diff --git a/Aircraft/Instruments/KAP140TwoAxis.xml b/Aircraft/Instruments/KAP140TwoAxis.xml
index 75b7cfd24..ca85a0ef8 100644
--- a/Aircraft/Instruments/KAP140TwoAxis.xml
+++ b/Aircraft/Instruments/KAP140TwoAxis.xml
@@ -220,6 +220,93 @@ properties' values.
    </transformations>
   </layer>
 
+  <layer>
+   <name>APR-ARM Anunciator</name>
+   <condition>
+    <equals>
+     <property>/autopilot/KAP140/annunciators/apr-arm</property>
+     <value>on</value>
+    </equals>
+   </condition>
+   <texture>
+    <path>Aircraft/Instruments/Textures/KAP140.rgb</path>
+    <x1>0.13671875</x1>
+    <x2>0.265625</x2>
+    <y1>0.939453125</y1>
+    <y2>1.0</y2>
+   </texture>
+   <w>64</w>
+   <h>30</h>
+   <transformations>
+    <transformation>
+     <type>x-shift</type>
+     <offset>-145</offset>
+    </transformation>
+    <transformation>
+     <type>y-shift</type>
+     <offset>15</offset>
+    </transformation>
+   </transformations>
+  </layer>
+
+<layer>
+   <name>REV Anunciator</name>
+   <condition>
+    <equals>
+     <property>/autopilot/KAP140/annunciators/rev</property>
+     <value>on</value>
+    </equals>
+   </condition>
+   <texture>
+    <path>Aircraft/Instruments/Textures/KAP140.rgb</path>
+    <x1>0.4375</x1>
+    <x2>0.54296875</x2>
+    <y1>0.802734375</y1>
+    <y2>0.845703125</y2>
+   </texture>
+   <w>53</w>
+   <h>21</h>
+   <transformations>
+    <transformation>
+     <type>x-shift</type>
+     <offset>-150</offset>
+    </transformation>
+    <transformation>
+     <type>y-shift</type>
+     <offset>40</offset>
+    </transformation>
+   </transformations>
+  </layer>
+
+  <layer>
+   <name>REV-ARM Anunciator</name>
+   <condition>
+    <equals>
+     <property>/autopilot/KAP140/annunciators/rev-arm</property>
+     <value>on</value>
+    </equals>
+   </condition>
+   <texture>
+    <path>Aircraft/Instruments/Textures/KAP140.rgb</path>
+    <x1>0.2734375</x1>
+    <x2>0.40234375</x2>
+    <y1>0.939453125</y1>
+    <y2>1.0</y2>
+   </texture>
+   <w>64</w>
+   <h>30</h>
+   <transformations>
+    <transformation>
+     <type>x-shift</type>
+     <offset>-145</offset>
+    </transformation>
+    <transformation>
+     <type>y-shift</type>
+     <offset>15</offset>
+    </transformation>
+   </transformations>
+  </layer>
+
   <layer>
    <name>VS Anunciator</name>
    <condition>
@@ -343,6 +430,64 @@ properties' values.
    </transformations>
   </layer>
 
+  <layer>
+   <name>GS Anunciator</name>
+   <condition>
+    <equals>
+     <property>/autopilot/KAP140/annunciators/gs</property>
+     <value>on</value>
+    </equals>
+   </condition>
+   <texture>
+    <path>Aircraft/Instruments/Textures/KAP140.rgb</path>
+    <x1>0.791015625</x1>
+    <x2>0.85546875</x2>
+    <y1>0.802734375</y1>
+    <y2>0.845703125</y2>
+   </texture>
+   <w>31</w>
+   <h>21</h>
+   <transformations>
+    <transformation>
+     <type>x-shift</type>
+     <offset>-47</offset>
+    </transformation>
+    <transformation>
+     <type>y-shift</type>
+     <offset>40</offset>
+    </transformation>
+   </transformations>
+  </layer>
+
+  <layer>
+   <name>GS-ARM Anunciator</name>
+   <condition>
+    <equals>
+     <property>/autopilot/KAP140/annunciators/gs-arm</property>
+     <value>on</value>
+    </equals>
+   </condition>
+   <texture>
+    <path>Aircraft/Instruments/Textures/KAP140.rgb</path>
+    <x1>0.548828125</x1>
+    <x2>0.640625</x2>
+    <y1>0.939453125</y1>
+    <y2>1.0</y2>
+   </texture>
+   <w>45</w>
+   <h>30</h>
+   <transformations>
+    <transformation>
+     <type>x-shift</type>
+     <offset>-136</offset>
+    </transformation>
+    <transformation>
+     <type>y-shift</type>
+     <offset>15</offset>
+    </transformation>
+   </transformations>
+  </layer>
+
  </layers>
 
