Glf-4 crew reported that the right forward outer windshield shattered in ZOA pacific operation.

Attributes
ACN	558581
Time
Date	200208
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : koa.airport
State Reference	HI
Altitude	msl single value : 41000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa.artcc
Operator	general aviation : corporate
Make Model Name	Gulfstream IV
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : pacific enroute other
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 10000 flight time type : 1000
ASRS Report	558581
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : instrument pilot : multi engine
Experience	flight time total : 6700 flight time type : 600
ASRS Report	558200
Events
Anomaly	aircraft equipment problem : critical other anomaly other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance controller : provided flight assist flight crew : landed in emergency condition flight crew : declared emergency flight crew : diverted to another airport none taken : detected after the fact other
Consequence	other other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

While en route from hko-crq via R577 of the hawaiian track routing system, the aircraft I was PIC of experienced a shattered forward windshield outer pane on the right side. An emergency was declared via relay to comrdo and a descent and right turn off airway was begun. The flight returned to hko at FL290. Periodic position/status reports were given to comrdo, satcom, and through air carrier Y relay. Flight landed safely at hko 4 hours 10 mins after departure. Approximately 2 hours after takeoff from hko was when the emergency was declared. Supplemental information from acn 558200: I was first officer, PNF, in right seat. I smelled a faint odor of electrical smoke, and after 20-30 seconds the right forward windscreen outer layer shattered. We declared an emergency to ZOA via an air carrier Y flight in our vicinity, through comrdo. We descended to FL290, made a 180 degree turn, offsetting 25 NM from our oceanic track, then proceeded direct to kona. We advised ATC of our actions. We continued uneventfully to kona, using several other airliners to relay messages to ATC since our HF radio reception was poor. These relays were extremely helpful, allowing us to concentrate on our situation rather than struggling to understand scratchy HF radio xmissions. Landing in kona was uneventful. Maintenance later found the windshield heat temperature controller had failed, causing the window to overheat and fail.

Original NASA ASRS Text

Title: GLF-4 CREW RPTED THAT THE R FORWARD OUTER WINDSHIELD SHATTERED IN ZOA PACIFIC OP.

Narrative: WHILE ENRTE FROM HKO-CRQ VIA R577 OF THE HAWAIIAN TRACK ROUTING SYS, THE ACFT I WAS PIC OF EXPERIENCED A SHATTERED FORWARD WINDSHIELD OUTER PANE ON THE R SIDE. AN EMER WAS DECLARED VIA RELAY TO COMRDO AND A DSCNT AND R TURN OFF AIRWAY WAS BEGUN. THE FLT RETURNED TO HKO AT FL290. PERIODIC POS/STATUS RPTS WERE GIVEN TO COMRDO, SATCOM, AND THROUGH ACR Y RELAY. FLT LANDED SAFELY AT HKO 4 HRS 10 MINS AFTER DEP. APPROX 2 HRS AFTER TKOF FROM HKO WAS WHEN THE EMER WAS DECLARED. SUPPLEMENTAL INFO FROM ACN 558200: I WAS FO, PNF, IN R SEAT. I SMELLED A FAINT ODOR OF ELECTRICAL SMOKE, AND AFTER 20-30 SECONDS THE R FORWARD WINDSCREEN OUTER LAYER SHATTERED. WE DECLARED AN EMER TO ZOA VIA AN ACR Y FLT IN OUR VICINITY, THROUGH COMRDO. WE DSNDED TO FL290, MADE A 180 DEG TURN, OFFSETTING 25 NM FROM OUR OCEANIC TRACK, THEN PROCEEDED DIRECT TO KONA. WE ADVISED ATC OF OUR ACTIONS. WE CONTINUED UNEVENTFULLY TO KONA, USING SEVERAL OTHER AIRLINERS TO RELAY MESSAGES TO ATC SINCE OUR HF RADIO RECEPTION WAS POOR. THESE RELAYS WERE EXTREMELY HELPFUL, ALLOWING US TO CONCENTRATE ON OUR SIT RATHER THAN STRUGGLING TO UNDERSTAND SCRATCHY HF RADIO XMISSIONS. LNDG IN KONA WAS UNEVENTFUL. MAINT LATER FOUND THE WINDSHIELD HEAT TEMP CONTROLLER HAD FAILED, CAUSING THE WINDOW TO OVERHEAT AND FAIL.

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.