Narrative:

Departed kin as flight XXXX, first officer's leg. Normal departure with no abnormalities noted on preflight or with departure. Climbing out of FL300, flight crew smelled a strong odor coming from the rear of the aircraft. Initially the crew did not have trouble breathing or seeing. The flight attendant advised the odor was not coming from the galley and that passenger were complaining about the odor all over the cabin. As per the predep briefing, captain began abnormal procedures checklist to rectify the situation. With the captain's concurrence, I notified kingston that we were detecting an odor in the cockpit and would like clearance to return to kingston. Decision to return to kingston versus montego bay was made since neither flight crew member was familiar with the airport and planning to land would have required more time. Kingston acknowledged our emergency and gave immediate clearance to return to the field. We received priority handling as an emergency aircraft. The arrival and landing into kingston were normal. Aircraft was inspected by arff equipment and determined to be safe to taxi to the gate. Arff was not able to communicate with the aircraft and would recommend that this be changed for future emergencys. Passenger were deplaned via airstairs since no evidence of danger existed. After inspection by the mechanic, the flight returned to miami without further incident. No cause for the odor/fumes was found. Technician advised that it was possibly the #2 engine which had recently been replaced. Crew coordination and execution was excellent.

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Original NASA ASRS Text

Title: A B737 CREW, CLBING THROUGH FL300, EXPERIENCED AN UNIDENTIFIABLE ODOR THROUGHOUT THE ACFT, RETURNED TO MKJP.

Narrative: DEPARTED KIN AS FLT XXXX, FO'S LEG. NORMAL DEP WITH NO ABNORMALITIES NOTED ON PREFLT OR WITH DEP. CLBING OUT OF FL300, FLC SMELLED A STRONG ODOR COMING FROM THE REAR OF THE ACFT. INITIALLY THE CREW DID NOT HAVE TROUBLE BREATHING OR SEEING. THE FLT ATTENDANT ADVISED THE ODOR WAS NOT COMING FROM THE GALLEY AND THAT PAX WERE COMPLAINING ABOUT THE ODOR ALL OVER THE CABIN. AS PER THE PREDEP BRIEFING, CAPT BEGAN ABNORMAL PROCS CHKLIST TO RECTIFY THE SIT. WITH THE CAPT'S CONCURRENCE, I NOTIFIED KINGSTON THAT WE WERE DETECTING AN ODOR IN THE COCKPIT AND WOULD LIKE CLRNC TO RETURN TO KINGSTON. DECISION TO RETURN TO KINGSTON VERSUS MONTEGO BAY WAS MADE SINCE NEITHER FLC MEMBER WAS FAMILIAR WITH THE ARPT AND PLANNING TO LAND WOULD HAVE REQUIRED MORE TIME. KINGSTON ACKNOWLEDGED OUR EMER AND GAVE IMMEDIATE CLRNC TO RETURN TO THE FIELD. WE RECEIVED PRIORITY HANDLING AS AN EMER ACFT. THE ARR AND LNDG INTO KINGSTON WERE NORMAL. ACFT WAS INSPECTED BY ARFF EQUIP AND DETERMINED TO BE SAFE TO TAXI TO THE GATE. ARFF WAS NOT ABLE TO COMMUNICATE WITH THE ACFT AND WOULD RECOMMEND THAT THIS BE CHANGED FOR FUTURE EMERS. PAX WERE DEPLANED VIA AIRSTAIRS SINCE NO EVIDENCE OF DANGER EXISTED. AFTER INSPECTION BY THE MECH, THE FLT RETURNED TO MIAMI WITHOUT FURTHER INCIDENT. NO CAUSE FOR THE ODOR/FUMES WAS FOUND. TECHNICIAN ADVISED THAT IT WAS POSSIBLY THE #2 ENG WHICH HAD RECENTLY BEEN REPLACED. CREW COORD AND EXECUTION WAS EXCELLENT.

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.