 <!-- Actions -->
@@ -424,6 +569,21 @@ properties' values.
    </binding>
   </action>
 
+  <action>
+   <name>REV Button</name>
+   <button>0</button>
+   <x>30</x>
+   <y>-54</y>
+   <w>30</w>
+   <h>20</h>
+   <binding>
+    <command>nasal</command>
+     <script>
+      kap140.rev_button();
+     </script>
+   </binding>
+  </action>
+
   <action>
    <name>DN Button</name>
    <button>0</button>
diff --git a/Aircraft/c172p/Systems/KAP140.xml b/Aircraft/c172p/Systems/KAP140.xml
index 5d35caa50..99ab55f42 100644
--- a/Aircraft/c172p/Systems/KAP140.xml
+++ b/Aircraft/c172p/Systems/KAP140.xml
@@ -32,12 +32,12 @@
       <prop>/autopilot/KAP140/settings/target-intercept-angle</prop>
     </output>
     <config>
-      <Kp>7.0</Kp>        <!-- proportional gain -->
+      <Kp>2.0</Kp>        <!-- proportional gain -->
       <beta>1.0</beta>    <!-- input value weighing factor -->
       <alpha>0.1</alpha>  <!-- low pass filter weighing factor -->
       <gamma>0.0</gamma>  <!-- input value weighing factor for -->
                           <!-- unfiltered derivative error -->
-      <Ti>10.0</Ti>       <!-- integrator time -->
+      <Ti>15.0</Ti>       <!-- integrator time -->
       <Td>0.0</Td>    <!-- derivator time -->
       <u_min>-45.0</u_min> <!-- minimum output clamp -->
       <u_max>45.0</u_max>  <!-- maximum output clamp -->
@@ -47,7 +47,7 @@
   <!-- Approach hold (APR) Mode-->
   <pid-controller>
     <name>Approach hold (APR) Mode</name>
-    <debug>true</debug>
+    <debug>false</debug>
     <enable>
       <prop>/autopilot/KAP140/locks/apr-hold</prop>
       <value>apr</value>
@@ -62,12 +62,43 @@
       <prop>/autopilot/KAP140/settings/target-intercept-angle</prop>
     </output>
     <config>
-      <Kp>7.0</Kp>        <!-- proportional gain -->
+      <Kp>2.0</Kp>        <!-- proportional gain -->
       <beta>1.0</beta>    <!-- input value weighing factor -->
       <alpha>0.1</alpha>  <!-- low pass filter weighing factor -->
       <gamma>0.0</gamma>  <!-- input value weighing factor for -->
                           <!-- unfiltered derivative error -->
-      <Ti>10.0</Ti>       <!-- integrator time -->
+      <Ti>15.0</Ti>       <!-- integrator time -->
+      <Td>0.001</Td>    <!-- derivator time -->
+      <u_min>-45.0</u_min> <!-- minimum output clamp -->
+      <u_max>45.0</u_max>  <!-- maximum output clamp -->
+    </config>
+  </pid-controller>
+
+  <!-- Backcourse hold (REV) Mode-->
+  <pid-controller>
+    <name>Backcourse hold (REV) Mode</name>
+    <debug>false</debug>
+    <enable>
+      <prop>/autopilot/KAP140/locks/rev-hold</prop>
+      <value>rev</value>
+    </enable>
+    <input>
+      <prop>/radios/nav/heading-needle-deflection</prop>
