Jakobarnholtz wrote on Mar 2^nd, 2015 at 5:41pm:

Hi. I has tried to install the 707-300 v1.3 under win 8.1 and p3dv2.5 with migration Tool. It (allmost) Works, but I have no undercarriage, and a floating 707 do look a Little silly :) Any suggestion is most welcome

NOTE: I almost missed this topic because you posted it in the 707 Legendary (FS9). You should have posted it in this forum: 707 Captain - General

You might only need to add this:

  <Launch.Addon>
    <Name>Captain Sim 707 Sound</Name>
    <Disabled>False</Disabled>
    <Path>Captain_Sim\707\cs.sound.dll</Path>
  </Launch.Addon>

to the P3D DLL.XML file to make the landing gear visible.

With the migration tool, I have seen some people say that it needs to be run in Legacy Mode to make Captain Sim aircraft to work properly. :-/