Folder of the TF-51D airplane that allows you to hop into the backseat.
Instructions: Extract the contents of this folder into this directory: Drive:\Program Files\Eagle Dynamics\DCS type\Mods\aircraft\ .
Then you are done!
Update 27 January, 2018: Updates to the TF-51D.lua file so it is more compatible to multiplayer.
Update 2 February, 2018: The mod was adapted into the new 2.5 variant of DCS.