+	// According to Robin Peel, the ILS is 4x more sensitive than a vor
+	if ( nav_loc ) { r *= 4.0; }
+	if ( r < -10.0 ) { r = -10.0; }
+	if ( r >  10.0 ) { r = 10.0; }
+    } else {
+	r = 0.0;
+    }
+
+    return r;
+}
+
+
+// return the amount of glide slope needle deflection (.i.e. the
+// number of degrees we are off the glide slope * 5.0
+double FGNavCom::get_nav_gs_needle_deflection() const {
+    if ( nav_inrange && nav_has_gs ) {
+	double x = nav_gs_dist;
+	double y = (fgGetDouble("/position/altitude-ft") - nav_elev)
+            * SG_FEET_TO_METER;
+	double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
+	return (nav_target_gs - angle) * 5.0;
+    } else {
+	return 0.0;
+    }
+}
+
+
+/**
+ * Return true if the NAV TO flag should be active.
+ */
+bool 
+FGNavCom::get_nav_to_flag () const
+{
+  if (nav_inrange) {
+    double offset = fabs(nav_heading - nav_radial);
+    if (nav_loc)
+      return true;
+    else
+      return (offset <= 90.0 || offset >= 270.0);
+  } else {
+    return false;
+  }
+}
+
+
+/**
+ * Return true if the NAV FROM flag should be active.
+ */
+bool
+FGNavCom::get_nav_from_flag () const
+{
+  if (nav_inrange) {
+    double offset = fabs(nav_heading - nav_radial);
+    if (nav_loc)
+      return false;
+    else
+      return (offset > 90.0 && offset < 270.0);
+  } else {
+    return false;
+  }
+}
diff --git a/src/Cockpit/navcom.hxx b/src/Cockpit/navcom.hxx
new file mode 100644
index 000000000..94698eb21
--- /dev/null
+++ b/src/Cockpit/navcom.hxx
@@ -0,0 +1,209 @@
+// navcom.hxx -- class to manage a navcom instance
+//
+// Written by Curtis Olson, started April 2000.
+//
+// Copyright (C) 2000 - 2002  Curtis L. Olson - curt@flightgear.org
+//
+// 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, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifndef _FG_NAVCOM_HXX
+#define _FG_NAVCOM_HXX
+
+
+#include <Main/fgfs.hxx>
+#include <Main/fg_props.hxx>
+
+#include <simgear/compiler.h>
+
+#include <simgear/math/interpolater.hxx>
+#include <simgear/timing/timestamp.hxx>
+
+#include <Navaids/ilslist.hxx>
+#include <Navaids/navlist.hxx>
+#include <Sound/beacon.hxx>
+#include <Sound/morse.hxx>
+
+class FGNavCom : public FGSubsystem
+{
+    FGBeacon beacon;
+    FGMorse morse;
+
+    SGInterpTable *term_tbl;
+    SGInterpTable *low_tbl;
+    SGInterpTable *high_tbl;
+
+    SGPropertyNode *lon_node;
+    SGPropertyNode *lat_node;
+    SGPropertyNode *alt_node;
+
+    string last_nav_ident;
+    bool last_nav_vor;
+    int nav_play_count;
+    time_t nav_last_time;
+
+    int index;                  // used for property binding
+    char nav_fx_name[256];
+    char dme_fx_name[256];
+
+    bool need_update;
+
+    string comm_ident;
+    bool comm_valid;
+    bool comm_inrange;
+    double comm_freq;
+    double comm_alt_freq;
+    double comm_vol_btn;
+    bool comm_ident_btn;
+    double comm_x;
+    double comm_y;
+    double comm_z;
+    double comm_dist;
+    double comm_elev;
+    double comm_range;
+    double comm_effective_range;
+
+    string nav_ident;
+    string nav_trans_ident;
+    bool nav_valid;
+    bool nav_inrange;
+    bool nav_has_dme;
+    bool nav_has_gs;
+    bool nav_loc;
+    double nav_freq;
+    double nav_alt_freq;
+    double nav_radial;
+    double nav_sel_radial;
+    double nav_loclon;
+    double nav_loclat;
+    double nav_x;
+    double nav_y;
+    double nav_z;
+    double nav_loc_dist;
+    double nav_gslon;
+    double nav_gslat;
+    double nav_gs_x;
+    double nav_gs_y;
+    double nav_gs_z;
+    double nav_gs_dist;
+    SGTimeStamp prev_time;
+    SGTimeStamp curr_time;
+    double nav_elev;
+    double nav_range;
+    double nav_effective_range;
+    double nav_heading;
+    double nav_target_gs;
+    double nav_magvar;
+    double nav_vol_btn;
+    bool nav_ident_btn;
+
+    // model standard VOR/DME/TACAN service volumes as per AIM 1-1-8
+    double adjustNavRange( double stationElev, double aircraftElev,
+			   double nominalRange );
+
+    // model standard ILS service volumes as per AIM 1-1-9
+    double adjustILSRange( double stationElev, double aircraftElev,
+			   double offsetDegrees, double distance );
+
+public:
+
+    FGNavCom();
+    ~FGNavCom();
+
+    void init ();
+    void bind ();
+    void unbind ();
+    void update (double dt);
+
+    // Update nav/adf radios based on current postition
+    void search ();
+
+    inline void set_bind_index( int i ) {
+        index = i;
+        sprintf( nav_fx_name, "nav%d-vor-ident", index );
+        sprintf( dme_fx_name, "dme%d-vor-ident", index );
+    }
+
+    // COMM Setters
+    inline void set_comm_freq( double freq ) {
+	comm_freq = freq; need_update = true;
+    }
+    inline void set_comm_alt_freq( double freq ) { comm_alt_freq = freq; }
+    inline void set_comm_vol_btn( double val ) {
+	if ( val < 0.0 ) val = 0.0;
+	if ( val > 1.0 ) val = 1.0;
+	comm_vol_btn = val;
+    }
+    inline void set_comm_ident_btn( bool val ) { comm_ident_btn = val; }
+
+    // NAV Setters
+    inline void set_nav_freq( double freq ) {
+	nav_freq = freq; need_update = true;
+    }
+    inline void set_nav_alt_freq( double freq ) { nav_alt_freq = freq; }
+    inline void set_nav_sel_radial( double radial ) {
+	nav_sel_radial = radial; need_update = true;
+    }
+    inline void set_nav_vol_btn( double val ) {
+	if ( val < 0.0 ) val = 0.0;
+	if ( val > 1.0 ) val = 1.0;
+	nav_vol_btn = val;
+    }
+    inline void set_nav_ident_btn( bool val ) { nav_ident_btn = val; }
+
+    // COMM Accessors
+    inline double get_comm_freq () const { return comm_freq; }
+    inline double get_comm_alt_freq () const { return comm_alt_freq; }
+
+    // NAV Accessors
+    inline double get_nav_freq () const { return nav_freq; }
+    inline double get_nav_alt_freq () const { return nav_alt_freq; }
+    inline double get_nav_sel_radial() const { return nav_sel_radial; }
+
+    // Calculated values.
+    inline bool get_comm_inrange() const { return comm_inrange; }
+    inline double get_comm_vol_btn() const { return comm_vol_btn; }
+    inline bool get_comm_ident_btn() const { return comm_ident_btn; }
+
+    inline bool get_nav_inrange() const { return nav_inrange; }
+    bool get_nav_to_flag () const;
+    bool get_nav_from_flag () const;
+    inline bool get_nav_has_dme() const { return nav_has_dme; }
+    inline bool get_nav_dme_inrange () const {
+	return nav_inrange && nav_has_dme;
+    }
+    inline bool get_nav_has_gs() const { return nav_has_gs; }
+    inline bool get_nav_loc() const { return nav_loc; }
+    inline double get_nav_loclon() const { return nav_loclon; }
+    inline double get_nav_loclat() const { return nav_loclat; }
+    inline double get_nav_loc_dist() const { return nav_loc_dist; }
+    inline double get_nav_gslon() const { return nav_gslon; }
+    inline double get_nav_gslat() const { return nav_gslat; }
+    inline double get_nav_gs_dist() const { return nav_gs_dist; }
+    inline double get_nav_elev() const { return nav_elev; }
+    inline double get_nav_heading() const { return nav_heading; }
+    inline double get_nav_radial() const { return nav_radial; }
+    inline double get_nav_target_gs() const { return nav_target_gs; }
+    inline double get_nav_magvar() const { return nav_magvar; }
+    double get_nav_heading_needle_deflection() const;
+    double get_nav_gs_needle_deflection() const;
+    inline double get_nav_vol_btn() const { return nav_vol_btn; }
+    inline bool get_nav_ident_btn() const { return nav_ident_btn; }
+};
+
+
+#endif // _FG_NAVCOM_HXX
diff --git a/src/Cockpit/radiostack.cxx b/src/Cockpit/radiostack.cxx
index 54f235b47..264c33b11 100644
--- a/src/Cockpit/radiostack.cxx
+++ b/src/Cockpit/radiostack.cxx
@@ -41,11 +41,6 @@
 #include <string>
 SG_USING_STD(string);
 
