Narrative:

Flight dispatched APU inoperative. Accomplished normal checklists and APU inoperative checklist and started engines #1 and #3 at the gate, on time. Due to ramp congestion, remained at the gate for 7-10 mins with engines #1 and #3 running, packs on. Once off the gate, all routine until approximately abeam taxiway C. As we taxied on taxiway F, ms X, onboard leader, came to cockpit and reported a 'funny' odor in the rear of the aircraft. Now brought to our attention, we detected an 'exhaust like' faint smell in the cockpit as well. No visible smoke was ever present, smoke alarm silent. I had my so discuss this directly with the flight attendant over the interphone, then sent him back to assess the situation. My first officer felt strongly that the odor was exhaust pumps from a B767 close in front and perhaps some residual from sitting at the gate with engines running, or air start cart used for engines #1 and #3. At this same time, I ran engines #1 and #3 up to 1.2 EPR to enhance pack operation and cabin air flow. (Without an APU, significantly less airflow occurs with engines operating packs versus APU bleed.) so returned to the cockpit and advised that he detected no unusual odor and that ms X felt that although noticeable earlier, the odor appeared to have dissipated. The cockpit was free of odor now, as well. With engines #1 and #3 still up to 1.2 EPR, we used the xbleed checklist to start engine #2. At this time, the cockpit door was still open and all indications within the aircraft were normal. A normal takeoff was made. At approximately clean-up, a transient odor was noticed by me and immediately dissipated. At approximately 9500 ft on climb out, ms X returned to the cockpit and said that the odor had returned and that her eyes were burning. At that time, I elected to declare an emergency and return to atl. (We were at approximately 25 DME north of the field.) odor seemed to dissipate in the descent, and a normal approach and landing were accomplished. A normal approach and landing was made. We taxied to the gate. At the gate, I made a PA requesting passenger to take their personal belongings and exit the aircraft. One female passenger was extremely angry and engaging the onboard leader at the forward entry door as we awaited the jetway. Passenger were met by several customer service agents. I contacted flight control and the duty pilot to relay the situation and agree on the next course of action. One of the customer service agents suggested that we avoid the passenger, as some were angry. We said ok (as we left the jetway, some thanked us). We located a replacement aircraft. All, or nearly all, of our passenger boarded same and we flew an uneventful leg to alb. I spoke to mr Y in maintenance control later. He related that no problems with any system on ship were discovered, and it is back in service. Multiple inputs from crew on type and possible sources of odor in cabin. This was helpful and also complicated the analysis of our problem. Should have had more interaction with the passenger -- PA announcements -- prior to takeoff. After the fact, I wish I hadn't taken off although there was no concrete reason to not. Biggest lesson reinforced -- you can't say too much to passenger when there is, or there is perceived to be, a problem with the aircraft.

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Original NASA ASRS Text

Title: CAPT OF A B727-200 IS DISPATCHED WITH APU INOP. ENGS #1 AND #3 ARE STARTED AT THE GATE. AFTER TAXI OUT THERE ARE RPTS OF 'FUNNY' ODOR, EXHAUST TYPE FUMES. FO CHKS AND BELIEVES THAT IT COMES FROM THE LEADING ACFT IN THAT POS. AFTER TKOF, THE ODOR BECOMES STRONGER, ACFT RETURNS TO ARPT.

