Narrative:

Prior to reaching louiz on A699 airway (approximately 150 mi east of vero beach, fl) I (X) was instructed by ZMA to report louiz on HF frequency. At louiz contact was attempted on #1 HF radio and #2 HF radio with no success. I also was unable to receive on the designated frequency after numerous attempts to transmit, the smell of burning wires was noticed. Approximately 1 min later, a haze of smoke was observed between the captain and first officer's seat, HF radios were shut off. My first officer concurred with my suggestion, return for the mainland and declare an emergency, promptly. Once this was agreed upon, the VHF radio was selected, an emergency was declared on the last VHF frequency, when no reply was received the common VHF was selected and retried. Meanwhile course reversal was commenced for the mainland, descent was initiated from FL410 to FL400 due to possible conflict with traffic that might have been behind me. After a couple more attempts, contact was established with an air carrier Y. I asked him to relay to ZMA that I was returning for the nearest suitable airport, an emergency was declared 'smoke in the cockpit,' by this time reception with ZMA was established and a vector for freeport, bahamas was received. An uneventful landing was made in freeport. After landing the aircraft was grounded and written up.

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Original NASA ASRS Text

Title: ACR LJ36 DECLARES ENRTE EMER WITH SMOKE IN THE COCKPIT.

Narrative: PRIOR TO REACHING LOUIZ ON A699 AIRWAY (APPROX 150 MI E OF VERO BEACH, FL) I (X) WAS INSTRUCTED BY ZMA TO RPT LOUIZ ON HF FREQ. AT LOUIZ CONTACT WAS ATTEMPTED ON #1 HF RADIO AND #2 HF RADIO WITH NO SUCCESS. I ALSO WAS UNABLE TO RECEIVE ON THE DESIGNATED FREQ AFTER NUMEROUS ATTEMPTS TO XMIT, THE SMELL OF BURNING WIRES WAS NOTICED. APPROX 1 MIN LATER, A HAZE OF SMOKE WAS OBSERVED BTWN THE CAPT AND FO'S SEAT, HF RADIOS WERE SHUT OFF. MY FO CONCURRED WITH MY SUGGESTION, RETURN FOR THE MAINLAND AND DECLARE AN EMER, PROMPTLY. ONCE THIS WAS AGREED UPON, THE VHF RADIO WAS SELECTED, AN EMER WAS DECLARED ON THE LAST VHF FREQ, WHEN NO REPLY WAS RECEIVED THE COMMON VHF WAS SELECTED AND RETRIED. MEANWHILE COURSE REVERSAL WAS COMMENCED FOR THE MAINLAND, DSCNT WAS INITIATED FROM FL410 TO FL400 DUE TO POSSIBLE CONFLICT WITH TFC THAT MIGHT HAVE BEEN BEHIND ME. AFTER A COUPLE MORE ATTEMPTS, CONTACT WAS ESTABLISHED WITH AN ACR Y. I ASKED HIM TO RELAY TO ZMA THAT I WAS RETURNING FOR THE NEAREST SUITABLE ARPT, AN EMER WAS DECLARED 'SMOKE IN THE COCKPIT,' BY THIS TIME RECEPTION WITH ZMA WAS ESTABLISHED AND A VECTOR FOR FREEPORT, BAHAMAS WAS RECEIVED. AN UNEVENTFUL LNDG WAS MADE IN FREEPORT. AFTER LNDG THE ACFT WAS GROUNDED AND WRITTEN UP.

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.