-static int nav1_play_count = 0;
-static int nav2_play_count = 0;
-static time_t nav1_last_time = 0;
-static time_t nav2_last_time = 0;
-
 
 FGRadioStack *current_radiostack;
 
@@ -81,20 +76,6 @@ FGRadioStack::FGRadioStack() :
     lat_node(fgGetNode("/position/latitude-deg", true)),
     alt_node(fgGetNode("/position/altitude-ft", true)),
     need_update(true),
-    comm1_freq(0.0),
-    comm1_alt_freq(0.0),
-    comm1_vol_btn(0.0),
-    comm2_freq(0.0),
-    comm2_alt_freq(0.0),
-    comm2_vol_btn(0.0),
-    nav1_freq(0.0),
-    nav1_alt_freq(0.0),
-    nav1_radial(0.0),
-    nav1_vol_btn(0.0),
-    nav2_freq(0.0),
-    nav2_alt_freq(0.0),
-    nav2_radial(0.0),
-    nav2_vol_btn(0.0),
     dme_freq(0.0),
     dme_dist(0.0),
     dme_prev_dist(0.0),
@@ -122,6 +103,8 @@ FGRadioStack::FGRadioStack() :
 // Destructor
 FGRadioStack::~FGRadioStack() 
 {
+    navcom1.unbind();
+    navcom2.unbind();
     adf.unbind();
     xponder.unbind();
     unbind();			// FIXME: should be called externally
@@ -135,6 +118,12 @@ FGRadioStack::~FGRadioStack()
 void
 FGRadioStack::init ()
 {
+    navcom1.set_bind_index( 0 );
+    navcom1.init();
+
+    navcom2.set_bind_index( 1 );
+    navcom2.init();
+
     adf.init();
     xponder.init();
 
@@ -143,10 +132,14 @@ FGRadioStack::init ()
     blink.stamp();
 
     search();
+    navcom1.search();
+    navcom2.search();
     adf.search();
     xponder.search();
 
     update(0);			// FIXME: use dt
+    navcom1.update(0);
+    navcom2.update(0);
     adf.update(0);
     xponder.update(0);
 
@@ -159,97 +152,6 @@ FGRadioStack::init ()
 void
 FGRadioStack::bind ()
 {
-				// User inputs
-    fgTie("/radios/comm[0]/frequencies/selected-mhz", this,
-	  &FGRadioStack::get_comm1_freq, &FGRadioStack::set_comm1_freq);
-    fgSetArchivable("/radios/comm[0]/frequencies/selected-mhz");
-    fgTie("/radios/comm[0]/frequencies/standby-mhz", this,
-	  &FGRadioStack::get_comm1_alt_freq, &FGRadioStack::set_comm1_alt_freq);
-    fgSetArchivable("/radios/comm[0]/frequencies/standby-mhz");
-     fgTie("/radios/comm[0]/volume", this,
-	  &FGRadioStack::get_comm1_vol_btn,
-	  &FGRadioStack::set_comm1_vol_btn);
-    fgSetArchivable("/radios/comm[0]/volume");
-    fgTie("/radios/comm[0]/ident", this,
-	  &FGRadioStack::get_comm1_ident_btn,
-	  &FGRadioStack::set_comm1_ident_btn);
-    fgSetArchivable("/radios/comm[0]/ident");
-
-    fgTie("/radios/comm[1]/frequencies/selected-mhz", this,
-	  &FGRadioStack::get_comm2_freq, &FGRadioStack::set_comm2_freq);
-    fgSetArchivable("/radios/comm[0]/frequencies/selected-mhz");
-    fgTie("/radios/comm[1]/frequencies/standby-mhz", this,
-	  &FGRadioStack::get_comm2_alt_freq, &FGRadioStack::set_comm2_alt_freq);
-    fgSetArchivable("/radios/comm[0]/frequencies/standby-mhz");
-     fgTie("/radios/comm[1]/volume", this,
-	  &FGRadioStack::get_comm2_vol_btn,
-	  &FGRadioStack::set_comm2_vol_btn);
-    fgSetArchivable("/radios/comm[0]/volume");
-    fgTie("/radios/comm[1]/ident", this,
-	  &FGRadioStack::get_comm2_ident_btn,
-	  &FGRadioStack::set_comm2_ident_btn);
-    fgSetArchivable("/radios/comm[1]/ident");
-
-    fgTie("/radios/nav[0]/frequencies/selected-mhz", this,
-	  &FGRadioStack::get_nav1_freq, &FGRadioStack::set_nav1_freq);
-    fgSetArchivable("/radios/nav[0]/frequencies/selected-mhz");
-    fgTie("/radios/nav[0]/frequencies/standby-mhz", this,
-	  &FGRadioStack::get_nav1_alt_freq, &FGRadioStack::set_nav1_alt_freq);
-    fgSetArchivable("/radios/nav[0]/frequencies/standby-mhz");
-    fgTie("/radios/nav[0]/radials/selected-deg", this,
-	  &FGRadioStack::get_nav1_sel_radial,
-	  &FGRadioStack::set_nav1_sel_radial);
-    fgSetArchivable("/radios/nav[0]/radials/selected-deg");
-    fgTie("/radios/nav[0]/volume", this,
-	  &FGRadioStack::get_nav1_vol_btn,
-	  &FGRadioStack::set_nav1_vol_btn);
-    fgSetArchivable("/radios/nav[0]/volume");
-    fgTie("/radios/nav[0]/ident", this,
-	  &FGRadioStack::get_nav1_ident_btn,
-	  &FGRadioStack::set_nav1_ident_btn);
-    fgSetArchivable("/radios/nav[0]/ident");
-
-				// Radio outputs
-    fgTie("/radios/nav[0]/radials/actual-deg", this,
-	  &FGRadioStack::get_nav1_radial);
-    fgTie("/radios/nav[0]/to-flag", this, &FGRadioStack::get_nav1_to_flag);
-    fgTie("/radios/nav[0]/from-flag", this, &FGRadioStack::get_nav1_from_flag);
-    fgTie("/radios/nav[0]/in-range", this, &FGRadioStack::get_nav1_inrange);
-    fgTie("/radios/nav[0]/heading-needle-deflection", this,
-	  &FGRadioStack::get_nav1_heading_needle_deflection);
-    fgTie("/radios/nav[0]/gs-needle-deflection", this,
-	  &FGRadioStack::get_nav1_gs_needle_deflection);
-
-				// User inputs
-    fgTie("/radios/nav[1]/frequencies/selected-mhz", this,
-	  &FGRadioStack::get_nav2_freq, &FGRadioStack::set_nav2_freq);
-    fgSetArchivable("/radios/nav[1]/frequencies/selected-mhz");
-    fgTie("/radios/nav[1]/frequencies/standby-mhz", this,
-	  &FGRadioStack::get_nav2_alt_freq, &FGRadioStack::set_nav2_alt_freq);
-    fgSetArchivable("/radios/nav[1]/frequencies/standby-mhz");
-    fgTie("/radios/nav[1]/radials/selected-deg", this,
-	  &FGRadioStack::get_nav2_sel_radial,
-	  &FGRadioStack::set_nav2_sel_radial);
-    fgSetArchivable("/radios/nav[1]/radials/selected-deg");
-    fgTie("/radios/nav[1]/volume", this,
-	  &FGRadioStack::get_nav2_vol_btn,
-	  &FGRadioStack::set_nav2_vol_btn);
-    fgSetArchivable("/radios/nav[1]/volume");
-    fgTie("/radios/nav[1]/ident", this,
-	  &FGRadioStack::get_nav2_ident_btn,
-	  &FGRadioStack::set_nav2_ident_btn);
-    fgSetArchivable("/radios/nav[1]/ident");
-
-				// Radio outputs
-    fgTie("/radios/nav[1]/radials/actual-deg", this,
-	  &FGRadioStack::get_nav2_radial);
-    fgTie("/radios/nav[1]/to-flag", this, &FGRadioStack::get_nav2_to_flag);
-    fgTie("/radios/nav[1]/from-flag", this, &FGRadioStack::get_nav2_from_flag);
-    fgTie("/radios/nav[1]/in-range", this, &FGRadioStack::get_nav2_inrange);
-    fgTie("/radios/nav[1]/heading-needle-deflection", this,
-	  &FGRadioStack::get_nav2_heading_needle_deflection);
-    fgTie("/radios/nav[1]/gs-needle-deflection", this,
-	  &FGRadioStack::get_nav2_gs_needle_deflection);
 
