Loss of thrust could also mean that some sensors of the power plant could have been affected by icing and thus given wrong input for power setting. There is no need for ice ingestion. Rolls Royce Tay is a rather old engine design without FADEC (=computer control). It is quite a long time ago I flew the Fokker 100 so I do not have any special memory of icing problems. I also congratulate for the happy outcome, also in respect of the low visibility close to ground. In snow it is very very difficult to judge altitude and attitude. Fortunately it happened in Munich and not around an airport closer to cities or to mountains.