Narrative:

Level FL330, first officer observed a rapidly growing crack in his front outer windscreen. We requested descent and were cleared to FL250. During descent first officer's outer pane shattered. Due to the abrupt nature and severity of the shatter, and our uncertainty of its effect upon the inner pane, we requested descent to 10000 ft. ATC advised we would need to squawk 7700 for immediate descent. We did so. During descent we observed no traffic conflicts and were kept well informed and clear of traffic by ATC. ATC requested, if possible, we level at 13000 ft. We complied and at 13000 ft canceled emergency status, then diverted to cleveland. Callback conversation with reporter revealed the following information: the cracking windshield sounded like a shotgun being fired, when it happened. Windshield cracked into hundreds of pieces. Because radio frequency was congested the first officer was waiting to get in to request lower altitude. Controller stated lower was not available so the captain then declared an emergency and started descent. Maximum airspeed with a cracked windshield is 305 KTS IAS but captain kept airspeed much lower than that limit. Captain just wasn't certain of the strength of the windshield because the shattering was so dramatic. So he kept emergency status in effect until he was at a lower altitude, 13000 ft, and airspeed low, then he canceled the emergency. After ldng and the passenger were deplaning, many of the passenger noticed the shattered windshield because it was so noticeable. The windshield was replaced in about 5 hours and the same flight crew flew the aircraft the next day. The captain was not aware of this problem happening on any of their aircraft before or since this incident.

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Original NASA ASRS Text

Title: CRACKED WINDSHIELD INFLT.

Narrative: LEVEL FL330, FO OBSERVED A RAPIDLY GROWING CRACK IN HIS FRONT OUTER WINDSCREEN. WE REQUESTED DSCNT AND WERE CLRED TO FL250. DURING DSCNT FO'S OUTER PANE SHATTERED. DUE TO THE ABRUPT NATURE AND SEVERITY OF THE SHATTER, AND OUR UNCERTAINTY OF ITS EFFECT UPON THE INNER PANE, WE REQUESTED DSCNT TO 10000 FT. ATC ADVISED WE WOULD NEED TO SQUAWK 7700 FOR IMMEDIATE DSCNT. WE DID SO. DURING DSCNT WE OBSERVED NO TFC CONFLICTS AND WERE KEPT WELL INFORMED AND CLR OF TFC BY ATC. ATC REQUESTED, IF POSSIBLE, WE LEVEL AT 13000 FT. WE COMPLIED AND AT 13000 FT CANCELED EMER STATUS, THEN DIVERTED TO CLEVELAND. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CRACKING WINDSHIELD SOUNDED LIKE A SHOTGUN BEING FIRED, WHEN IT HAPPENED. WINDSHIELD CRACKED INTO HUNDREDS OF PIECES. BECAUSE RADIO FREQ WAS CONGESTED THE FO WAS WAITING TO GET IN TO REQUEST LOWER ALT. CTLR STATED LOWER WAS NOT AVAILABLE SO THE CAPT THEN DECLARED AN EMER AND STARTED DSCNT. MAX AIRSPD WITH A CRACKED WINDSHIELD IS 305 KTS IAS BUT CAPT KEPT AIRSPD MUCH LOWER THAN THAT LIMIT. CAPT JUST WASN'T CERTAIN OF THE STRENGTH OF THE WINDSHIELD BECAUSE THE SHATTERING WAS SO DRAMATIC. SO HE KEPT EMER STATUS IN EFFECT UNTIL HE WAS AT A LOWER ALT, 13000 FT, AND AIRSPD LOW, THEN HE CANCELED THE EMER. AFTER LDNG AND THE PAX WERE DEPLANING, MANY OF THE PAX NOTICED THE SHATTERED WINDSHIELD BECAUSE IT WAS SO NOTICEABLE. THE WINDSHIELD WAS REPLACED IN ABOUT 5 HRS AND THE SAME FLC FLEW THE ACFT THE NEXT DAY. THE CAPT WAS NOT AWARE OF THIS PROB HAPPENING ON ANY OF THEIR ACFT BEFORE OR SINCE THIS INCIDENT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.