Airport Frankfurt Flughafen Terminal 3 wp quote: "Eine Anbindung an die Bahnstrecke Mannheim–Frankfurt am Main ist vorgesehen" i.e. A connection to rail line Mannheim / Frankfurt-am-Main is planned. This is south side, as new Terminal 3 jetways face Gateway Gardens train stop, so to speak, opposite side of the entire airfield, with new Terminal 3 west of Zeppelinheim across Autobahn 5 ( E 451 ) This is a big deal for the Riedbahn !
I understand the author would like to add a third line from Frankfurt, running south towards Mannheim.
In that case, I'd much much prefer the highspeed line to Cologne, which has a limit of 300 km/h. It'd also be the first time that line is represented in any simulator.