Accident Summary
An aircraft flying from Huai'an-Lianshui Airport to Shanghai-Hongqiao Airport experienced an uneventful flight before initiating an approach in marginal weather conditions with light rain showers. After touchdown on runway 18L, the crew began the braking procedure when the aircraft deviated to the left and veered off the runway. Contacting soft ground, the nose gear collapsed, and the aircraft slid for several dozen meters before coming to rest. All 49 occupants evacuated safely. The aircraft sustained damage beyond repair.
Investigation Findings
The official investigation determined that the runway excursion resulted from foreign object debris inside the electrohydraulic servo valve (EHSV). The debris blocked a hydraulic port, causing an uncommanded nose wheel deflection to the left. Prior to the disassembly of the EHSV and discovery of the debris, the unit had passed an acceptance test as performed on any newly manufactured unit.
Safety Recommendations
The National Transportation Safety Board (NTSB) reported that a number of pilots use binder brackets instead of the chart holders installed by Embraer to hold their binders (containing charts). These binder brackets have not been approved by Embraer. The binder is located directly above the nosewheel steering tiller. The NTSB expressed concern that a binder held by an unapproved bracket may become dislodged, fall, and strike the tiller, engaging the nosewheel steering system and possibly providing a nosewheel steering input. If this happens during the landing roll, the input could cause a runway excursion. The NTSB recommended studying and revising the acceptance tests and issuing an operational bulletin to inform flight crews that the use of binder brackets is not approved and could create a hazardous situation if the binder becomes dislodged.