B737-800
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action
Human Factors; Procedure; Aircraft
During takeoff roll; FO (First Officer) seat became unlatched horizontally; causing FO to slide aft. As pilot monitoring; I assumed control of the aircraft and steered us back to runway center line until FO was ready to assume control again. Seat not properly locked horizontally. Latching mechanism possibly in need of adjustment. Double-checking seat lock with a good 'shove' prior to departure. Also closer maintenance inspection of seat latches may be warranted.
Captain reported assuming control after First Officer's seat slid back and prevented him from reaching the flight controls.