Narrative:

Climbing out of ewr, flight ewr-dfw, experienced acrid smell in cockpit. Nasal and eye irritation. Called F/a's and there was a faint smell in first class. Continued as smell and irritation dissipated. Level at FL280 things seemed normal and we decided to continue to dfw. Received clearance to climb FL350. Passing FL300 smell, irritation etc returned worse than before. Remembering two other incidents (many yrs ago), I decided to declare an emergency and we descended rapidly into iad (ATC provided excellent service). Maintenance checked aircraft and found nothing. Aircraft had #1 engine changed prior to flight over night at ewr. Possible duct contamination. I expect to follow history further. Supplemental information from acn 169922. Surge of acrid air into cockpit. Like electrical wires. Diverted to iad. Callback conversation with reporter revealed the following information. Flight took off from ewr. New engine had been installed and during climb there was an acrid smell in cabin and cockpit but only briefly. Flight crew at first thought it was electrical but later realized it was from one of the air conditioning packs. Flight continued.

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Original NASA ASRS Text

Title: ACRID SMELL IN CABIN AND COCKPIT BRIEFLY DURING CLIMB. FLT CONTINUED. SMELL RETURNED. FLT DIVERTED TO IAD.

Narrative: CLBING OUT OF EWR, FLT EWR-DFW, EXPERIENCED ACRID SMELL IN COCKPIT. NASAL AND EYE IRRITATION. CALLED F/A'S AND THERE WAS A FAINT SMELL IN FIRST CLASS. CONTINUED AS SMELL AND IRRITATION DISSIPATED. LEVEL AT FL280 THINGS SEEMED NORMAL AND WE DECIDED TO CONTINUE TO DFW. RECEIVED CLRNC TO CLB FL350. PASSING FL300 SMELL, IRRITATION ETC RETURNED WORSE THAN BEFORE. REMEMBERING TWO OTHER INCIDENTS (MANY YRS AGO), I DECIDED TO DECLARE AN EMER AND WE DSNDED RAPIDLY INTO IAD (ATC PROVIDED EXCELLENT SVC). MAINT CHKED ACFT AND FOUND NOTHING. ACFT HAD #1 ENG CHANGED PRIOR TO FLT OVER NIGHT AT EWR. POSSIBLE DUCT CONTAMINATION. I EXPECT TO FOLLOW HISTORY FURTHER. SUPPLEMENTAL INFO FROM ACN 169922. SURGE OF ACRID AIR INTO COCKPIT. LIKE ELECTRICAL WIRES. DIVERTED TO IAD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. FLT TOOK OFF FROM EWR. NEW ENG HAD BEEN INSTALLED AND DURING CLB THERE WAS AN ACRID SMELL IN CABIN AND COCKPIT BUT ONLY BRIEFLY. FLT CREW AT FIRST THOUGHT IT WAS ELECTRICAL BUT LATER REALIZED IT WAS FROM ONE OF THE AIR CONDITIONING PACKS. FLT CONTINUED.

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.