 				// User inputs
     fgTie("/radios/dme/frequencies/selected-khz", this,
@@ -257,17 +159,26 @@ FGRadioStack::bind ()
 
 				// Radio outputs
     fgTie("/radios/dme/in-range", this, &FGRadioStack::get_dme_inrange);
+
     fgTie("/radios/dme/distance-nm", this, &FGRadioStack::get_dme_dist);
+
     fgTie("/radios/dme/speed-kt", this, &FGRadioStack::get_dme_spd);
+
     fgTie("/radios/dme/ete-min", this, &FGRadioStack::get_dme_ete);
 
     fgTie("/radios/marker-beacon/inner", this,
 	  &FGRadioStack::get_inner_blink);
+
     fgTie("/radios/marker-beacon/middle", this,
 	  &FGRadioStack::get_middle_blink);
+
     fgTie("/radios/marker-beacon/outer", this,
 	  &FGRadioStack::get_outer_blink);
 
+    navcom1.set_bind_index( 0 );
+    navcom1.bind();
+    navcom2.set_bind_index( 1 );
+    navcom2.bind();
     adf.bind();
     xponder.bind();
 }
@@ -275,40 +186,6 @@ FGRadioStack::bind ()
 void
 FGRadioStack::unbind ()
 {
-    fgUntie("/radios/comm[0]/frequencies/selected-mhz");
-    fgUntie("/radios/comm[0]/frequencies/standby-mhz");
-    fgUntie("/radios/comm[0]/on");
-    fgUntie("/radios/comm[0]/ident");
-
-    fgUntie("/radios/comm[1]/frequencies/selected-mhz");
-    fgUntie("/radios/comm[1]/frequencies/standby-mhz");
-    fgUntie("/radios/comm[1]/on");
-    fgUntie("/radios/comm[1]/ident");
-
-    fgUntie("/radios/nav[0]/frequencies/selected-mhz");
-    fgUntie("/radios/nav[0]/frequencies/standby-mhz");
-    fgUntie("/radios/nav[0]/radials/actual-deg");
-    fgUntie("/radios/nav[0]/radials/selected-deg");
-    fgUntie("/radios/nav[0]/on");
-    fgUntie("/radios/nav[0]/ident");
-    fgUntie("/radios/nav[0]/to-flag");
-    fgUntie("/radios/nav[0]/from-flag");
-    fgUntie("/radios/nav[0]/in-range");
-    fgUntie("/radios/nav[0]/heading-needle-deflection");
-    fgUntie("/radios/nav[0]/gs-needle-deflection");
-
-    fgUntie("/radios/nav[1]/frequencies/selected-mhz");
-    fgUntie("/radios/nav[1]/frequencies/standby-mhz");
-    fgUntie("/radios/nav[1]/radials/actual-deg");
-    fgUntie("/radios/nav[1]/radials/selected-deg");
-    fgUntie("/radios/nav[1]/on");
-    fgUntie("/radios/nav[1]/ident");
-    fgUntie("/radios/nav[1]/to-flag");
-    fgUntie("/radios/nav[1]/from-flag");
-    fgUntie("/radios/nav[1]/in-range");
-    fgUntie("/radios/nav[1]/heading-needle-deflection");
-    fgUntie("/radios/nav[1]/gs-needle-deflection");
-
     fgUntie("/radios/dme/frequencies/selected-khz");
 
 				// Radio outputs
@@ -321,6 +198,8 @@ FGRadioStack::unbind ()
     fgUntie("/radios/marker-beacon/middle");
     fgUntie("/radios/marker-beacon/outer");
 
+    navcom1.unbind();
+    navcom2.unbind();
     adf.unbind();
     xponder.unbind();
 }
@@ -400,216 +279,9 @@ FGRadioStack::update(double dt)
 
