Date: 201207
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Aircraft component: Nosewheel Steering
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
Detector: Person Flight Crew
When detected: Other Takeoff roll
Result: Flight Crew Rejected Takeoff; Flight Crew Returned To Gate; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: During preflight; taxi; and beginning of takeoff roll everything seemed to be operating normally. Upon applying power to 40 percent for takeoff all indications were normal. Aircraft veered slightly right so I applied left rudder to compensate and continued to add takeoff thrust. Aircraft continued to veer to the right. I applied continuous left rudder to compensate. Once I reached full rudder deflection (approximately 40 KTS); I aborted takeoff. I brought the aircraft to a stop and determined steering via tiller was operational and returned to gate. Once back in the gate Maintenance Control advised me that the Mechanic was on another aircraft so the delay would be unknown. We decided deplaning passengers would be the best option until we received further information.While deplaning a Passenger got very verbally abusive and threatening to myself and a flight attendant. Once all passengers were deplaned I informed the gate that the Passenger in question would not be continuing on our flight. He (Gate Agent) agreed and Gate Agent was enlisted to defuse the situation. Meanwhile the Mechanic was able to complete rudder inspection and determined there were no issues with rudder. The aircraft was signed off 'ops check good' and we were instructed to re board. Although the Mechanic had reservations and did not think the rudder was the root problem; Maintenance Control directed him to sign it off. So he did. While boarding Gate Agent notified me that the Passenger I had denied boarding was asking to apologize in hopes of being permitted to continue on this flight. As I was making my way to the gate this Passenger began to threaten and verbally abuse Gate Agent. At this point she (Passenger) was not permitted to speak with me and law enforcement was called. Law enforcement removed her from the gate. We continued to pushback. The ramp crew reengaged steering on ground service panel and departed. As I called for rudder check I noticed 'steer off' was no longer illuminated on the EICAS as it was prior to push. I then hit my steering disconnect switch and heard a grinding noise and felt vibration in the switch. I then asked the First Officer to try his steering disconnect switch. His did the same thing. We again returned to gate. Maintenance Control was again notified and Mechanic sent out. After much troubleshooting the steering was still inoperative and sporadic. It was finally determined that the microswitch in the tiller was inoperative and therefore steering did not disengage when tiller released for takeoff. Therefore we encountered a steering runaway situation on the takeoff roll with neither disconnect switch operational. Flight was subsequently cancelled and we were advised of a show time the next afternoon. More thorough inspection of problem by Maintenance on initial return to gate would have prevented the second return.




Synopsis: EMB170 crew experienced difficulty steering during the initial portion of the takeoff roll; subsequently rejecting the takeoff. Maintenance found no issues with the rudder and the log is signed off. After the next pushback and engine start it is determined that the nose wheel steering disconnect is not functioning properly and the flight is eventually canceled.