+      <scale>-1.0</scale>
+    </input>
+    <reference>
+      <value>0.0</value>
+    </reference>
+    <output>
+      <prop>/autopilot/KAP140/settings/target-intercept-angle</prop>
+    </output>
+    <config>
+      <Kp>2.0</Kp>        <!-- proportional gain -->
+      <beta>1.0</beta>    <!-- input value weighing factor -->
+      <alpha>0.1</alpha>  <!-- low pass filter weighing factor -->
+      <gamma>0.0</gamma>  <!-- input value weighing factor for -->
+                          <!-- unfiltered derivative error -->
+      <Ti>15.0</Ti>       <!-- integrator time -->
       <Td>0.0</Td>    <!-- derivator time -->
       <u_min>-45.0</u_min> <!-- minimum output clamp -->
       <u_max>45.0</u_max>  <!-- maximum output clamp -->
@@ -84,7 +115,8 @@
       <value>hdg</value>
     </enable>
     <input>
-      <prop>/autopilot/internal/heading-bug-error-deg</prop>
+      <prop>/autopilot/internal/heading-bug-error-deg</prop> -->
+<!--      <prop>/instrumentation/gps/true-bug-error-deg</prop> -->
     </input>
     <reference>
       <prop>/autopilot/KAP140/settings/target-intercept-angle</prop>
@@ -173,7 +205,7 @@
    <!-- Glideslope Hold (GS) Mode --> 
   <pid-controller>
     <name>Glideslope Hold (GS) Mode</name>
-    <debug>true</debug>
+    <debug>false</debug>
     <enable>
       <prop>/autopilot/KAP140/locks/gs-hold</prop>
       <value>gs</value>
diff --git a/Nasal/kap140.nas b/Nasal/kap140.nas
index 88ee1fac7..0296fe5d6 100644
--- a/Nasal/kap140.nas
+++ b/Nasal/kap140.nas
@@ -79,6 +79,7 @@ ap_button = func {
     setprop(Locks, "gs-hold", "off");
     setprop(Locks, "hdg-hold", "off");
     setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "roll-axis", "trn");
     setprop(Locks, "roll-mode", "rol");
     setprop(Locks, "pitch-axis", "vs");
@@ -106,6 +107,7 @@ ap_button = func {
     setprop(Locks, "gs-hold", "off");
     setprop(Locks, "hdg-hold", "off");
     setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "roll-axis", "off");
     setprop(Locks, "roll-mode", "off");
     setprop(Locks, "pitch-axis", "off");
@@ -120,16 +122,19 @@ ap_button = func {
     setprop(Annunciators, "hdg", "off");
     setprop(Annunciators, "nav", "off");
     setprop(Annunciators, "nav-arm", "off");
+    setprop(Annunciators, "apr", "off");
+    setprop(Annunciators, "apr-arm", "off");
+    setprop(Annunciators, "rev", "off");
+    setprop(Annunciators, "rev-arm", "off");
     setprop(Annunciators, "vs", "off");
     setprop(Annunciators, "vs-number", "off");
     setprop(Annunciators, "fpm", "off");
     setprop(Annunciators, "alt", "off");
     setprop(Annunciators, "apr", "off");
     setprop(Annunciators, "gs", "off");
+    setprop(Annunciators, "gs-arm", "off");
 
