add mesh and other stuff to example aircraft

Hi
how to add a gltf model, later also other files etc. to an aircraft. In the example I've added a second mesh but doesn't build. Below the modified xml.
Many thanks

<LOD ModelFile="GaugeAircraft_LOD00.gltf" minSize="50"/>
<LOD ModelFile="GaugeAircraft_LOD01.gltf" minSize="20"/>
<LOD ModelFile="GaugeAircraft_LOD02.gltf" minSize="10"/>
<LOD ModelFile="GaugeAircraft_LOD03.gltf" minSize="5"/>
<LOD ModelFile="GaugeAircraft_LOD04.gltf" minSize="1"/>
<LOD ModelFile="2GaugeAircraft_LOD00.gltf" minSize="50"/>
<LOD ModelFile="2GaugeAircraft_LOD01.gltf" minSize="20"/>
<LOD ModelFile="2GaugeAircraft_LOD02.gltf" minSize="10"/>
<LOD ModelFile="2GaugeAircraft_LOD03.gltf" minSize="5"/>
<LOD ModelFile="2GaugeAircraft_LOD04.gltf" minSize="1"/>