Atx small transport cargo jet suffers critical windshield failure.

Attributes
ACN	151527
Time
Date	199007
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ict
State Reference	KS
Altitude	msl bound lower : 41000 msl bound upper : 41000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 350 flight time total : 5800 flight time type : 1000
ASRS Report	151527
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : exited adverse environment flight crew : overcame equipment problem other
Consequence	other
Supplementary
Primary Problem	Aircraft

Narrative:

While in cruise at fl 410 in small transport there was a sound of a gun discharging, cabin began to climb, small air rushing sound both inner/outer pilots windshield had split. We immediately made an emergency descent and landed wichita, ict, airport. At the time of occurrence, speed was .mach 78, windshield heat was off, pressurization, cabin altitude, about 8500', no fluctuations and no birds etc. At cruise for about 1 1/2 hours. Both panes split so quick it appeared to be simultaneous. No parts left the aircraft. Not knowing complete damage, began an emergency descent. We also allowed cabin altitude to climb to reduce cabin differential to reduce pressure on airframe. When able, we officially declared an emergency and landed uneventfully at wichita, ks. The defect went from the center post down under windshield head duct and disappeared out of sight. I estimate length to be over 12' from attach point to attach point. Both sections of windshield were broken similarly and displacement of panels occurred. Maintenance facility at ict advised first occurrence of dual pane failure. Aircraft time about 9800 hours and windshield appears to have been not original but not verified.

Original NASA ASRS Text

Title: ATX SMT CARGO JET SUFFERS CRITICAL WINDSHIELD FAILURE.

Narrative: WHILE IN CRUISE AT FL 410 IN SMT THERE WAS A SOUND OF A GUN DISCHARGING, CABIN BEGAN TO CLB, SMALL AIR RUSHING SOUND BOTH INNER/OUTER PLTS WINDSHIELD HAD SPLIT. WE IMMEDIATELY MADE AN EMER DSNT AND LANDED WICHITA, ICT, ARPT. AT THE TIME OF OCCURRENCE, SPD WAS .MACH 78, WINDSHIELD HEAT WAS OFF, PRESSURIZATION, CABIN ALT, ABOUT 8500', NO FLUCTUATIONS AND NO BIRDS ETC. AT CRUISE FOR ABOUT 1 1/2 HRS. BOTH PANES SPLIT SO QUICK IT APPEARED TO BE SIMULTANEOUS. NO PARTS LEFT THE ACFT. NOT KNOWING COMPLETE DAMAGE, BEGAN AN EMER DSNT. WE ALSO ALLOWED CABIN ALT TO CLB TO REDUCE CABIN DIFFERENTIAL TO REDUCE PRESSURE ON AIRFRAME. WHEN ABLE, WE OFFICIALLY DECLARED AN EMER AND LANDED UNEVENTFULLY AT WICHITA, KS. THE DEFECT WENT FROM THE CTR POST DOWN UNDER WINDSHIELD HEAD DUCT AND DISAPPEARED OUT OF SIGHT. I ESTIMATE LENGTH TO BE OVER 12' FROM ATTACH POINT TO ATTACH POINT. BOTH SECTIONS OF WINDSHIELD WERE BROKEN SIMILARLY AND DISPLACEMENT OF PANELS OCCURRED. MAINT FAC AT ICT ADVISED FIRST OCCURRENCE OF DUAL PANE FAILURE. ACFT TIME ABOUT 9800 HRS AND WINDSHIELD APPEARS TO HAVE BEEN NOT ORIGINAL BUT NOT VERIFIED.

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.