Luxair flight LG8852, an Embraer ERJ-145LU, lost directional control after landing on runway 06 at Luxembourg-Findel Airport (LUX). The aircraft departed the runway to the right, and stopped by the airport perimeter fence. Causes The investigation has demonstrated that the veering off of the aircraft started with an uncommanded right turn, effectively being a hard over to the right of the nose gear. The fault was traced to the hydraulic manifold of the nose gear steering unit commanding the left or right turns either through the rudder pedals or the steering handwheel. It has been discovered that within this hydraulic manifold, o-ring seals started to disintegrate and these tiny bits of rubber being carried through the conduits of the manifold finally blocked one of the 2 orifices, (one for left turns and one for right turns) delivering the oil pressure imbalance to the steering cylinder. The resulting pressure differential across the steering cylinder drove the steering hard over. PARKER engineering confirmed that the C1 nozzle corresponds to the C1 of the manifold outlet, which corresponds to the left-turn cylinder. Therefore, if only the C2 can get pressure, then it would appear that only a right turn is possible. In fact, to produce a steering hard over, it is not sufficient to have one of the orifices blocked. The EMB 145 features a steering hard over protection, which cuts all hydraulic pressure to the Accident of Embraer manifold when a nose wheel deflection greater than 7 degrees is detected. This protection is disabled when the steering control handwheel is pressed. Thus, producing a hard over requires one of the two manifold orifices blocked and the steering tiller to be pressed.