     Point3D aircraft = sgGeodToCart( Point3D( lon, lat, elev ) );
     Point3D station;
-    double az1, az2, s;
-
-    ////////////////////////////////////////////////////////////////////////
-    // Nav1.
-    ////////////////////////////////////////////////////////////////////////
-
-    if ( nav1_valid ) {
-	station = Point3D( nav1_x, nav1_y, nav1_z );
-	nav1_loc_dist = aircraft.distance3D( station );
-
-	if ( nav1_has_gs ) {
-	    station = Point3D( nav1_gs_x, nav1_gs_y, nav1_gs_z );
-	    nav1_gs_dist = aircraft.distance3D( station );
-	} else {
-	    nav1_gs_dist = 0.0;
-	}
-	
-	// wgs84 heading
-	geo_inverse_wgs_84( elev, lat * SGD_RADIANS_TO_DEGREES, lon * SGD_RADIANS_TO_DEGREES, 
-			    nav1_loclat, nav1_loclon,
-			    &az1, &az2, &s );
-	// cout << "az1 = " << az1 << " magvar = " << nav1_magvar << endl;
-	nav1_heading = az1 - nav1_magvar;
-	// cout << " heading = " << nav1_heading
-	//      << " dist = " << nav1_dist << endl;
-
-	if ( nav1_loc ) {
-	    double offset = nav1_heading - nav1_radial;
-	    while ( offset < -180.0 ) { offset += 360.0; }
-	    while ( offset > 180.0 ) { offset -= 360.0; }
-	    // cout << "ils offset = " << offset << endl;
-	    nav1_effective_range = adjustILSRange(nav1_elev, elev, offset,
-						  nav1_loc_dist * SG_METER_TO_NM );
-	} else {
-	    nav1_effective_range = adjustNavRange(nav1_elev, elev, nav1_range);
-	}
-	// cout << "nav1 range = " << nav1_effective_range
-	//      << " (" << nav1_range << ")" << endl;
-
-	if ( nav1_loc_dist < nav1_effective_range * SG_NM_TO_METER ) {
-	    nav1_inrange = true;
-	} else if ( nav1_loc_dist < 2 * nav1_effective_range * SG_NM_TO_METER ) {
-	    nav1_inrange = sg_random() < 
-		( 2 * nav1_effective_range * SG_NM_TO_METER - nav1_loc_dist ) /
-		(nav1_effective_range * SG_NM_TO_METER);
-	} else {
-	    nav1_inrange = false;
-	}
-
-	if ( !nav1_loc ) {
-	    nav1_radial = nav1_sel_radial;
-	}
-    } else {
-	nav1_inrange = false;
-	// cout << "not picking up vor. :-(" << endl;
-    }
-
-#ifdef ENABLE_AUDIO_SUPPORT
-    if ( nav1_valid && nav1_inrange ) {
-	// play station ident via audio system if on + ident,
-	// otherwise turn it off
-	if ( nav1_vol_btn > 0.1 && nav1_ident_btn ) {
-	    FGSimpleSound *sound;
-	    sound = globals->get_soundmgr()->find( "nav1-vor-ident" );
-            if ( sound != NULL ) {
-                sound->set_volume( nav1_vol_btn );
-            } else {
-                SG_LOG( SG_COCKPIT, SG_ALERT,
-                        "Can't find nav1-vor-ident sound" );
-            }
-	    sound = globals->get_soundmgr()->find( "nav1-dme-ident" );
-            if ( sound != NULL ) {
-                sound->set_volume( nav1_vol_btn );
-            } else {
-                SG_LOG( SG_COCKPIT, SG_ALERT,
-                        "Can't find nav1-dme-ident sound" );
-            }
-            // cout << "nav1_last_time = " << nav1_last_time << " ";
-            // cout << "cur_time = " << globals->get_time_params()->get_cur_time();
-	    if ( nav1_last_time <
-		 globals->get_time_params()->get_cur_time() - 30 ) {
-		nav1_last_time = globals->get_time_params()->get_cur_time();
-		nav1_play_count = 0;
-	    }
-            // cout << " nav1_play_count = " << nav1_play_count << endl;
-            // cout << "playing = "
-            //      << globals->get_soundmgr()->is_playing("nav1-vor-ident")
-            //      << endl;
-	    if ( nav1_play_count < 4 ) {
-		// play VOR ident
-		if ( !globals->get_soundmgr()->is_playing("nav1-vor-ident") ) {
-		    globals->get_soundmgr()->play_once( "nav1-vor-ident" );
-		    ++nav1_play_count;
-                }
-	    } else if ( nav1_play_count < 5 && nav1_has_dme ) {
-		// play DME ident
-		if ( !globals->get_soundmgr()->is_playing("nav1-vor-ident") &&
-		     !globals->get_soundmgr()->is_playing("nav1-dme-ident") ) {
-		    globals->get_soundmgr()->play_once( "nav1-dme-ident" );
-		    ++nav1_play_count;
-		}
-	    }
-	} else {
-	    globals->get_soundmgr()->stop( "nav1-vor-ident" );
-	    globals->get_soundmgr()->stop( "nav1-dme-ident" );
-	}
-    }
-#endif
-
-
-    ////////////////////////////////////////////////////////////////////////
-    // Nav2.
-    ////////////////////////////////////////////////////////////////////////
-
-    if ( nav2_valid ) {
-	station = Point3D( nav2_x, nav2_y, nav2_z );
-	nav2_loc_dist = aircraft.distance3D( station );
-
-	if ( nav2_has_gs ) {
-	    station = Point3D( nav2_gs_x, nav2_gs_y, nav2_gs_z );
-	    nav2_gs_dist = aircraft.distance3D( station );
-	} else {
-	    nav2_gs_dist = 0.0;
-	}
-
-	// wgs84 heading
-	geo_inverse_wgs_84( elev, lat * SGD_RADIANS_TO_DEGREES, lon * SGD_RADIANS_TO_DEGREES, 
-			    nav2_loclat, nav2_loclon,
-			    &az1, &az2, &s );
-	nav2_heading = az1 - nav2_magvar;
-	// cout << " heading = " << nav2_heading
-	//      << " dist = " << nav2_dist << endl;
-
-	if ( nav2_loc ) {
-	    double offset = nav2_heading - nav2_radial;
-	    while ( offset < -180.0 ) { offset += 360.0; }
-	    while ( offset > 180.0 ) { offset -= 360.0; }
-	    // cout << "ils offset = " << offset << endl;
-	    nav2_effective_range = adjustILSRange(nav2_elev, elev, offset,
-						  nav2_loc_dist * SG_METER_TO_NM );
-	} else {
-	    nav2_effective_range = adjustNavRange(nav2_elev, elev, nav2_range);
-	}
-	// cout << "nav2 range = " << nav2_effective_range
-	//      << " (" << nav2_range << ")" << endl;
-
-	if ( nav2_loc_dist < nav2_effective_range * SG_NM_TO_METER ) {
-	    nav2_inrange = true;
-	} else if ( nav2_loc_dist < 2 * nav2_effective_range * SG_NM_TO_METER ) {
-	    nav2_inrange = sg_random() < 
-		( 2 * nav2_effective_range * SG_NM_TO_METER - nav2_loc_dist ) /
-		(nav2_effective_range * SG_NM_TO_METER);
-	} else {
-	    nav2_inrange = false;
-	}
-
-	if ( !nav2_loc ) {
-	    nav2_radial = nav2_sel_radial;
-	}
-    } else {
-	nav2_inrange = false;
-	// cout << "not picking up vor. :-(" << endl;
-    }
-
-#ifdef ENABLE_AUDIO_SUPPORT
-    if ( nav2_valid && nav2_inrange ) {
-	// play station ident via audio system if on + ident,
-	// otherwise turn it off
-	if ( nav2_vol_btn > 0.1 && nav2_ident_btn ) {
-	    FGSimpleSound *sound;
-	    sound = globals->get_soundmgr()->find( "nav2-vor-ident" );
-            if ( sound != NULL ) {
-                sound->set_volume( nav2_vol_btn );
-            } else {
-                SG_LOG( SG_COCKPIT, SG_ALERT,
-                        "Can't find nav2-vor-ident sound" );
-            }
-	    sound = globals->get_soundmgr()->find( "nav2-dme-ident" );
-            if ( sound != NULL ) {
-                sound->set_volume( nav2_vol_btn );
-            } else {
-                SG_LOG( SG_COCKPIT, SG_ALERT,
-                        "Can't find nav2-dme-ident sound" );
-            }
-            if ( nav2_last_time <
-		 globals->get_time_params()->get_cur_time() - 30 ) {
-		nav2_last_time = globals->get_time_params()->get_cur_time();
-		nav2_play_count = 0;
-	    }
-	    if ( nav2_play_count < 4 ) {
-		// play VOR ident
-		if ( !globals->get_soundmgr()->is_playing("nav2-vor-ident") ) {
-		    globals->get_soundmgr()->play_once( "nav2-vor-ident" );
-		    ++nav2_play_count;
-		}
-	    } else if ( nav2_play_count < 5 && nav2_has_dme ) {
-		// play DME ident
-		if ( !globals->get_soundmgr()->is_playing("nav2-vor-ident") &&
-		     !globals->get_soundmgr()->is_playing("nav2-dme-ident") ) {
-		    globals->get_soundmgr()->play_once( "nav2-dme-ident" );
-		    ++nav2_play_count;
-		}
-	    }
-	} else {
-	    globals->get_soundmgr()->stop( "nav2-vor-ident" );
-	    globals->get_soundmgr()->stop( "nav2-dme-ident" );
-	}
-    }
-#endif
 