     flasher("ap", 1.0, 5, "off");
-
-    setprop(Internal, "ft", 0.1);
   }
 }
 
@@ -147,6 +152,7 @@ hdg_button = func {
   {
     setprop(Locks, "alt-hold", "off");
     setprop(Locks, "apr-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "gs-hold", "off");
     setprop(Locks, "hdg-hold", "hdg");
     setprop(Locks, "nav-hold", "off");
@@ -174,10 +180,12 @@ hdg_button = func {
   elsif (getprop(Locks, "roll-mode") == "rol" or
          getprop(Locks, "roll-mode") == "nav" or
 	 getprop(Locks, "roll-mode") == "nav-arm" or
-         getprop(Locks, "roll-mode") == "rev")
+         getprop(Locks, "roll-mode") == "rev" or
+         getprop(Locks, "roll-mode") == "rev-arm")
   {
     #setprop(Locks, "alt-hold", "off");
     setprop(Locks, "apr-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "gs-hold", "off");
     setprop(Locks, "hdg-hold", "hdg");
     setprop(Locks, "nav-hold", "off");
@@ -191,6 +199,7 @@ hdg_button = func {
     setprop(Annunciators, "hdg", "on");
     setprop(Annunciators, "nav", "off");
     setprop(Annunciators, "rol", "off");
+    setprop(Annunciators, "rev", "off");
 
     setprop(Settings, "target-intercept-angle", 0.0);
   }
@@ -204,6 +213,7 @@ hdg_button = func {
     setprop(Locks, "apr-hold", "off");
     setprop(Locks, "gs-hold", "off");
     setprop(Locks, "hdg-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "nav-hold", "off");
     setprop(Locks, "roll-axis", "trn");
     setprop(Locks, "roll-mode", "rol");
@@ -222,8 +232,10 @@ hdg_button = func {
   # If we are in APR mode we also have to change pitch mode.
   # TODO: Should we switch to VS or ALT mode? (currently VS)
   ##
-  elsif (getprop(Locks, "roll-mode") == "apr" and
-         getprop(Locks, "pitch-mode") == "gs")
+  elsif (getprop(Locks, "roll-mode") == "apr" or
+         getprop(Locks, "roll-mode") == "apr-arm" or
+         getprop(Locks, "pitch-mode") == "gs" or
+         getprop(Locks, "pitch-mode") == "gs-arm")
   {
     setprop(Locks, "alt-hold", "off");
     setprop(Locks, "apr-hold", "off");
@@ -236,10 +248,12 @@ hdg_button = func {
     setprop(Locks, "pitch-mode", "vs");
 
     setprop(Annunciators, "alt", "off");
-    setprop(Annunciators, "apr", "off");
-    setprop(Annunciators, "gs", "off");
     setprop(Annunciators, "hdg", "on");
     setprop(Annunciators, "nav", "off");
+    setprop(Annunciators, "apr", "off");
+    setprop(Annunciators, "apr-arm", "off");
+    setprop(Annunciators, "gs", "off");
+    setprop(Annunciators, "gs-arm", "off");
     setprop(Annunciators, "vs", "on");
     setprop(Annunciators, "vs-number", "on");
     setprop(Annunciators, "fpm", "on");
@@ -253,12 +267,17 @@ hdg_button = func {
 
 nav_button = func {
   #print("nav_button");
+
+  ##
+  # If we are in HDG mode we switch to the 45 degree angle intercept NAV mode
+  ##
   if (getprop(Locks, "roll-mode") == "hdg")
   {
     flasher("hdg", 0.5, 8, "off");
       
     setprop(Locks, "apr-hold", "off");
     setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "hdg-hold", "hdg");
     setprop(Locks, "nav-hold", "off");
     setprop(Locks, "roll-axis", "trn");
@@ -266,12 +285,16 @@ nav_button = func {
 
     nav_arm_from_hdg();
   }
+  ##
+  # If we are in ROL mode we switch to the all angle intercept NAV mode.
+  ##
   elsif (getprop(Locks, "roll-mode") == "rol")
   {
     flasher("hdg", 0.5, 8, "off");
 
     setprop(Locks, "apr-hold", "off");
     setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "hdg-hold", "off");
     setprop(Locks, "nav-hold", "off");
     setprop(Locks, "roll-axis", "trn");
@@ -279,26 +302,19 @@ nav_button = func {
 
