fgdata/Aircraft/ufo/Models/ufo.xml

<?xml version="1.0"?>

<PropertyList>

 <path>ufo.ac</path>

 <animation>
  <type>select</type>
  <condition>
   <or>
    <equals>
     <property>/sim/flight-model</property>
     <value>ufo</value>
    </equals>
    <property>/sim/model/always-show-in-MP</property>
   </or>
  </condition>
 </animation>

 <animation>
  <type>blend</type>
  <object-name>body</object-name>
  <property>/velocities/airspeed-kt</property>
  <factor>0.00025</factor>
  <min>0.2</min>
  <max>0.7</max>
 </animation>

 <animation>
  <type>spin</type>
  <object-name>body</object-name>
  <object-name>green_navigation_lights</object-name>
  <object-name>red_navigation_lights</object-name>
  <object-name>propulsion_lights</object-name>
  <property>/velocities/airspeed-kt</property>
  <factor>0.004</factor>
  <center>
   <x-m>0</x-m>
   <y-m>0</y-m>
   <z-m>0</z-m>
  </center>
  <axis>
   <x>0</x>
   <y>0</y>
   <z>1</z>
  </axis>
 </animation>

</PropertyList>