The Sky Line shuttle train will not be operating from April 28 (11 PM) until June 24 (5 AM), due to technical maintenance. Extensive replacement busses will be in place for transfers between Terminals 1 and 2, as well as between the long-distance (ICE) train station and Terminal 2, and in the transit area. Please follow the respective signs.
More details are available here.
General flight information is available on your airline’s website or by calling 01806-FRAINFO (01806-3724636 - flat landline rate of 0.20 euro cents per call; maximum charge of 0.60 euro cents per call from a mobile network within Germany) and at www.frankfurt-airport.com or via the FRA Airport app.