Dash 8¶

The free DHC-8 model had a few bugs: three times the fuel consumption, an instrument that doesn’t load, error messages in the log and an autopilot oscillating on final approach. The analysis is in the article Dash 8: Vier Fehler und eigene Lackierung (German).

Dash 8 in a custom livery

Installation¶

cd "$FG_BASIS/Aircraft"
curl -LO https://codemich.de/medien/dash8/DHC-8_original_FGAddon_2026-10-16.zip
unzip -q DHC-8_original_FGAddon_2026-10-16.zip && rm DHC-8_original_FGAddon_2026-10-16.zip
ls DHC-8/dhc-8-200-set.xml
cp -r DHC-8 DHC-8.original
curl -LO https://codemich.de/medien/dash8/dash8_patch.zip
unzip -o dash8_patch.zip -d DHC-8 && rm dash8_patch.zip

This is the state of the FGAddon development branch from 16 October 2026, GPL v2. The changes and reasons are in AENDERUNGEN_Claude.md in the patch (German).

"$FG_BASIS/werkzeuge/starten.sh" --aircraft=dhc-8-200 --airport=EDDE

The fixes in detail¶

Three times the fuel consumption¶

In Engines/PW123D.xml the efficiency table was commented out, so JSBSim took a default value of about 0.3. On top of that, the specific consumption was set too low.

<psfc unit="LBS/HR/HP">0.45</psfc>
<table name="CombustionEfficiency_N1" type="internal">
  <tableData>
    0.0    0.50
    20.0   0.80
    24.6   0.95
    50.0   0.98
    70.0   1.00
    110.0  1.00
  </tableData>
</table>

Instrument doesn’t load¶

FlightGear 2024.1 doesn’t know <use alias=…> in conditions. In EADI.xml it becomes:

<property alias="/params/display-property" />

Error messages in the log¶

id-802.nas read a node that no longer exists. The 1 creates it if it is missing:

ias: props.globals.getNode("/it-autoflight/input/kts", 1),

Oscillation on final approach¶

At the same bank angle a slow aircraft turns faster, so the gain drops below 140 kt:

if (Velocities.airspeedKt.getValue() < 140) {
    Gain.rollCmdKpCalc = Gain.hdgGain.getValue() * math.max(Velocities.airspeedKt.getValue(), 70) / 140;
}

Warning lights¶

The glowing surfaces sit behind the button in the model. A material animation makes the button itself light up:

<animation>
  <type>material</type>
  <object-name>master_warning</object-name>
  <condition>
    <property>instrumentation/crew-alerting/master-warning-light/state</property>
    <greater-than>
      <property>systems/electrical/outputs/advsy[0]</property>
      <value>10</value>
    </greater-than>
  </condition>
  <emission><red>1</red><green>0.05</green><blue>0.05</blue></emission>
</animation>

Tip for your own scripts¶

If you shut down an engine with the condition lever at FUEL OFF, the model immediately resets the feather setting propeller-feather. It must therefore be set repeatedly, or the aircraft yaws.