Horrible CFIT crash - unexcuseable seen the circumstances.
Trier-Föhren is a plain VFR / VMC landingsite, no navaid - no nothing !!
Trier - Föhren lies in a valley with the surrounding hills topping field elevation by 600 - 1000 ft. Possible diversion a/d nearby are on top of these hills.
Weather was definately IMC at a bad state >> see Metar Spangdahlem airbase attached to the report in Aviation Safety Network.
Apparently at the time of the crash nearby Frankfurt-Hahn airport - just south of the Mosel valley had gone to VFR conditions.
Even if still at IMC Hahn has a 3800 m long RWY and cat III ILS on both ends.
Luxemburg obviously was down to IFR minima at the time of the crash, so no good diversion a/d.
Finally, EDDK - Cologne - was plain CAVOK the entire day !! So why no diversion into safety, followed by a 1:45 h car drive??