+    navcom1.update( dt );
+    navcom2.update( dt );
 
     ////////////////////////////////////////////////////////////////////////
     // DME.
@@ -712,13 +384,13 @@ void FGRadioStack::search()
       dme_freq = 0;
       dme_inrange = false;
     } else if (dme_switch_pos == 1) {
-      if (dme_freq != nav1_freq) {
-	dme_freq = nav1_freq;
+      if (dme_freq != navcom1.get_nav_freq()) {
+	dme_freq = navcom1.get_nav_freq();
 	need_update = true;
       }
     } else if (dme_switch_pos == 3) {
-      if (dme_freq != nav2_freq) {
-	dme_freq = nav2_freq;
+      if (dme_freq != navcom2.get_nav_freq()) {
+	dme_freq = navcom2.get_nav_freq();
 	need_update = true;
       }
     }
@@ -726,271 +398,8 @@ void FGRadioStack::search()
     FGILS ils;
     FGNav nav;
 
-    static string last_nav1_ident = "";
-    static string last_nav2_ident = "";
-    static bool last_nav1_vor = false;
-    static bool last_nav2_vor = false;
-
-    ////////////////////////////////////////////////////////////////////////
-    // Nav1.
-    ////////////////////////////////////////////////////////////////////////
-
-    if ( current_ilslist->query( lon, lat, elev, nav1_freq, &ils ) ) {
-	nav1_ident = ils.get_locident();
-	nav1_valid = true;
-	if ( last_nav1_ident != nav1_ident || last_nav1_vor ) {
-	    nav1_trans_ident = ils.get_trans_ident();
-	    last_nav1_ident = nav1_ident;
-	    last_nav1_vor = false;
-	    nav1_loc = true;
-	    nav1_has_dme = ils.get_has_dme();
-	    nav1_has_gs = ils.get_has_gs();
-
-	    nav1_loclon = ils.get_loclon();
-	    nav1_loclat = ils.get_loclat();
-	    nav1_gslon = ils.get_gslon();
-	    nav1_gslat = ils.get_gslat();
-	    nav1_elev = ils.get_gselev();
-	    nav1_magvar = 0;
-	    nav1_range = FG_ILS_DEFAULT_RANGE;
-	    nav1_effective_range = nav1_range;
-	    nav1_target_gs = ils.get_gsangle();
-	    nav1_radial = ils.get_locheading();
-	    while ( nav1_radial <   0.0 ) { nav1_radial += 360.0; }
-	    while ( nav1_radial > 360.0 ) { nav1_radial -= 360.0; }
-	    nav1_x = ils.get_x();
-	    nav1_y = ils.get_y();
-	    nav1_z = ils.get_z();
-	    nav1_gs_x = ils.get_gs_x();
-	    nav1_gs_y = ils.get_gs_y();
-	    nav1_gs_z = ils.get_gs_z();
-
-#ifdef ENABLE_AUDIO_SUPPORT
-	    if ( globals->get_soundmgr()->exists( "nav1-vor-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav1-vor-ident" );
-	    }
-	    FGSimpleSound *sound;
-	    sound = morse.make_ident( nav1_trans_ident, LO_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav1-vor-ident" );
-
-	    if ( globals->get_soundmgr()->exists( "nav1-dme-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav1-dme-ident" );
-	    }
-	    sound = morse.make_ident( nav1_trans_ident, HI_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav1-dme-ident" );
-
-	    int offset = (int)(sg_random() * 30.0);
-	    nav1_play_count = offset / 4;
-	    nav1_last_time = globals->get_time_params()->get_cur_time() -
-		offset;
-	    // cout << "offset = " << offset << " play_count = "
-	    //      << nav1_play_count
-	    //      << " nav1_last_time = " << nav1_last_time
-	    //      << " current time = "
-	    //      << globals->get_time_params()->get_cur_time() << endl;
-#endif
-
-	    // cout << "Found an ils station in range" << endl;
-	    // cout << " id = " << ils.get_locident() << endl;
-	}
-    } else if ( current_navlist->query( lon, lat, elev, nav1_freq, &nav ) ) {
-	nav1_ident = nav.get_ident();
-	nav1_valid = true;
-	if ( last_nav1_ident != nav1_ident || !last_nav1_vor ) {
-	    last_nav1_ident = nav1_ident;
-	    last_nav1_vor = true;
-	    nav1_trans_ident = nav.get_trans_ident();
-	    nav1_loc = false;
-	    nav1_has_dme = nav.get_has_dme();
-	    nav1_has_gs = false;
-	    nav1_loclon = nav.get_lon();
-	    nav1_loclat = nav.get_lat();
-	    nav1_elev = nav.get_elev();
-	    nav1_magvar = nav.get_magvar();
-	    nav1_range = nav.get_range();
-	    nav1_effective_range = adjustNavRange(nav1_elev, elev, nav1_range);
-	    nav1_target_gs = 0.0;
-	    nav1_radial = nav1_sel_radial;
-	    nav1_x = nav.get_x();
-	    nav1_y = nav.get_y();
-	    nav1_z = nav.get_z();
-
-#ifdef ENABLE_AUDIO_SUPPORT
-	    if ( globals->get_soundmgr()->exists( "nav1-vor-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav1-vor-ident" );
-	    }
-	    FGSimpleSound *sound;
-	    sound = morse.make_ident( nav1_trans_ident, LO_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    if ( globals->get_soundmgr()->add( sound, "nav1-vor-ident" ) ) {
-                // cout << "Added nav1-vor-ident sound" << endl;
-            } else {
-                // cout << "Failed to add v1-vor-ident sound" << endl;
-            }
-
-	    if ( globals->get_soundmgr()->exists( "nav1-dme-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav1-dme-ident" );
-	    }
-	    sound = morse.make_ident( nav1_trans_ident, HI_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav1-dme-ident" );
-
-	    int offset = (int)(sg_random() * 30.0);
-	    nav1_play_count = offset / 4;
-	    nav1_last_time = globals->get_time_params()->get_cur_time() -
-		offset;
-	    // cout << "offset = " << offset << " play_count = "
-	    //      << nav1_play_count << " nav1_last_time = "
-	    //      << nav1_last_time << " current time = "
