Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Critical; Deviation - Track / Heading All Types
Flight Crew Returned To Departure Airport
Aircraft
We were assigned a short repositioning flight. We ran all the checks for Taxi and T/O and everything checked ok. We were cleared for takeoff and when; at 80 knots; the Captain transferred the controls to me the aircraft pulled to the right a bit; which some of them do occasionally on control transfer; so I put more left rudder in and straightened the aircraft out. The aircraft was now back on centerline and felt normal again. On rotation the aircraft yawed to the right; as if weather vaning into the wind but there was no cross wind; so it took more left rudder to keep it going straight. I noticed it and so did the Captain so he took control to see if he could fix it. We climbed on course for a couple of minutes to try to fix it or see if it would correct itself and it did not. We then advised ATC that we needed to return to the airport and received vectors back for an overweight but uneventful landing on 02.
A BAE125-850XP flight crew experienced unexplained right yaw on takeoff and returned to their departure airport.