Narrative: FLT DISPATCHED APU INOP. ACCOMPLISHED NORMAL CHKLISTS AND APU INOP CHKLIST AND STARTED ENGS #1 AND #3 AT THE GATE, ON TIME. DUE TO RAMP CONGESTION, REMAINED AT THE GATE FOR 7-10 MINS WITH ENGS #1 AND #3 RUNNING, PACKS ON. ONCE OFF THE GATE, ALL ROUTINE UNTIL APPROX ABEAM TXWY C. AS WE TAXIED ON TXWY F, MS X, ONBOARD LEADER, CAME TO COCKPIT AND RPTED A 'FUNNY' ODOR IN THE REAR OF THE ACFT. NOW BROUGHT TO OUR ATTN, WE DETECTED AN 'EXHAUST LIKE' FAINT SMELL IN THE COCKPIT AS WELL. NO VISIBLE SMOKE WAS EVER PRESENT, SMOKE ALARM SILENT. I HAD MY SO DISCUSS THIS DIRECTLY WITH THE FLT ATTENDANT OVER THE INTERPHONE, THEN SENT HIM BACK TO ASSESS THE SIT. MY FO FELT STRONGLY THAT THE ODOR WAS EXHAUST PUMPS FROM A B767 CLOSE IN FRONT AND PERHAPS SOME RESIDUAL FROM SITTING AT THE GATE WITH ENGS RUNNING, OR AIR START CART USED FOR ENGS #1 AND #3. AT THIS SAME TIME, I RAN ENGS #1 AND #3 UP TO 1.2 EPR TO ENHANCE PACK OP AND CABIN AIR FLOW. (WITHOUT AN APU, SIGNIFICANTLY LESS AIRFLOW OCCURS WITH ENGS OPERATING PACKS VERSUS APU BLEED.) SO RETURNED TO THE COCKPIT AND ADVISED THAT HE DETECTED NO UNUSUAL ODOR AND THAT MS X FELT THAT ALTHOUGH NOTICEABLE EARLIER, THE ODOR APPEARED TO HAVE DISSIPATED. THE COCKPIT WAS FREE OF ODOR NOW, AS WELL. WITH ENGS #1 AND #3 STILL UP TO 1.2 EPR, WE USED THE XBLEED CHKLIST TO START ENG #2. AT THIS TIME, THE COCKPIT DOOR WAS STILL OPEN AND ALL INDICATIONS WITHIN THE ACFT WERE NORMAL. A NORMAL TKOF WAS MADE. AT APPROX CLEAN-UP, A TRANSIENT ODOR WAS NOTICED BY ME AND IMMEDIATELY DISSIPATED. AT APPROX 9500 FT ON CLBOUT, MS X RETURNED TO THE COCKPIT AND SAID THAT THE ODOR HAD RETURNED AND THAT HER EYES WERE BURNING. AT THAT TIME, I ELECTED TO DECLARE AN EMER AND RETURN TO ATL. (WE WERE AT APPROX 25 DME N OF THE FIELD.) ODOR SEEMED TO DISSIPATE IN THE DSCNT, AND A NORMAL APCH AND LNDG WERE ACCOMPLISHED. A NORMAL APCH AND LNDG WAS MADE. WE TAXIED TO THE GATE. AT THE GATE, I MADE A PA REQUESTING PAX TO TAKE THEIR PERSONAL BELONGINGS AND EXIT THE ACFT. ONE FEMALE PAX WAS EXTREMELY ANGRY AND ENGAGING THE ONBOARD LEADER AT THE FORWARD ENTRY DOOR AS WE AWAITED THE JETWAY. PAX WERE MET BY SEVERAL CUSTOMER SVC AGENTS. I CONTACTED FLT CTL AND THE DUTY PLT TO RELAY THE SIT AND AGREE ON THE NEXT COURSE OF ACTION. ONE OF THE CUSTOMER SVC AGENTS SUGGESTED THAT WE AVOID THE PAX, AS SOME WERE ANGRY. WE SAID OK (AS WE LEFT THE JETWAY, SOME THANKED US). WE LOCATED A REPLACEMENT ACFT. ALL, OR NEARLY ALL, OF OUR PAX BOARDED SAME AND WE FLEW AN UNEVENTFUL LEG TO ALB. I SPOKE TO MR Y IN MAINT CTL LATER. HE RELATED THAT NO PROBS WITH ANY SYS ON SHIP WERE DISCOVERED, AND IT IS BACK IN SVC. MULTIPLE INPUTS FROM CREW ON TYPE AND POSSIBLE SOURCES OF ODOR IN CABIN. THIS WAS HELPFUL AND ALSO COMPLICATED THE ANALYSIS OF OUR PROB. SHOULD HAVE HAD MORE INTERACTION WITH THE PAX -- PA ANNOUNCEMENTS -- PRIOR TO TKOF. AFTER THE FACT, I WISH I HADN'T TAKEN OFF ALTHOUGH THERE WAS NO CONCRETE REASON TO NOT. BIGGEST LESSON REINFORCED -- YOU CAN'T SAY TOO MUCH TO PAX WHEN THERE IS, OR THERE IS PERCEIVED TO BE, A PROB WITH THE ACFT.

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.