-	    //      << globals->get_time_params()->get_cur_time() << endl;
-#endif
-
-	    // cout << "Found a vor station in range" << endl;
-	    // cout << " id = " << nav.get_ident() << endl;
-	}
-    } else {
-	nav1_valid = false;
-	nav1_ident = "";
-	nav1_radial = 0;
-	nav1_trans_ident = "";
-	last_nav1_ident = "";
-#ifdef ENABLE_AUDIO_SUPPORT
-	if ( ! globals->get_soundmgr()->remove( "nav1-vor-ident" ) ) {
-            // cout << "Failed to remove nav1-vor-ident sound" << endl;
-        }
-	globals->get_soundmgr()->remove( "nav1-dme-ident" );
-#endif
-	// cout << "not picking up vor1. :-(" << endl;
-    }
-
-
-    ////////////////////////////////////////////////////////////////////////
-    // Nav2.
-    ////////////////////////////////////////////////////////////////////////
-
-    if ( current_ilslist->query( lon, lat, elev, nav2_freq, &ils ) ) {
-	nav2_ident = ils.get_locident();
-	nav2_valid = true;
-	if ( last_nav2_ident != nav2_ident || last_nav2_vor ) {
-	    last_nav2_ident = nav2_ident;
-	    last_nav2_vor = false;
-	    nav2_trans_ident = ils.get_trans_ident();
-	    nav2_loc = true;
-	    nav2_has_dme = ils.get_has_dme();
-	    nav2_has_gs = ils.get_has_gs();
-
-	    nav2_loclon = ils.get_loclon();
-	    nav2_loclat = ils.get_loclat();
-	    nav2_elev = ils.get_gselev();
-	    nav2_magvar = 0;
-	    nav2_range = FG_ILS_DEFAULT_RANGE;
-	    nav2_effective_range = nav2_range;
-	    nav2_target_gs = ils.get_gsangle();
-	    nav2_radial = ils.get_locheading();
-	    while ( nav2_radial <   0.0 ) { nav2_radial += 360.0; }
-	    while ( nav2_radial > 360.0 ) { nav2_radial -= 360.0; }
-	    nav2_x = ils.get_x();
-	    nav2_y = ils.get_y();
-	    nav2_z = ils.get_z();
-	    nav2_gs_x = ils.get_gs_x();
-	    nav2_gs_y = ils.get_gs_y();
-	    nav2_gs_z = ils.get_gs_z();
-
-#ifdef ENABLE_AUDIO_SUPPORT
-	    if ( globals->get_soundmgr()->exists( "nav2-vor-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav2-vor-ident" );
-	    }
-	    FGSimpleSound *sound;
-	    sound = morse.make_ident( nav2_trans_ident, LO_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav2-vor-ident" );
-
-	    if ( globals->get_soundmgr()->exists( "nav2-dme-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav2-dme-ident" );
-	    }
-	    sound = morse.make_ident( nav2_trans_ident, HI_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav2-dme-ident" );
-
-	    int offset = (int)(sg_random() * 30.0);
-	    nav2_play_count = offset / 4;
-	    nav2_last_time = globals->get_time_params()->get_cur_time() -
-		offset;
-	    // cout << "offset = " << offset << " play_count = "
-	    //      << nav2_play_count << " nav2_last_time = "
-	    //      << nav2_last_time << " current time = "
-	    //      << globals->get_time_params()->get_cur_time() << endl;
-#endif
-
-	    // cout << "Found an ils station in range" << endl;
-	    // cout << " id = " << ils.get_locident() << endl;
-	}
-    } else if ( current_navlist->query( lon, lat, elev, nav2_freq, &nav ) ) {
-	nav2_ident = nav.get_ident();
-	nav2_valid = true;
-	if ( last_nav2_ident != nav2_ident || !last_nav2_vor ) {
-	    last_nav2_ident = nav2_ident;
-	    last_nav2_vor = true;
-	    nav2_trans_ident = nav.get_trans_ident();
-	    nav2_loc = false;
-	    nav2_has_dme = nav.get_has_dme();
-	    nav2_has_dme = false;
-	    nav2_loclon = nav.get_lon();
-	    nav2_loclat = nav.get_lat();
-	    nav2_elev = nav.get_elev();
-	    nav2_magvar = nav.get_magvar();
-	    nav2_range = nav.get_range();
-	    nav2_effective_range = adjustNavRange(nav2_elev, elev, nav2_range);
-	    nav2_target_gs = 0.0;
-	    nav2_radial = nav2_sel_radial;
-	    nav2_x = nav.get_x();
-	    nav2_y = nav.get_y();
-	    nav2_z = nav.get_z();
-
-#ifdef ENABLE_AUDIO_SUPPORT
-	    if ( globals->get_soundmgr()->exists( "nav2-vor-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav2-vor-ident" );
-	    }
-	    FGSimpleSound *sound;
-	    sound = morse.make_ident( nav2_trans_ident, LO_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav2-vor-ident" );
-
-	    if ( globals->get_soundmgr()->exists( "nav2-dme-ident" ) ) {
-		globals->get_soundmgr()->remove( "nav2-dme-ident" );
-	    }
-	    sound = morse.make_ident( nav2_trans_ident, HI_FREQUENCY );
-	    sound->set_volume( 0.3 );
-	    globals->get_soundmgr()->add( sound, "nav2-dme-ident" );
-
-	    int offset = (int)(sg_random() * 30.0);
-	    nav2_play_count = offset / 4;
-	    nav2_last_time = globals->get_time_params()->get_cur_time() -
-		offset;
-	    // cout << "offset = " << offset << " play_count = "
-	    //      << nav2_play_count << " nav2_last_time = "
-	    //      << nav2_last_time << " current time = "
-	    //      << globals->get_time_params()->get_cur_time() << endl;
-#endif
-
-	    // cout << "Found a vor station in range" << endl;
-	    // cout << " id = " << nav.get_ident() << endl;
-	}
-    } else {
-	nav2_valid = false;
-	nav2_ident = "";
-	nav2_radial = 0;
-	nav2_trans_ident = "";
-	last_nav2_ident = "";
-#ifdef ENABLE_AUDIO_SUPPORT
-	globals->get_soundmgr()->remove( "nav2-vor-ident" );
-	globals->get_soundmgr()->remove( "nav2-dme-ident" );
-#endif
-	// cout << "not picking up vor1. :-(" << endl;
-    }
-
+    navcom1.search();
+    navcom2.search();
 
