Date: 201201
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Aircraft component: Cockpit Window
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: The First Officer was the pilot flying on takeoff. After 80 KTS and prior to rotation speed; the First Officer's window slid completely open. The Captain took control of the aircraft; and completed the rotation. Once safely airborne; the First Officer attempted to close the window; but it was mechanically impossible. The First Officer held the window mostly closed with arm strength so that interphone and radio communication were possible. When the Captain realized the window was not going to close; he requested to divert and was given heading and altitude assignments to facilitate a timely landing. The First Officer tuned all of the radios; reset the FMC for the landing airport; and ensured all checklist items were complete and resumed ATC communication while the Captain flew the aircraft. While on final approach the window fell completely out of the track and onto the First Officer. The First Officer simply placed the window on his armrest and continued the call outs throughout the landing sequence. Once safely on the ground and clear of both active runways; the Captain made a PA explaining what had happened and the reason for diverting. There was not enough time to communicate with flight attendants and passengers. Frankly; it was so loud in the cockpit that it may not have been practical and would likely have caused more alarm than was necessary. Maintenance met the aircraft at the gate; inspected the track; replaced the window; and cleared the logbook. One of the Maintenance Technicians pointed out that the locking pin on the faulty window was not working correctly.


Second narrative: The First Officer was the pilot flying as we started the takeoff. Between 80 KTS and Vr; the First Officer direct vision window came open and slid back. I took control of the aircraft and made the rotation and remained pilot flying for the remainder of the flight. The First Officer attempted to close the window as I made the turn to 210 degrees and continued the climb to 4;000 FT. ATC cleared us to a higher altitude and a turn northwest; but the First Officer was unable to close the window even after multiple attempts. I requested and was given clearance to remain at 4;000 FT. I retracted flaps and accelerated to 210 KTS; but the wind noise was getting too loud so I put the flaps back down and slowed the aircraft. I did not declare an emergency but told ATC that we had a window open and wanted to divert as quickly as possible. ATC gave us a climb to 5;000 FT and vectored us to the east; then south; until we called the airport in sight and they issued a visual approach. The First Officer held the window as much closed as he could for the entire flight to keep the noise level down as much as possible. At some point before landing; I noticed that part of the window was out of its sliding track. The landing was uneventful.This was our second flight in this aircraft and the First Officer stated that he had not opened the window on the ground and had in fact checked the window to verify that it was closed before takeoff. The biggest issue of this event was communication. The First Officer and I could not communicate without the use of the intercom system. Until the First Officer realized to keep his hot MIC out of the wind as much as possible; I had a few brief moments that made communication with ATC difficult. If that situation had gotten worse; I would have declared an emergency.


Synopsis: B737 flight crew reports the First Officer's sliding window coming open during takeoff with the First Officer as the flying pilot. The Captain assumes control and continues the takeoff while the First Officer attempts without success to close the window. The crew diverts to a suitable airport with ATC assistance and lands safely.