B737-800
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport
Human Factors; Aircraft
Departed ZZZZ Runway XX. I was pilot flying and First Officer was pilot monitoring. On takeoff roll heard a loud noise from the right side of the cockpit. Looked over to see the First Officer's side window open. Glancing back at my airspeed we were now past 80 knots and I elected to continue the takeoff per the QRH. Very hard to communicate but managed to direct the First Officer to close the window. He struggled trying to do so and I realized that it was out of the track. I advised Tower through the noise that we had a problem and would need to return. The First Officer and I managed to complete the mechanical checklist via hand signals and gestures. We landed uneventfully on XY.  Maintenance later had to fly in a part for the window.
This B737 crew experienced an open First Officer cockpit window during takeoff above 80 knots. The Captain elected to continue the takeoff; and First Officer attempts to close the window were unsuccessful. Despite the difficulties with crew and ATC communications because of the loud wind noise a safe and uneventful return and landing were accomplished.