Accident Description
While cruising at an altitude of 20,000 feet over Bavaria, a four-engine aircraft disappeared from radar screens at 2009LT. The aircraft subsequently crashed in a field near Forchheim, north of Nuremberg. The crew was unable to send any distress call prior to the impact. The airplane disintegrated on impact, and all 52 occupants were killed.
Probable Cause
The official investigation findings state that the accident probably occurred in one of two ways, though other causes could not be ruled out. The first possibility is a forced descent causing the aircraft to exceed structural stress limits during the approach maneuver or pull-out, due to: (1) a defect in an artificial horizon or an electric instrument of equal importance leading to an uncontrollable flight position; (2) unnoticed over-control of the electrical rudder or aileron trim adjustment while the autopilot was operating, with resulting flight movements after autopilot disconnection (the autopilot lacked a trim servo-indicator for excessive trim warnings); or (3) physical incapacity of one or both pilots. The second possibility is an intentional descent due to smoke, fire, or a similar emergency, during which structural stress limits were exceeded in the approach maneuver or pull-out.