     ////////////////////////////////////////////////////////////////////////
     // DME
@@ -1091,163 +500,8 @@ void FGRadioStack::search()
     }
     last_beacon = beacon_type;
 
+    navcom1.search();
+    navcom2.search();
     adf.search();
     xponder.search();
 }
-
-
-// return the amount of heading needle deflection, returns a value
-// clamped to the range of ( -10 , 10 )
-double FGRadioStack::get_nav1_heading_needle_deflection() const {
-    double r;
-
-    if ( nav1_inrange ) {
-        r = nav1_heading - nav1_radial;
-	// cout << "Radial = " << nav1_radial 
-	//      << "  Bearing = " << nav1_heading << endl;
-    
-	while ( r >  180.0 ) { r -= 360.0;}
-	while ( r < -180.0 ) { r += 360.0;}
-	if ( fabs(r) > 90.0 ) {
-	    r = ( r<0.0 ? -r-180.0 : -r+180.0 );
-	    if ( nav1_loc ) {
-		r = -r;
-	    }
-	}
-
-	// According to Robin Peel, the ILS is 4x more sensitive than a vor
-	if ( nav1_loc ) { r *= 4.0; }
-	if ( r < -10.0 ) { r = -10.0; }
-	if ( r >  10.0 ) { r = 10.0; }
-    } else {
-	r = 0.0;
-    }
-
-    return r;
-}
-
-// return the amount of heading needle deflection, returns a value
-// clamped to the range of ( -10 , 10 )
-double FGRadioStack::get_nav2_heading_needle_deflection() const {
-    double r;
-
-    if ( nav2_inrange ) {
-        r = nav2_heading - nav2_radial;
-	// cout << "Radial = " << nav2_radial 
-	//      << "  Bearing = " << nav2_heading << endl;
-    
-	while (r> 180.0) r-=360.0;
-	while (r<-180.0) r+=360.0;
-	if ( fabs(r) > 90.0 )
-	    r = ( r<0.0 ? -r-180.0 : -r+180.0 );
-	// According to Robin Peel, the ILS is 4x more sensitive than a vor
-	if ( nav2_loc ) r *= 4.0;
-	if ( r < -10.0 ) r = -10.0;
-	if ( r > 10.0 ) r = 10.0;
-    } else {
-	r = 0.0;
-    }
-
-    return r;
-}
-
-// return the amount of glide slope needle deflection (.i.e. the
-// number of degrees we are off the glide slope * 5.0
-double FGRadioStack::get_nav1_gs_needle_deflection() const {
-    if ( nav1_inrange && nav1_has_gs ) {
-	double x = nav1_gs_dist;
-	double y = (fgGetDouble("/position/altitude-ft") - nav1_elev)
-            * SG_FEET_TO_METER;
-	double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
-	return (nav1_target_gs - angle) * 5.0;
-    } else {
-	return 0.0;
-    }
-}
-
-
-// return the amount of glide slope needle deflection (.i.e. the
-// number of degrees we are off the glide slope * 5.0
-double FGRadioStack::get_nav2_gs_needle_deflection() const {
-    if ( nav2_inrange && nav2_has_gs ) {
-	double x = nav2_gs_dist;
-	double y = (fgGetDouble("/position/altitude-ft") - nav2_elev)
-            * SG_FEET_TO_METER;
-	double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
-	return (nav2_target_gs - angle) * 5.0;
-    } else {
-	return 0.0;
-    }
-}
-
-
-/**
- * Return true if the NAV1 TO flag should be active.
- */
-bool 
-FGRadioStack::get_nav1_to_flag () const
-{
-  if (nav1_inrange) {
-    double offset = fabs(nav1_heading - nav1_radial);
-    if (nav1_loc)
-      return true;
-    else
-      return (offset <= 90.0 || offset >= 270.0);
-  } else {
-    return false;
-  }
-}
-
-
-/**
- * Return true if the NAV1 FROM flag should be active.
- */
-bool
-FGRadioStack::get_nav1_from_flag () const
-{
-  if (nav1_inrange) {
-    double offset = fabs(nav1_heading - nav1_radial);
-    if (nav1_loc)
-      return false;
-    else
-      return (offset > 90.0 && offset < 270.0);
-  } else {
-    return false;
-  }
-}
-
-
-/**
- * Return true if the NAV2 TO flag should be active.
- */
-bool 
-FGRadioStack::get_nav2_to_flag () const
-{
-  if (nav2_inrange) {
-    double offset = fabs(nav2_heading - nav2_radial);
-    if (nav2_loc)
-      return true;
-    else
-      return (offset <= 90.0 || offset >= 270.0);
-  } else {
-    return false;
-  }
-}
-
-
-/**
- * Return true if the NAV2 FROM flag should be active.
- */
-bool
-FGRadioStack::get_nav2_from_flag () const
-{
-  if (nav2_inrange) {
-    double offset = fabs(nav2_heading - nav2_radial);
-    if (nav2_loc)
-      return false;
-    else
-      return (offset > 90.0 && offset < 270.0);
-  } else {
-    return false;
-  }
-}
diff --git a/src/Cockpit/radiostack.hxx b/src/Cockpit/radiostack.hxx
index eb4c32e0a..b93542331 100644
--- a/src/Cockpit/radiostack.hxx
+++ b/src/Cockpit/radiostack.hxx
@@ -40,6 +40,7 @@
 
 #include "kr_87.hxx"            // ADF
 #include "kt_70.hxx"            // Transponder
+#include "navcom.hxx"
 
 class FGRadioStack : public FGSubsystem
 {
@@ -56,102 +57,6 @@ class FGRadioStack : public FGSubsystem
 
     bool need_update;
 
-    string comm1_ident;
-    bool comm1_valid;
-    bool comm1_inrange;
-    double comm1_freq;
-    double comm1_alt_freq;
-    double comm1_vol_btn;
-    bool comm1_ident_btn;
-    double comm1_x;
-    double comm1_y;
-    double comm1_z;
-    double comm1_dist;
-    double comm1_elev;
-    double comm1_range;
-    double comm1_effective_range;
-
-    string comm2_ident;
-    bool comm2_valid;
-    bool comm2_inrange;
-    double comm2_freq;
-    double comm2_alt_freq;
-    double comm2_vol_btn;
-    bool comm2_ident_btn;
-    double comm2_x;
-    double comm2_y;
-    double comm2_z;
-    double comm2_dist;
-    double comm2_elev;
-    double comm2_range;
-    double comm2_effective_range;
-
-    string nav1_ident;
-    string nav1_trans_ident;
-    bool nav1_valid;
-    bool nav1_inrange;
-    bool nav1_has_dme;
-    bool nav1_has_gs;
-    bool nav1_loc;
-    double nav1_freq;
-    double nav1_alt_freq;
-    double nav1_radial;
-    double nav1_sel_radial;
-    double nav1_loclon;
-    double nav1_loclat;
-    double nav1_x;
-    double nav1_y;
-    double nav1_z;
-    double nav1_loc_dist;
-    double nav1_gslon;
-    double nav1_gslat;
-    double nav1_gs_x;
-    double nav1_gs_y;
-    double nav1_gs_z;
-    double nav1_gs_dist;
-    SGTimeStamp prev_time;
-    SGTimeStamp curr_time;
-    double nav1_elev;
-    double nav1_range;
-    double nav1_effective_range;
-    double nav1_heading;
-    double nav1_target_gs;
-    double nav1_magvar;
-    double nav1_vol_btn;
-    bool nav1_ident_btn;
-
-    string nav2_ident;
-    string nav2_trans_ident;
-    bool nav2_valid;
-    bool nav2_inrange;
-    bool nav2_has_dme;
-    bool nav2_has_gs;
-    bool nav2_loc;
-    double nav2_freq;
-    double nav2_alt_freq;
-    double nav2_radial;
-    double nav2_sel_radial;
-    double nav2_loclon;
-    double nav2_loclat;
-    double nav2_x;
-    double nav2_y;
-    double nav2_z;
-    double nav2_loc_dist;
-    double nav2_gslon;
-    double nav2_gslat;
-    double nav2_gs_x;
-    double nav2_gs_y;
-    double nav2_gs_z;
-    double nav2_gs_dist;
-    double nav2_elev;
-    double nav2_range;
-    double nav2_effective_range;
-    double nav2_heading;
-    double nav2_target_gs;
-    double nav2_magvar;
-    double nav2_vol_btn;
-    bool nav2_ident_btn;
-
     bool dme_valid;
     bool dme_inrange;
     double dme_freq;
@@ -180,6 +85,8 @@ class FGRadioStack : public FGSubsystem
 
     FGKR_87 adf;                // King KR 87 Digital ADF model
     FGKT_70 xponder;            // Bendix/King KT 70 Panel-Mounted Transponder
+    FGNavCom navcom1;
+    FGNavCom navcom2;
 
     // model standard VOR/DME/TACAN service volumes as per AIM 1-1-8
     double adjustNavRange( double stationElev, double aircraftElev,
@@ -202,82 +109,14 @@ public:
     // Update nav/adf radios based on current postition
     void search ();
 
