BE40 CREW HAD CRACKED COCKPIT WINDSHIELD.

Narrative

ON MAY/XA/01; BEECHJET DEPARTED COLUMBUS; OH (OSU) ON AN IFR FLT TO MADISON; WI. THE FLT DEPARTED AT APPROX XA20 PM LCL TIME WITH 7 PAX AND A CREW OF 2 PLTS. DEPARTING OSU; WE CLBED THROUGH MULTIPLE LAYERS OF CLOUDS ENRTE TO OUR CRUISING ALT OF FL310. AT FL310 THE WX CONDITIONS WERE VMC; AND THE AIR WAS FREE OF TURB. AFTER APPROX 40 MINS AT FL310 WE APCHED OUR INITIAL DSCNT POINT OF APPROX 80 MI SW OF MADISON; WI. WE THEN REQUESTED A LOWER ALT FROM ATC; AND WERE ISSUED A DSCNT CLRNC. THE WX AND FLT CONDITIONS IN THE DSCNT WERE MIXED VMC/IMC AND NEGATIVE TURB. DSNDING THROUGH FL180; WE HEARD A LOUD SNAP AND OBSERVED THAT THE L WINDSHIELD HAD SHATTERED. THE FRACTURE CTRED AROUND A CENTRAL IMPACT POINT APPROX 3 INCHES ABOVE THE LOWER WINDSHIELD FRAME AND 12 INCHES L OF THE VERT FRAME. THE FRACTURES RADIATED ABOVE; BELOW; AND TO THE SIDE OF THAT POINT. OUR INITIAL THOUGHT IS THAT WE HAD IMPACTED SOME FORM OF AIRBORNE DEBRIS. WE LEVELED AT 14000 FT IN IMC CONDITIONS WITH AN OUTSIDE AIR TEMP OF +8 DEGS C. WE QUICKLY ASCERTAINED THAT ONLY THE OUTER PLY OF THE WINDSHIELD HAD SHATTERED; THUS NOT REQUIRING AN IMMEDIATE EMER LNDG AT THE NEAREST SUITABLE ARPT. WE NOTIFIED ATC THAT WE HAD A CRACKED WINDSHIELD AND ASKED TO BE REROUTED TO GENERAL MITCHELL FIELD IN MILWAUKEE; WI; WHERE REPAIRS COULD BE ACCOMPLISHED. AT THIS POINT IN THE FLT; MKE WAS ACTUALLY CLOSER THAN OUR DEST ARPT OF MSN. WE COMPLETED AN INST APCH PROC AT MKE (ILS RWY 19R) AND LANDED WITHOUT INCIDENT.