     nav_arm_from_rol();
   }
-  elsif (getprop(Locks, "roll-mode") == "apr" and
-         getprop(Locks, "pitch-mode") == "gs")
-  {
-    setprop(Locks, "alt-hold", "off");
-    setprop(Locks, "apr-hold", "off");
-    setprop(Locks, "gs-hold", "off");
-    setprop(Locks, "hdg-hold", "hdg");
-    setprop(Locks, "nav-hold", "nav");
-    setprop(Locks, "roll-axis", "trn");
-    setprop(Locks, "roll-mode", "nav");
-    setprop(Locks, "pitch-axis", "vs");
-    setprop(Locks, "pitch-mode", "vs");
-
-    setprop(Settings, "target-pressure-rate", getprop(Internal,
-    "pressure-rate"));
-  }
+  ##
+  # TODO:
+  # NAV mode can only be armed if we are in HDG or ROL mode.
+  # Can anyone verify that this is correct?
+  ##
 }
 
 nav_arm_from_hdg = func
 {
+  ##
+  # Abort the NAV-ARM mode if something has changed the roll mode to something
+  # else than NAV-ARM.
+  ##
   if (getprop(Locks, "roll-mode") != "nav-arm")
   {
     setprop(Annunciators, "nav-arm", "off");
@@ -306,21 +322,33 @@ nav_arm_from_hdg = func
   }
 
   setprop(Annunciators, "nav-arm", "on");
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
   if (flash_timer > -0.5)
   {
     print("flashing...");
     settimer(nav_arm_from_hdg, 2.5);
     return;
   }
-
+  ##
+  # Activate the nav-hold controller and check the needle deviation.
+  ##
   setprop(Locks, "nav-hold", "nav");
   deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
   if (abs(deviation) > 3.0)
   {
     print("deviation");
     settimer(nav_arm_from_hdg, 5);
     return;
   }
+  ##
+  # If the deviation is less than 3 degrees turn of the NAV-ARM annunciator
+  # and show the NAV annunciator. End of NAV-ARM sequence.
+  ##
   elsif (abs(deviation) < 3.1)
   {
     print("capture");
@@ -331,12 +359,18 @@ nav_arm_from_hdg = func
 
 nav_arm_from_rol = func
 {
+  ##
+  # Abort the NAV-ARM mode if something has changed the roll mode to something
+  # else than NAV-ARM.
+  ##
   if (getprop(Locks, "roll-mode") != "nav-arm")
   {
     setprop(Annunciators, "nav-arm", "off");
     return;
   }
-
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
   setprop(Annunciators, "nav-arm", "on");
   if (flash_timer > -0.5)
   {
@@ -345,17 +379,26 @@ nav_arm_from_rol = func
     settimer(nav_arm_from_rol, 2.5);
     return;
   }
-
+  ##
+  # Turn the ROL annunciator back on and activate the ROL mode.
+  ##
   setprop(Annunciators, "rol", "on");
   setprop(Locks, "roll-axis", "trn");
   setprop(Settings, "target-turn-rate", 0.0);
   deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
   if (abs(deviation) > 3.0)
   {
     print("deviation");
     settimer(nav_arm_from_rol, 5);
     return;
   }
+  ##
+  # If the deviation is less than 3 degrees turn of the NAV-ARM annunciator
+  # and show the NAV annunciator. End of NAV-ARM sequence.
+  ##
   elsif (abs(deviation) < 3.1)
   {
     print("capture");
@@ -365,6 +408,7 @@ nav_arm_from_rol = func
 
     setprop(Locks, "apr-hold", "off");
     setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "hdg-hold", "hdg");
     setprop(Locks, "nav-hold", "nav");
     setprop(Locks, "roll-axis", "trn");
@@ -374,37 +418,360 @@ nav_arm_from_rol = func
 