-    // COMM1 Setters
-    inline void set_comm1_freq( double freq ) {
-	comm1_freq = freq; need_update = true;
-    }
-    inline void set_comm1_alt_freq( double freq ) { comm1_alt_freq = freq; }
-    inline void set_comm1_vol_btn( double val ) {
-	if ( val < 0.0 ) val = 0.0;
-	if ( val > 1.0 ) val = 1.0;
-	comm1_vol_btn = val;
-    }
-    inline void set_comm1_ident_btn( bool val ) { comm1_ident_btn = val; }
-
-    // COMM2 Setters
-    inline void set_comm2_freq( double freq ) {
-	comm2_freq = freq; need_update = true;
-    }
-    inline void set_comm2_alt_freq( double freq ) { comm2_alt_freq = freq; }
-    inline void set_comm2_vol_btn( double val ) {
-	if ( val < 0.0 ) val = 0.0;
-	if ( val > 1.0 ) val = 1.0;
-	comm2_vol_btn = val;
-    }
-    inline void set_comm2_ident_btn( bool val ) { comm2_ident_btn = val; }
-
-    // NAV1 Setters
-    inline void set_nav1_freq( double freq ) {
-	nav1_freq = freq; need_update = true;
-    }
-    inline void set_nav1_alt_freq( double freq ) { nav1_alt_freq = freq; }
-    inline void set_nav1_sel_radial( double radial ) {
-	nav1_sel_radial = radial; need_update = true;
-    }
-    inline void set_nav1_vol_btn( double val ) {
-	if ( val < 0.0 ) val = 0.0;
-	if ( val > 1.0 ) val = 1.0;
-	nav1_vol_btn = val;
-    }
-    inline void set_nav1_ident_btn( bool val ) { nav1_ident_btn = val; }
-
-    // NAV2 Setters
-    inline void set_nav2_freq( double freq ) {
-	nav2_freq = freq; need_update = true;
-    }
-    inline void set_nav2_alt_freq( double freq ) { nav2_alt_freq = freq; }
-    inline void set_nav2_sel_radial( double radial ) {
-	nav2_sel_radial = radial; need_update = true;
-    }
-    inline void set_nav2_vol_btn( double val ) {
-	if ( val < 0.0 ) val = 0.0;
-	if ( val > 1.0 ) val = 1.0;
-	nav2_vol_btn = val;
-    }
-    inline void set_nav2_ident_btn( bool val ) { nav2_ident_btn = val; }
+    inline FGNavCom *get_navcom1() { return &navcom1; }
+    inline FGNavCom *get_navcom2() { return &navcom2; }
 
     // DME Setters
     inline void set_dme_freq (double freq) {
         dme_freq = freq; need_update = true;
     }
 
-    // COMM1 Accessors
-    inline double get_comm1_freq () const { return comm1_freq; }
-    inline double get_comm1_alt_freq () const { return comm1_alt_freq; }
-
-    // COMM2 Accessors
-    inline double get_comm2_freq () const { return comm2_freq; }
-    inline double get_comm2_alt_freq () const { return comm2_alt_freq; }
-
-    // NAV1 Accessors
-    inline double get_nav1_freq () const { return nav1_freq; }
-    inline double get_nav1_alt_freq () const { return nav1_alt_freq; }
-    inline double get_nav1_sel_radial() const { return nav1_sel_radial; }
-
-    // NAV2 Accessors
-    inline double get_nav2_freq () const { return nav2_freq; }
-    inline double get_nav2_alt_freq () const { return nav2_alt_freq; }
-    inline double get_nav2_sel_radial() const { return nav2_sel_radial; }
 
     // DME Accessors
     inline double get_dme_freq () const { return dme_freq; }
@@ -288,64 +127,6 @@ public:
     inline bool get_outer_blink () const { return outer_blink; }
 
     // Calculated values.
-    inline bool get_comm1_inrange() const { return comm1_inrange; }
-    inline double get_comm1_vol_btn() const { return comm1_vol_btn; }
-    inline bool get_comm1_ident_btn() const { return comm1_ident_btn; }
-
-    inline bool get_comm2_inrange() const { return comm2_inrange; }
-    inline double get_comm2_vol_btn() const { return comm2_vol_btn; }
-    inline bool get_comm2_ident_btn() const { return comm2_ident_btn; }
-
-    inline bool get_nav1_inrange() const { return nav1_inrange; }
-    bool get_nav1_to_flag () const;
-    bool get_nav1_from_flag () const;
-    inline bool get_nav1_has_dme() const { return nav1_has_dme; }
-    inline bool get_nav1_dme_inrange () const {
-	return nav1_inrange && nav1_has_dme;
-    }
-    inline bool get_nav1_has_gs() const { return nav1_has_gs; }
-    inline bool get_nav1_loc() const { return nav1_loc; }
-    inline double get_nav1_loclon() const { return nav1_loclon; }
-    inline double get_nav1_loclat() const { return nav1_loclat; }
-    inline double get_nav1_loc_dist() const { return nav1_loc_dist; }
-    inline double get_nav1_gslon() const { return nav1_gslon; }
-    inline double get_nav1_gslat() const { return nav1_gslat; }
-    inline double get_nav1_gs_dist() const { return nav1_gs_dist; }
-    inline double get_nav1_elev() const { return nav1_elev; }
-    inline double get_nav1_heading() const { return nav1_heading; }
-    inline double get_nav1_radial() const { return nav1_radial; }
-    inline double get_nav1_target_gs() const { return nav1_target_gs; }
-    inline double get_nav1_magvar() const { return nav1_magvar; }
-    double get_nav1_heading_needle_deflection() const;
-    double get_nav1_gs_needle_deflection() const;
-    inline double get_nav1_vol_btn() const { return nav1_vol_btn; }
-    inline bool get_nav1_ident_btn() const { return nav1_ident_btn; }
-
-    inline bool get_nav2_inrange() const { return nav2_inrange; }
-    bool get_nav2_to_flag () const;
-    bool get_nav2_from_flag () const;
-    inline bool get_nav2_has_dme() const { return nav2_has_dme; }
-    inline bool get_nav2_dme_inrange () const {
-	return nav2_inrange && nav2_has_dme;
-    }
-    inline bool get_nav2_has_gs() const { return nav2_has_gs; }
-    inline bool get_nav2_loc() const { return nav2_loc; }
-    inline double get_nav2_loclon() const { return nav2_loclon; }
-    inline double get_nav2_loclat() const { return nav2_loclat; }
-    inline double get_nav2_loc_dist() const { return nav2_loc_dist; }
-    inline double get_nav2_gslon() const { return nav2_gslon; }
-    inline double get_nav2_gslat() const { return nav2_gslat; }
-    inline double get_nav2_gs_dist() const { return nav2_gs_dist; }
-    inline double get_nav2_elev() const { return nav2_elev; }
-    inline double get_nav2_heading() const { return nav2_heading; }
-    inline double get_nav2_radial() const { return nav2_radial; }
-    inline double get_nav2_target_gs() const { return nav2_target_gs; }
-    inline double get_nav2_magvar() const { return nav2_magvar; }
-    double get_nav2_heading_needle_deflection() const;
-    double get_nav2_gs_needle_deflection() const;
-    inline double get_nav2_vol_btn() const { return nav2_vol_btn; }
-    inline bool get_nav2_ident_btn() const { return nav2_ident_btn; }
-
     inline bool get_dme_inrange () const { return dme_inrange; }
     inline double get_dme_dist () const { return dme_dist; }
     inline double get_dme_spd () const { return dme_spd; }
diff --git a/src/Cockpit/steam.cxx b/src/Cockpit/steam.cxx
index 4bc4fe6e7..e5f058407 100644
--- a/src/Cockpit/steam.cxx
+++ b/src/Cockpit/steam.cxx
@@ -494,12 +494,12 @@ void FGSteam::_CatchUp()
 
 double FGSteam::get_HackOBS1_deg () const
 {
-  return current_radiostack->get_nav1_radial(); 
+    return current_radiostack->get_navcom1()->get_nav_radial(); 
 }
 
 double FGSteam::get_HackOBS2_deg () const
 {
-    return current_radiostack->get_nav2_radial(); 
+    return current_radiostack->get_navcom2()->get_nav_radial(); 
 }