Narrative:

While at FL330, .80 mach, window L1 on captain's side cracked in numerous places. Cracks appeared to be limited to outer pane only. 1 crack may have been limited to middle pane. This deformation was spontaneous with a loud pop or snap sound. Immediately requested a 180 degree turn with houston ATC and descent to FL240 with speed reduction to 250 KIAS. Did not declare an emergency. Also, immediately removed window heat to L1, removed windshield vent air, put on shoulder harnesses and donned goggles as a precaution. Reviewed procedures in operations manual for cracked windshield continued descent to 16000 ft and 250 KIAS and reduced cabin differential pressure to aid in minimizing affect.

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Original NASA ASRS Text

Title: A B727-200 IN CRUISE AT FL330 DIVERTED DUE TO CAPT'S L COCKPIT SLIDING WINDOW CRACKED WITH DEFORMATION.

Narrative: WHILE AT FL330, .80 MACH, WINDOW L1 ON CAPT'S SIDE CRACKED IN NUMEROUS PLACES. CRACKS APPEARED TO BE LIMITED TO OUTER PANE ONLY. 1 CRACK MAY HAVE BEEN LIMITED TO MIDDLE PANE. THIS DEFORMATION WAS SPONTANEOUS WITH A LOUD POP OR SNAP SOUND. IMMEDIATELY REQUESTED A 180 DEG TURN WITH HOUSTON ATC AND DSCNT TO FL240 WITH SPD REDUCTION TO 250 KIAS. DID NOT DECLARE AN EMER. ALSO, IMMEDIATELY REMOVED WINDOW HEAT TO L1, REMOVED WINDSHIELD VENT AIR, PUT ON SHOULDER HARNESSES AND DONNED GOGGLES AS A PRECAUTION. REVIEWED PROCS IN OPS MANUAL FOR CRACKED WINDSHIELD CONTINUED DSCNT TO 16000 FT AND 250 KIAS AND REDUCED CABIN DIFFERENTIAL PRESSURE TO AID IN MINIMIZING AFFECT.

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.