Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Less Severe; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control; Flight Crew Rejected Takeoff; General Maintenance Action
Aircraft
Captain and I were ready to do a [test flight] for Aircraft X that just came out of maintenance. During the taxi out; the airplane felt fine and the flight controls check was successfully done. We were cleared for takeoff a few minutes later on Runway XXR. The Captain aligned the airplane to the runway centerline and we confirmed runway heading. On the initial addition of power; from idle position to halfway up to TOGA; the airplane veered left as if the nose wheel was not aligned with the centerline. Captain reduced the thrust to idle; re-centered the nose to the centerline; and added power again to halfway up; around 75% N2. As the airspeed increased; the airplane veered to the right. As the Captain tried correcting with left rudder; the airplane veered more to the right this time.Captain reduced the thrust levers and called out rejecting at around 30 kt. We did the necessary call-outs and communicated to ATC that we were rejecting and will be exiting the runway on the next right available; which was Taxiway XX. ATC queried our intentions. After analyzing and developing a plan; including the input from the Maintenance Representative in ZZZ who was in our jumpseat; we decided that the airplane was unsafe to fly and that we needed to go back to the hangar after running the appropriate checklists and complying with all SOPs. The taxi to the hangar was without issue.Unfortunately for the flight crew; the only way we could have found that error was when we did on take off roll; since the steering using the tiller was correct. Maintenance could have found it earlier while doing the heavy maintenance checks; but I am not sure.
CRJ700 First Officer reported that a loss of directional control during the takeoff roll led to a rejected takeoff.