Date: 201211
Local time of day: 0601-1200
Location: ZDC.ARTCC, VA
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZDC
ATC / advisory: Center ZDC
Aircraft component: Cockpit Window
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Departure Airport; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During the climb level at FL 230; there was a loud pop and the First Officer's forward windscreen shattered from the electrical lead to the heating element and spreading out in many directions throughout the windscreen. Upon examination; it appeared that the outer panel was primarily affected. While I don't believe that anything struck the airplane; however; the place from where the cracks emanated looked like a bullet impact and was located right where the electrical lead attached to the power source for the window heat. There was no loss of pressurization. While the load bearing panel of the windscreen appeared to be intact; Dispatch was contacted and the we expressed our concern that we felt the aircraft had become un-airworthy and we reached a unanimous consensus with Dispatch that a return to our departure airport would be the most prudent action. The QRH actually guides the crew to continue normal operations if no differential restrictions apply. I will tell you this went counter to some common sense perspectives both the First Officer and I discussed. To our reasoning; there was no question that once the aircraft was on the ground; it would be considered un-airworthy and the damage not covered by an MEL. Furthermore; it just went counter to common sense to climb from FL230 to FL390 staring at a cracked and broken windscreen even though; from an engineering point of view; that may have been possible. Furthermore; if we felt the aircraft was in any way un-airworthy; continuing for another hour to a destination made no sense since we were 15 minutes away from a major Maintenance and pilot base. I also had some concerns as to what had caused the explosive force that had cracked the windscreen and did not feel comfortable not understanding why it happened. We relayed our thoughts to our Dispatcher who concurred. With the three of us on the same page; we elected to be more cautious than the QRH and divert to the nearest suitable airport which was our departure airport. We returned uneventfully; entered the discrepancy into the logbook; spoke with Dispatch; and were transferred to another aircraft. The passengers were all transferred to the new jet and we flew the remainder of the schedule without incident.




Synopsis: When the outer pane of First Officer's windshield shattered as they were at FL230 on their way to FL390 the flight crew of a B737-700 elected to return to their departure airport for maintenance and a fresh jet.