 apr_button = func {
   #print("apr_button");
-  if (getprop(Locks, "roll-mode") == "hdg" or
-      getprop(Locks, "roll-mode") == "rol" or
-      getprop(Locks, "roll-mode") == "rev" or
-      #getprop(Locks, "roll-mode") == "apr" or
-      getprop(Locks, "pitch-mode") == "nav")
+  ##
+  # If we are in HDG mode we switch to the 45 degree intercept angle APR mode
+  ##
+  if (getprop(Locks, "roll-mode") == "hdg")
   {
-    setprop(Locks, "alt-hold", "off");
+    flasher("hdg", 0.5, 8, "off");
+
+    #setprop(Locks, "alt-hold", "off");
     setprop(Locks, "apr-hold", "apr");
-    setprop(Locks, "gs-hold", "gs");
+    setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
+    setprop(Locks, "hdg-hold", "hdg");
+    setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "roll-axis", "trn");
+    setprop(Locks, "roll-mode", "apr-arm");
+    #setprop(Locks, "pitch-axis", "vs");
+    #setprop(Locks, "pitch-mode", "gs");
+
+    apr_arm_from_hdg();
+  }
+  elsif (getprop(Locks, "roll-mode") == "rol")
+  {
+    flasher("hdg", 0.5, 8, "off");
+
+    #setprop(Locks, "alt-hold", "off");
+    setprop(Locks, "apr-hold", "off");
+    setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "hdg-hold", "off");
     setprop(Locks, "nav-hold", "off");
     setprop(Locks, "roll-axis", "trn");
-    setprop(Locks, "roll-mode", "apr");
-    setprop(Locks, "pitch-axis", "vs");
-    setprop(Locks, "pitch-mode", "gs");
+    setprop(Locks, "roll-mode", "apr-arm");
+    #setprop(Locks, "pitch-axis", "vs");
+    #setprop(Locks, "pitch-mode", "vs");
+
+    apr_arm_from_rol();
   }
-  elsif (getprop(Locks, "roll-mode") == "apr" and
-         getprop(Locks, "pitch-mode") == "gs")
+}
+
+apr_arm_from_hdg = func
+{
+  ##
+  # Abort the APR-ARM mode if something has changed the roll mode to something
+  # else than APR-ARM.
+  ##
+  if (getprop(Locks, "roll-mode") != "apr-arm")
   {
+    setprop(Annunciators, "apr-arm", "off");
+    return;
+  }
+
+  setprop(Annunciators, "apr-arm", "on");
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
+  if (flash_timer > -0.5)
+  {
+    print("flashing...");
+    settimer(apr_arm_from_hdg, 2.5);
+    return;
+  }
+  ##
+  # Activate the apr-hold controller and check the needle deviation.
+  ##
+  setprop(Locks, "apr-hold", "apr");
+  deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
+  if (abs(deviation) > 3.0)
+  {
+    print("deviation");
+    settimer(apr_arm_from_hdg, 5);
+    return;
+  }
+  ##
+  # If the deviation is less than 3 degrees turn of the APR-ARM annunciator
+  # and show the APR annunciator. End of APR-ARM sequence. Start the GS-ARM
+  # sequence.
+  ##
+  elsif (abs(deviation) < 3.1)
+  {
+    print("capture");
+    setprop(Annunciators, "apr-arm", "off");
+    setprop(Annunciators, "apr", "on");
+    setprop(Locks, "pitch-mode", "gs-arm");
+
+    gs_arm();
+  }
+}
+
+apr_arm_from_rol = func
+{
+  ##
+  # Abort the APR-ARM mode if something has changed the roll mode to something
+  # else than APR-ARM.
+  ##
+  if (getprop(Locks, "roll-mode") != "apr-arm")
+  {
+    setprop(Annunciators, "apr-arm", "off");
+    return;
+  }
+
+  setprop(Annunciators, "apr-arm", "on");
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
+  if (flash_timer > -0.5)
+  {
+    print("flashing...");
