diff --git a/Aircraft/ufo/Instruments/instrumentation.xml b/Aircraft/ufo/Instruments/instrumentation.xml
index 370109c94..97e77aace 100644
--- a/Aircraft/ufo/Instruments/instrumentation.xml
+++ b/Aircraft/ufo/Instruments/instrumentation.xml
@@ -123,12 +123,14 @@
 		<number>0</number>
 	</tacan>
 
-	<!-- option stuff - enabled for testing only -->
-<!-- 
 	<mk-viii>
 		<name>mk-viii</name>
 		<number>0</number>
 	</mk-viii>
--->
+
+	<tcas>
+		<name>tcas</name>
+		<number>0</number>
+	</tcas>
 
 </PropertyList>
diff --git a/Aircraft/ufo/ufo-set.xml b/Aircraft/ufo/ufo-set.xml
index 07a453b4f..b92ea5763 100644
--- a/Aircraft/ufo/ufo-set.xml
+++ b/Aircraft/ufo/ufo-set.xml
@@ -629,39 +629,52 @@
 		<nav n="1">
 			<volume type="double">0</volume>
 		</nav>
-		<!-- mk-viii is disabled (enable in instruments.xml for testing purposes) -->
-        <mk-viii>  <!-- mk-viii configuration, see: http://wiki.flightgear.org/index.php/GPWS -->
-            <serviceable>true</serviceable>     <!-- EGPWS_ENABLE -->
-            <configuration-module>
-                <category-1>                    <!-- AIRCRAFT_MODE_TYPE_SELECT -->
-                   255 <!-- aircraft type T1, fast turbofan -->
-                </category-1>
-                <category-4>                    <!-- ALTITUDE_CALLOUTS -->
-                    13 <!-- enable all altitude callouts -->
-                </category-4>
-                <category-8>                    <!-- RADIO_ALTITUDE_INPUT_SELECT -->
-                     2
-                </category-8>
-                <category-13>                   <!-- INPUT_OUTPUT_DISCRETE_TYPE_SELECT -->
-                     5 <!-- flashing warning lamp -->
-                </category-13>
-            </configuration-module>
-            <voice>
-                <file-prefix type="string">Sounds/mk-viii/</file-prefix>
-            </voice>
-            <inputs>                            <!-- Module I/O -->
-                <arinc429>
-                    <!-- provide fixed value for decision height -->
-                    <decision-height-ncd> false </decision-height-ncd>
-                    <decision-height> 250 </decision-height>
-                </arinc429>
-            </inputs>
-            <speaker>                           <!-- Speaker Configuration -->
-                <max-dist type="double"> 200.0 </max-dist>        <!-- Max. distance where speaker is heard -->
-                <reference-dist type="double"> 2 </reference-dist> <!-- Distance to pilot -->
-                <volume type="double"> 0.6 </volume>          <!-- Volume at reference distance -->
-            </speaker>
-        </mk-viii>
+		<!-- mk-viii is disabled: to enable for testing purposes, toggle the "serviceable" property -->
+		<mk-viii>  <!-- mk-viii configuration, see: http://wiki.flightgear.org/index.php/GPWS -->
+		    <serviceable type="bool">false</serviceable>     <!-- EGPWS_ENABLE -->
+		    <configuration-module>
+		        <category-1>                    <!-- AIRCRAFT_MODE_TYPE_SELECT -->
+		           255 <!-- aircraft type T1, fast turbofan -->
+		        </category-1>
+		        <category-4>                    <!-- ALTITUDE_CALLOUTS -->
+		            13 <!-- enable all altitude callouts -->
+		        </category-4>
+		        <category-8>                    <!-- RADIO_ALTITUDE_INPUT_SELECT -->
+		             2
+		        </category-8>
+		        <category-13>                   <!-- INPUT_OUTPUT_DISCRETE_TYPE_SELECT -->
+		             5 <!-- flashing warning lamp -->
+		        </category-13>
+		    </configuration-module>
+		    <voice>
+		        <file-prefix type="string">Sounds/mk-viii/</file-prefix>
+		    </voice>
+		    <inputs>                            <!-- Module I/O -->
+		        <arinc429>
+		            <!-- provide fixed value for decision height -->
+		            <decision-height-ncd> false </decision-height-ncd>
+		            <decision-height> 250 </decision-height>
+		        </arinc429>
+		    </inputs>
+		    <speaker>                           <!-- Speaker Configuration -->
+		        <max-dist type="double"> 200.0 </max-dist>        <!-- Max. distance where speaker is heard -->
+		        <reference-dist type="double"> 2 </reference-dist> <!-- Distance to pilot -->
+		        <volume type="double"> 0.6 </volume>          <!-- Volume at reference distance -->
+		    </speaker>
+		</mk-viii>
+		<!-- tcas is disabled: to enable for testing purposes, toggle the "serviceable" property -->
+		<tcas>                                    <!-- http://wiki.flightgear.org/index.php/TCAS -->
+		    <serviceable type="bool">false</serviceable>
+		                                          <!-- TCAS ENABLE -->
+		    <inputs>
+		        <mode type="int">3</mode>         <!-- 0=off, 1=standby, 2=TA-only, 3=auto(TA/RA) -->
+		    </inputs>
+		    <speaker>                             <!-- Speaker Configuration -->
+		        <max-dist> 2 </max-dist>          <!-- Max. distance where speaker is heard -->
+		        <reference-dist> 1 </reference-dist> <!-- Distance to pilot -->
+		        <volume> 1.0 </volume>            <!-- Volume at reference distance -->
+		    </speaker>
+		</tcas>
 	</instrumentation>
 
 	<gear>