Narrative:

En route from psp to sfo, approaching the palmdale VOR at FL230 we noted smoke coming from the forward portion of the glare shield. I was the PF and the first officer was the PNF. While the first officer donned his oxygen mask and smoke goggles, I declared an emergency. I then donned my oxygen mask and smoke goggles. When declaring the emergency, I said, 'flight XXX, smoke in the cockpit, declaring an emergency, starting a descent.' I was told to stop at FL220 due to traffic. Regardless, I told ATC we needed to continue our descent. ATC insisted we stop our descent at FL220 due to traffic. In order not to create another emergency, I stopped at FL220. I then asked for the closest airport and was told palmdale was below us. My first officer immediately began searching for airport information in the commercial chart manuals and performance book. While my first officer was searching for information, I called the flight attendant and told her we had smoke in the cockpit and asked her if there was smoke in the cabin. The answer was no. I told her we were diverting to a nearby airport and to prepare the cabin for an evacuate/evacuation. At the same time I told her she would have ample time to prepare the cabin and that I would get back to her. My first officer was unable to locate any information on the palmdale airport. I then asked for airport information from ATC and none was given to me. Due to no airport information, I was forced to divert to another airport. I then asked for the distance to lax and was told 45 mi. Knowing there was fire equipment and having all the airport information aboard our aircraft, I decided it would be prudent for us to divert to lax. Also, I figured the time it would take us to descend from FL220 to the palmdale airport it would take us approximately the same amount of time to descend into lax. Regardless, we needed time to read and execute the emergency, abnormal, and normal checklist. ATC gave us direct vectors toward lax. Soon after receiving vectors, I told ATC to roll the fire trucks. I flew the aircraft and operated the radios while the first officer proceeded with the QRH procedures. He then continued with the descent and before landing checklist. On final approach, I called the flight attendant and told her we were landing and not to do anything until she heard from me. After clearing the runway, I immediately stopped on taxiway east. I then called the flight attendant and asked her if there was smoke in the cabin. The answer was no. I told her to keep the passenger seated. I then moved the aircraft approximately 50 more ft into an open ramp area near the fire trucks. We proceeded with a shutdown checklist. After completing the checklist I opened the cockpit and cabin forward entry door. I told the passenger we had some smoke in the cockpit and to remain seated while a fireman checks out the cockpit. After no smoke was found, I had the passenger deplane onto the ramp in a secured area. Before deplaning, I told the passenger a bus would take them to the terminal and their bags would shortly follow. I also thanked them for their patience. While the passenger were deplaning, the first officer called lax operations. Soon after calling, a bus picked up the passenger. We grabbed our bags and the airport authority/authorized took us to operations. I then called the manager on duty. Soon after talking with the manager on duty, I talked with dispatch. I wrote up the problem in the aircraft and showed the maintenance supervisor where the smoke was coming from. According to the maintenance supervisor, the smoke was caused by the left windshield heat wire bundle under the glare shield. Due to the windshield heat turning on and off automatically during flight, this explains why the smoke continued to start and stop. The smoke stopped completely during our final descent into lax. This is explained by the first officer turning off the windshield heat descending through FL180 or thereabouts. We never received any warnings or indication of problems during this flight. The amount of smoke and visibility never got really bad in the cockpit. Since no smoke was observed after landing and since passenger safety was not at risk, I felt an evacuate/evacuation was unnecessary. An evacuate/evacuation would have only caused undue risk and possible injury to the passenger. My flight crew did an excellent job given the known circumstances they had to deal with.

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Original NASA ASRS Text

Title: E120 CREW EXPERIENCED SMOKE IN THE COCKPIT, DECLARED AN EMER AND LANDED.

