Schallert finished 5th in the FIS Ski-Flying World Championships 1983 had his best individual career finish of 2nd in the normal hill in Strbske Pleso in 1985.
In 1983, Schallert placed fifth in the FIS Ski-Flying World Championships. His most successful performance was a second-place finish on the normal hill during the 1985 competition in Strbske Pleso.