fgdata/Aircraft/c172p/Tutorials/altimeter.xml

<PropertyList>
  <name>Setting the Altimeter</name>
  <description>
    The Altimeter on an aircraft works using air pressure. This varies due to weather conditions, so the altimeter must be set regularly to a known value.
    
Having the correct altimeter setting is important. As well as helping pilots to avoid any high terrain, it means that aircraft can be separated by altitude and not hit each other. This is particular important in busy airspace.
    
The source of this altimeter setting varies. At high altitudes, a standard pressure is used. At lower levels, and area setting is used, and around airports, the current airport setting is used.
    
This tutorial will teach you how to set the altimeter based on the ATIS (Automatic Terminal Information Service) for Livermore Municipal airport.
  </description>
  <audio-dir>Aircraft/c172p/tutorial/radio</audio-dir>
  <timeofday>morning</timeofday>
  <presets>
    <airport-id>KLVK</airport-id>
    <on-ground>1</on-ground>
    <runway>12</runway>
    <altitude-ft>-9999</altitude-ft>
    <latitude-deg>37.6952</latitude-deg>
    <longitude-deg>-121.8167</longitude-deg>
    <heading-deg>175.0</heading-deg>
    <airspeed-kt>0</airspeed-kt>
    <glideslope-deg>0</glideslope-deg>
    <offset-azimuth-deg>0</offset-azimuth-deg>
    <offset-distance-nm>0</offset-distance-nm>
  </presets>
  
  <init>
    <set>
      <property>/controls/gear/brake-parking</property>
      <value>1</value>
    </set>
    <set>
      <property>/controls/flight/flaps</property>
      <value>0.0</value>
    </set>
    <set>
      <property>/controls/engines/engine/magnetos</property>
      <value>0</value>
    </set>
    <set>
      <property>/controls/engines/engine/throttle</property>
      <value>0.0</value>
    </set>
    <set>
      <property>/engines/engine/running</property>
      <value>false</value>
    </set>
    <set>
      <property>/instrumentation/adf/frequencies/selected-khz</property>
      <value>340</value>
    </set>
    <set>
      <property>/environment/weather-scenario</property>
      <value>Fair weather</value>
    </set>
    <set>
      <property>/controls/flight/elevator-trim</property>
      <value>0.17</value>
    </set>
    
    <set>
      <property>/instrumentation/comm[0]/frequencies/selected-mhz</property>
      <value>119.650</value>
    </set>
  </init>
  
  <step>
    <message>In this lesson, you'll learn how to set the altimeter to the Livermore ATIS. I've already
      set the radio to the correct frequency - 119.65 MHz</message>
  </step>
  
  <step>
    <message>Listen to the ATIS message. If you cannot hear it, check the Sound Configuration item in the File menu.</message>
  </step>
  
  <step>
    <message>The ATIS message said the altimeter setting was 29.97.
      We can set this using Equipment->Instrument Settings, or we can adjust
      the altimeter so that the altimeter matches the altitude of Livermore - 380ft.
    </message>
    
    <view>
      <heading-offset-deg>353.8</heading-offset-deg>
      <pitch-offset-deg>-17.3</pitch-offset-deg>
      <roll-offset-deg>0.0</roll-offset-deg>
      <x-offset-m>-0.2</x-offset-m>
      <y-offset-m>0.3</y-offset-m>
      <z-offset-m>0.4</z-offset-m>
      <field-of-view>15.1</field-of-view>
    </view>
  </step>
  
  <step>
    <message>To adjust the altimeter directly, use the knob on the bottom left. Click on the right
      to increase the altitude, and left to decrease. Use the left mouse button to make small adjustments, and
      the right button to make large adjustments.
    </message>
    
    <view>
      <heading-offset-deg>353.8</heading-offset-deg>
      <pitch-offset-deg>-17.3</pitch-offset-deg>
      <roll-offset-deg>0.0</roll-offset-deg>
      <x-offset-m>-0.2</x-offset-m>
      <y-offset-m>0.3</y-offset-m>
      <z-offset-m>0.4</z-offset-m>
      <field-of-view>15.1</field-of-view>
    </view>
    
    <marker>
      <x-m>-0.3525</x-m>
      <y-m>-0.1640</y-m>
      <z-m>0.0409</z-m>
      <scale>0.8756</scale>
    </marker>
  </step>
  
  <step>
    <message>Set the altimeter to 380 feet, or the pressure setting to 29.97 inHG.</message>
    <view>
      <heading-offset-deg>353.8</heading-offset-deg>
      <pitch-offset-deg>-17.3</pitch-offset-deg>
      <roll-offset-deg>0.0</roll-offset-deg>
      <x-offset-m>-0.2</x-offset-m>
      <y-offset-m>0.3</y-offset-m>
      <z-offset-m>0.4</z-offset-m>
      <field-of-view>15.1</field-of-view>
    </view>
    
    <marker>
      <x-m>-0.3525</x-m>
      <y-m>-0.1640</y-m>
      <z-m>0.0409</z-m>
      <scale>0.8756</scale>
    </marker>

    <error>
      <message>That's too low. Increase the altimeter setting or altitude.</message>
      <condition>
        <less-than>
          <property>/instrumentation/altimeter/setting-inhg</property>
          <value>29.96</value>
        </less-than>
      </condition>
    </error>

    <error>
      <message>That's too high. Decrease the altimeter setting or altitude.</message>
      <condition>
        <greater-than>
          <property>/instrumentation/altimeter/setting-inhg</property>
          <value>29.98</value>
        </greater-than>
      </condition>
    </error>
    
    
    <exit>
      <condition>
        <and>
          <greater-than>
            <property>/instrumentation/altimeter/setting-inhg</property>
            <value>29.96</value>
          </greater-than>
          <less-than>
            <property>/instrumentation/altimeter/setting-inhg</property>
            <value>29.98</value>
          </less-than>
        </and>
      </condition>
      
    </exit>
  </step>
  <end>
    <message>If you set the pressure setting directly, you can double-check you've set the correct
      value by checking the current altitude.</message>
  </end>
  
</PropertyList>