Narrative: ENRTE FROM PSP TO SFO, APCHING THE PALMDALE VOR AT FL230 WE NOTED SMOKE COMING FROM THE FORWARD PORTION OF THE GLARE SHIELD. I WAS THE PF AND THE FO WAS THE PNF. WHILE THE FO DONNED HIS OXYGEN MASK AND SMOKE GOGGLES, I DECLARED AN EMER. I THEN DONNED MY OXYGEN MASK AND SMOKE GOGGLES. WHEN DECLARING THE EMER, I SAID, 'FLT XXX, SMOKE IN THE COCKPIT, DECLARING AN EMER, STARTING A DSCNT.' I WAS TOLD TO STOP AT FL220 DUE TO TFC. REGARDLESS, I TOLD ATC WE NEEDED TO CONTINUE OUR DSCNT. ATC INSISTED WE STOP OUR DSCNT AT FL220 DUE TO TFC. IN ORDER NOT TO CREATE ANOTHER EMER, I STOPPED AT FL220. I THEN ASKED FOR THE CLOSEST ARPT AND WAS TOLD PALMDALE WAS BELOW US. MY FO IMMEDIATELY BEGAN SEARCHING FOR ARPT INFO IN THE COMMERCIAL CHART MANUALS AND PERFORMANCE BOOK. WHILE MY FO WAS SEARCHING FOR INFO, I CALLED THE FLT ATTENDANT AND TOLD HER WE HAD SMOKE IN THE COCKPIT AND ASKED HER IF THERE WAS SMOKE IN THE CABIN. THE ANSWER WAS NO. I TOLD HER WE WERE DIVERTING TO A NEARBY ARPT AND TO PREPARE THE CABIN FOR AN EVAC. AT THE SAME TIME I TOLD HER SHE WOULD HAVE AMPLE TIME TO PREPARE THE CABIN AND THAT I WOULD GET BACK TO HER. MY FO WAS UNABLE TO LOCATE ANY INFO ON THE PALMDALE ARPT. I THEN ASKED FOR ARPT INFO FROM ATC AND NONE WAS GIVEN TO ME. DUE TO NO ARPT INFO, I WAS FORCED TO DIVERT TO ANOTHER ARPT. I THEN ASKED FOR THE DISTANCE TO LAX AND WAS TOLD 45 MI. KNOWING THERE WAS FIRE EQUIP AND HAVING ALL THE ARPT INFO ABOARD OUR ACFT, I DECIDED IT WOULD BE PRUDENT FOR US TO DIVERT TO LAX. ALSO, I FIGURED THE TIME IT WOULD TAKE US TO DSND FROM FL220 TO THE PALMDALE ARPT IT WOULD TAKE US APPROX THE SAME AMOUNT OF TIME TO DSND INTO LAX. REGARDLESS, WE NEEDED TIME TO READ AND EXECUTE THE EMER, ABNORMAL, AND NORMAL CHKLIST. ATC GAVE US DIRECT VECTORS TOWARD LAX. SOON AFTER RECEIVING VECTORS, I TOLD ATC TO ROLL THE FIRE TRUCKS. I FLEW THE ACFT AND OPERATED THE RADIOS WHILE THE FO PROCEEDED WITH THE QRH PROCS. HE THEN CONTINUED WITH THE DSCNT AND BEFORE LNDG CHKLIST. ON FINAL APCH, I CALLED THE FLT ATTENDANT AND TOLD HER WE WERE LNDG AND NOT TO DO ANYTHING UNTIL SHE HEARD FROM ME. AFTER CLRING THE RWY, I IMMEDIATELY STOPPED ON TXWY E. I THEN CALLED THE FLT ATTENDANT AND ASKED HER IF THERE WAS SMOKE IN THE CABIN. THE ANSWER WAS NO. I TOLD HER TO KEEP THE PAX SEATED. I THEN MOVED THE ACFT APPROX 50 MORE FT INTO AN OPEN RAMP AREA NEAR THE FIRE TRUCKS. WE PROCEEDED WITH A SHUTDOWN CHKLIST. AFTER COMPLETING THE CHKLIST I OPENED THE COCKPIT AND CABIN FORWARD ENTRY DOOR. I TOLD THE PAX WE HAD SOME SMOKE IN THE COCKPIT AND TO REMAIN SEATED WHILE A FIREMAN CHKS OUT THE COCKPIT. AFTER NO SMOKE WAS FOUND, I HAD THE PAX DEPLANE ONTO THE RAMP IN A SECURED AREA. BEFORE DEPLANING, I TOLD THE PAX A BUS WOULD TAKE THEM TO THE TERMINAL AND THEIR BAGS WOULD SHORTLY FOLLOW. I ALSO THANKED THEM FOR THEIR PATIENCE. WHILE THE PAX WERE DEPLANING, THE FO CALLED LAX OPS. SOON AFTER CALLING, A BUS PICKED UP THE PAX. WE GRABBED OUR BAGS AND THE ARPT AUTH TOOK US TO OPS. I THEN CALLED THE MGR ON DUTY. SOON AFTER TALKING WITH THE MGR ON DUTY, I TALKED WITH DISPATCH. I WROTE UP THE PROB IN THE ACFT AND SHOWED THE MAINT SUPVR WHERE THE SMOKE WAS COMING FROM. ACCORDING TO THE MAINT SUPVR, THE SMOKE WAS CAUSED BY THE L WINDSHIELD HEAT WIRE BUNDLE UNDER THE GLARE SHIELD. DUE TO THE WINDSHIELD HEAT TURNING ON AND OFF AUTOMATICALLY DURING FLT, THIS EXPLAINS WHY THE SMOKE CONTINUED TO START AND STOP. THE SMOKE STOPPED COMPLETELY DURING OUR FINAL DSCNT INTO LAX. THIS IS EXPLAINED BY THE FO TURNING OFF THE WINDSHIELD HEAT DSNDING THROUGH FL180 OR THEREABOUTS. WE NEVER RECEIVED ANY WARNINGS OR INDICATION OF PROBS DURING THIS FLT. THE AMOUNT OF SMOKE AND VISIBILITY NEVER GOT REALLY BAD IN THE COCKPIT. SINCE NO SMOKE WAS OBSERVED AFTER LNDG AND SINCE PAX SAFETY WAS NOT AT RISK, I FELT AN EVAC WAS UNNECESSARY. AN EVAC WOULD HAVE ONLY CAUSED UNDUE RISK AND POSSIBLE INJURY TO THE PAX. MY FLC DID AN EXCELLENT JOB GIVEN THE KNOWN CIRCUMSTANCES THEY HAD TO DEAL WITH.

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.