B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Other / Unknown
Aircraft Equipment Problem Less Severe
Flight Crew Rejected Takeoff; Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
Just as the 100 knot call was made the aircraft swerved to the left.  Attempted to bring aircraft back to centerline using right rudder; but aircraft continued left.  Reject was announced and maneuver completed.  Rejected Takeoff (RTO) engaged and was released manually 3-4 seconds later.  Max speed 110.  Advised tower and we cleared the runway.  Advised flight attendants to remain seated.  After talking with station maintenance and Maintenance Control we taxied back to the gate.
We began a normal takeoff roll. Thrust was verified set on both engines. When I moved my scan to the airspeed indicator to make the 100 knot call; the airplane yawed left; the captain called an aborted takeoff and began the Rejected Takeoff (RTO) maneuver. The airplane accelerated for another moment and I estimate the airplane reached 105-110 knots. I made calls to the passengers to remain seated and informed ATC. No Airport Rescue and Fire Fighting (ARFF) assistance was requested. We ran the rejected checklist and then discussed whether inspection was needed. After maintenance coordination we returned to the gate. Several tests and checks were run on engines flight controls and brakes and yielded no result. We were asked to perform a high speed taxi test. We coordinated with the Duty Manager who advised we were not authorized to do this type of taxi test. The flight was canceled and crew sent to rest.
A B737 flight crew experiences a sudden yaw at 100 knots during takeoff. The takeoff is rejected. Maintenance can find no apparent reason for the swerve and the flight is canceled.