+    setprop(Annunciators, "rol", "off");
+    settimer(apr_arm_from_rol, 2.5);
+    return;
+  }
+  ##
+  # Turn the ROL annunciator back on and activate the ROL mode.
+  ##
+  setprop(Annunciators, "rol", "on");
+  setprop(Locks, "roll-axis", "trn");
+  setprop(Settings, "target-turn-rate", 0.0);
+  deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
+  if (abs(deviation) > 3.0)
+  {
+    print("deviation");
+    settimer(apr_arm_from_rol, 5);
+    return;
+  }
+  ##
+  # If the deviation is less than 3 degrees turn of the APR-ARM annunciator
+  # and show the APR annunciator. End of APR-ARM sequence. Start the GS-ARM
+  # sequence.
+  ##
+  elsif (abs(deviation) < 3.1)
+  {
+    print("capture");
+    setprop(Annunciators, "rol", "off");
+    setprop(Annunciators, "apr-arm", "off");
+    setprop(Annunciators, "apr", "on");
+
+    setprop(Locks, "apr-hold", "apr");
+    setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
+    setprop(Locks, "hdg-hold", "hdg");
+    setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "roll-axis", "trn");
+    setprop(Locks, "roll-mode", "apr");
+    setprop(Locks, "pitch-mode", "gs-arm");
+
+    gs_arm();
+  }
+}
+
+
+gs_arm = func {
+  ##
+  # Abort the GS-ARM mode if something has changed the pitch mode to something
+  # else than GS-ARM.
+  ##
+  if (getprop(Locks, "pitch-mode") != "gs-arm")
+  {
+    setprop(Annunciators, "gs-arm", "off");
+    return;
+  }
+
+  setprop(Annunciators, "gs-arm", "on");
+
+  deviation = getprop("/radios/nav/gs-needle-deflection");
+  ##
+  # If the deflection is more than 1 degrees wait 5 seconds and check again.
+  ##
+  if (abs(deviation) > 1.0)
+  {
+    print("deviation");
+    settimer(gs_arm, 5);
+    return;
+  }
+  ##
+  # If the deviation is less than 3 degrees turn off the GS-ARM annunciator
+  # and show the GS annunciator. Activate the GS pitch mode.
+  ##
+  elsif (abs(deviation) < 3.1)
+  {
+    print("capture");
+    setprop(Annunciators, "alt", "off");
+    setprop(Annunciators, "vs", "off");
+    setprop(Annunciators, "vs-number", "off");
+    setprop(Annunciators, "fpm", "off");
+    setprop(Annunciators, "gs-arm", "off");
+    setprop(Annunciators, "gs", "on");
+
     setprop(Locks, "alt-hold", "off");
+    setprop(Locks, "gs-hold", "gs");
+    setprop(Locks, "pitch-mode", "gs");
+    #setprop(Locks, "hdg-hold", "hdg");
+    #setprop(Locks, "nav-hold", "off");
+    #setprop(Locks, "roll-axis", "trn");
+    #setprop(Locks, "roll-mode", "apr");
+  }
+
+}
+
+
+rev_button = func {
+  #print("rev_button");
+  ##
+  # If we are in HDG mode we switch to the 45 degree intercept angle REV mode
+  ##
+  if (getprop(Locks, "roll-mode") == "hdg")
+  {
+    flasher("hdg", 0.5, 8, "off");
+
+    #setprop(Locks, "alt-hold", "off");
     setprop(Locks, "apr-hold", "off");
     setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
     setprop(Locks, "hdg-hold", "hdg");
-    setprop(Locks, "nav-hold", "nav");
+    setprop(Locks, "nav-hold", "off");
     setprop(Locks, "roll-axis", "trn");
-    setprop(Locks, "roll-mode", "nav");
-    setprop(Locks, "pitch-axis", "vs");
-    setprop(Locks, "pitch-mode", "vs");
+    setprop(Locks, "roll-mode", "rev-arm");
+    #setprop(Locks, "pitch-axis", "vs");
+    #setprop(Locks, "pitch-mode", "gs");
 
