Narrative:

During taxi out to runway 01 at sfo both first officer and I got a brief smell of a strange odor we could not identify. It dissipated rapidly and there was no smell by the time we neared #1 position. I concluded it must have been something the engine or air conditioning system, from outside the aircraft, in the air, had picked up. There were no abnormal engine or system indications in the cockpit. Takeoff and climb were normal and no additional odor was smelled till just before level off at 37000 when the same odor was smelled in the cockpit and this time much stronger. I accomplished the emergency procedures for smoke and fumes in the cockpit, but there was no smoke and I'm not sure the odor could be called fumes. There still was no indication that anything was wrong with the aircraft. Shortly thereafter the flight attendants complained about the smell in the cabin and said the passengers were beginning to complain. I waited several mins to see if there was any change after going through the emergency procedures. There was no improvement. I decided to divert to las where an uneventful landing was made. An FAA maintenance inspector along with the fire chief boarded the aircraft as soon as it reached the gate and also smelled the strong odor. The proper logbook entries were made, dispatch cancelled the flight. Maintenance inspected the aircraft for over 5 hours, but could not find anything that caused the smell. The next morning I ferried the aircraft to pittsburgh for further inspection. There was no odor on this flight and the aircraft performed perfectly. At this time there is still no explanation as to the cause of this odor though it was strong enough to cause a raspy throat and I personally got a headache from it.

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Original NASA ASRS Text

Title: LGT AT CRUISE HAS UNUSUAL ODOR AND FUMES IN COCKPIT AND CABIN. DIVERTS TO LAND.

Narrative: DURING TAXI OUT TO RWY 01 AT SFO BOTH FO AND I GOT A BRIEF SMELL OF A STRANGE ODOR WE COULD NOT IDENT. IT DISSIPATED RAPIDLY AND THERE WAS NO SMELL BY THE TIME WE NEARED #1 POS. I CONCLUDED IT MUST HAVE BEEN SOMETHING THE ENG OR AIR CONDITIONING SYS, FROM OUTSIDE THE ACFT, IN THE AIR, HAD PICKED UP. THERE WERE NO ABNORMAL ENG OR SYS INDICATIONS IN THE COCKPIT. TKOF AND CLB WERE NORMAL AND NO ADDITIONAL ODOR WAS SMELLED TILL JUST BEFORE LEVEL OFF AT 37000 WHEN THE SAME ODOR WAS SMELLED IN THE COCKPIT AND THIS TIME MUCH STRONGER. I ACCOMPLISHED THE EMER PROCS FOR SMOKE AND FUMES IN THE COCKPIT, BUT THERE WAS NO SMOKE AND I'M NOT SURE THE ODOR COULD BE CALLED FUMES. THERE STILL WAS NO INDICATION THAT ANYTHING WAS WRONG WITH THE ACFT. SHORTLY THEREAFTER THE FLT ATTENDANTS COMPLAINED ABOUT THE SMELL IN THE CABIN AND SAID THE PAXS WERE BEGINNING TO COMPLAIN. I WAITED SEVERAL MINS TO SEE IF THERE WAS ANY CHANGE AFTER GOING THROUGH THE EMER PROCS. THERE WAS NO IMPROVEMENT. I DECIDED TO DIVERT TO LAS WHERE AN UNEVENTFUL LNDG WAS MADE. AN FAA MAINT INSPECTOR ALONG WITH THE FIRE CHIEF BOARDED THE ACFT AS SOON AS IT REACHED THE GATE AND ALSO SMELLED THE STRONG ODOR. THE PROPER LOGBOOK ENTRIES WERE MADE, DISPATCH CANCELLED THE FLT. MAINT INSPECTED THE ACFT FOR OVER 5 HRS, BUT COULD NOT FIND ANYTHING THAT CAUSED THE SMELL. THE NEXT MORNING I FERRIED THE ACFT TO PITTSBURGH FOR FURTHER INSPECTION. THERE WAS NO ODOR ON THIS FLT AND THE ACFT PERFORMED PERFECTLY. AT THIS TIME THERE IS STILL NO EXPLANATION AS TO THE CAUSE OF THIS ODOR THOUGH IT WAS STRONG ENOUGH TO CAUSE A RASPY THROAT AND I PERSONALLY GOT A HEADACHE FROM IT.

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.