Newsmagazine reports, that the autopilot pushed the helicopter nose down and went offline.
The crew had no chance to regain control before overstress caused blades to disintegrate.
The autopilot was wrong programmed, not knowing wether it was Airbus or the Bundeswehr, who set up the Autopilot.
The fault wasn´t found in other tiger helicopters but restrictions have been implemented to prevent further accidents
Articel in German:
"Tiger"-Hubschrauber: Falsch eingestellter Auto-Pilot leitete Sturzflug ein - SPIEGEL ONLINE