-    setprop(Settings, "target-pressure-rate", getprop(Internal,
-    "pressure-rate"));
+    rev_arm_from_hdg();
+  }
+  elsif (getprop(Locks, "roll-mode") == "rol")
+  {
+    flasher("hdg", 0.5, 8, "off");
+
+    #setprop(Locks, "alt-hold", "off");
+    setprop(Locks, "apr-hold", "off");
+    setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "off");
+    setprop(Locks, "hdg-hold", "off");
+    setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "roll-axis", "trn");
+    setprop(Locks, "roll-mode", "rev-arm");
+    #setprop(Locks, "pitch-axis", "vs");
+    #setprop(Locks, "pitch-mode", "vs");
+
+    rev_arm_from_rol();
+  }
+}
+
+
+rev_arm_from_hdg = func
+{
+  ##
+  # Abort the REV-ARM mode if something has changed the roll mode to something
+  # else than REV-ARM.
+  ##
+  if (getprop(Locks, "roll-mode") != "rev-arm")
+  {
+    setprop(Annunciators, "rev-arm", "off");
+    return;
+  }
+
+  setprop(Annunciators, "rev-arm", "on");
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
+  if (flash_timer > -0.5)
+  {
+    print("flashing...");
+    settimer(rev_arm_from_hdg, 2.5);
+    return;
+  }
+  ##
+  # Activate the rev-hold controller and check the needle deviation.
+  ##
+  setprop(Locks, "rev-hold", "rev");
+  deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
+  if (abs(deviation) > 3.0)
+  {
+    print("deviation");
+    settimer(rev_arm_from_hdg, 5);
+    return;
+  }
+  ##
+  # If the deviation is less than 3 degrees turn of the REV-ARM annunciator
+  # and show the REV annunciator. End of REV-ARM sequence.
+  ##
+  elsif (abs(deviation) < 3.1)
+  {
+    print("capture");
+    setprop(Annunciators, "rev-arm", "off");
+    setprop(Annunciators, "rev", "on");
+  }
+}
+
+
+rev_arm_from_rol = func
+{
+  ##
+  # Abort the REV-ARM mode if something has changed the roll mode to something
+  # else than REV-ARM.
+  ##
+  if (getprop(Locks, "roll-mode") != "rev-arm")
+  {
+    setprop(Annunciators, "rev-arm", "off");
+    return;
+  }
+
+  setprop(Annunciators, "rev-arm", "on");
+  ##
+  # Wait for the HDG annunciator flashing to finish.
+  ##
+  if (flash_timer > -0.5)
+  {
+    print("flashing...");
+    setprop(Annunciators, "rol", "off");
+    settimer(rev_arm_from_rol, 2.5);
+    return;
+  }
+  ##
+  # Turn the ROL annunciator back on and activate the ROL mode.
+  ##
+  setprop(Annunciators, "rol", "on");
+  setprop(Locks, "roll-axis", "trn");
+  setprop(Settings, "target-turn-rate", 0.0);
+  deviation = getprop("/radios/nav/heading-needle-deflection");
+  ##
+  # If the deflection is more than 3 degrees wait 5 seconds and check again.
+  ##
+  if (abs(deviation) > 3.0)
+  {
+    print("deviation");
+    settimer(rev_arm_from_rol, 5);
+    return;
+  }
+  ##
+  # If the deviation is less than 3 degrees turn of the REV-ARM annunciator
+  # and show the REV annunciator. End of REV-ARM sequence.
+  ##
+  elsif (abs(deviation) < 3.1)
+  {
+    print("capture");
+    setprop(Annunciators, "rol", "off");
+    setprop(Annunciators, "rev-arm", "off");
+    setprop(Annunciators, "rev", "on");
+
+    setprop(Locks, "apr-hold", "off");
+    setprop(Locks, "gs-hold", "off");
+    setprop(Locks, "rev-hold", "rev");
+    setprop(Locks, "hdg-hold", "hdg");
+    setprop(Locks, "nav-hold", "off");
+    setprop(Locks, "roll-axis", "trn");
+    setprop(Locks, "roll-mode", "rev");
+    #setprop(Locks, "pitch-mode", "gs-arm");
   }
 }