AN MD80 IN CRUISE AT FL310 DECLARED AN EMER AND DIVERTED DUE TO FO WINDSHIELD FAILURE.

Narrative

DURING CRUISE FLIGHT AT FL310; THE R1 WINDSHIELD; AT THE TOP R CORNER; STARTED TO TURN A DARK BROWN COLOR AND CRACK. WE ACCOMPLISHED THE WINDSHIELD/WINDOW FAILURE OR ANTI-ICE INOPERATIVE PROC. AFTER COMPLETING THE PROC; THE WINDSHIELD CONTINUED TO CRACK MORE AND MORE AT A VERY FAST RATE. AT THIS POINT; I THOUGHT THE STRUCTURAL INTEGRITY OF THE WINDSHIELD WAS GOING TO BECOME COMPROMISED. WE DECLARED AN EMER WITH ATC; DESCENDED TO 10;000 FT MSL COORDINATED WITH DISPATCH BRIEFED THE FLIGHT ATTENDANTS AND PAX OF OUR SITUATION AND PLAN TO LAND AT ZZZ INTL ARPT. WE LANDED AT XB26 LCL WITHOUT FURTHER INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FO'S WINDSHIELD UPPER R CORNER BEGAN TO TURN A DARK BROWN COLOR AND THEN STARTED TO CRACK IN A MAPLE LEAF SHAPE ABOUT THE SIZE OF YOUR HAND. THE RPTR SAID THE OUTER GLASS PANE OVER THIS MAPLE LEAF SHAPE DEPARTED THE ACFT AND THEN UPPER CORNER ARCING AND MORE CRACKING CONTINUED. THE RPTR STATED FROM THE UPPER R CORNER A BROWN SUBSTANCE WAS MELTING AND OOZING OVER THE R EYEBROW WINDOW. THE RPTR SAID THE FO WAS MOVED OUT OF THE R SEAT UNTIL A LOWER ALT WAS REACHED DUE TO WINDOW STRUCTURAL INTEGRITY. THE RPTR STATED FOR CERTAIN THE OUTER PANE FAILED. RPTR IS UNCERTAIN IF ANY INNER PANE FAILED. THE MELTING AND BROWN MATERIAL ON THE EYEBROW WINDOW WAS OF GREAT CONCERN.