Narrative:

Prior to departing zza on the evening of jun/tue/01, the crew had discussed and reviewed a recurring problem with B767-200. This problem involved the 'right air conditioning pack' automatically shutting down on takeoff and/or landing. One of the mechanics, with whom the problem was being discussed, had ridden the aircraft from ZZZ to zza on a previous flight earlier in the day, and had witnessed the problem. Maintenance had elected to defer the right air conditioning pack for the next flight back to ZZZ, even though the pack appeared to function normally in all other phases of flight. On arrival at the aircraft, the captain served the aircraft APU running, and both packs on and operating, even though the right pack was deferred. All system appeared normal, and there was no odor emanating from the air conditioning system with just the APU operating. The cockpit setup and preflight was normal. Just prior to engine start, the left pack was shut off to reduce the noise in the cockpit, and within about 10 seconds of the pack being selected to 'off,' the APU did an 'automatic shutdown.' ground power was then applied to the aircraft, and the APU restarted. Once restarted, only the left pack was used for air conditioning. Engine start during push was normal. Just after engine start, and prior to taxi, the crew noticed an odor coming from the air conditioning packs that smelled as though someone had sprayed a can of 'wd-40' on the air conditioning pack. The odor wasn't strong or obnoxious, nor was there any smoke in the cockpit. The crew had smelled this before on a previous flight in the same aircraft, and therefore wasn't concerned. Taxi was resumed, and the odor appeared to diminish. The right air conditioning pack was being used at the request of the mechanic on board as a troubleshooting procedure to see if he could determine what the problem with the automatic-shutdowns during takeoff and landing might be. Takeoff was normal, with no problem with the right pack shutting down. During climb, going through about 13000 ft to 15000 ft, the first officer mentioned that he thought that the odor was getting stronger, and that his eyes were beginning to burn. The mechanic noticed the increase oil smell, but said that he wasn't having any problem with his eyes. The same was true for the captain, no eye problem. Taking into consideration the prior problems with the right air conditioning pack, the captain then elected to shut off the right air conditioning pack, and this appeared to solve the problem. The odor diminished and the first officer's eyes stopped stinging. The crew elected to continue the flight with just the left air conditioning pack operating and observing the MEL restrs with operating with just 1 pack. The flight continued normally until descent into the approach area of ZZZ, when descending through about 15000 ft, the first officer again noted the oil odor increasing, this even though the right pack was still shut off. The mechanic and captain also noted the increase. At about 8000 ft, the odor was getting strong enough that the captain instructed the first officer and mechanic to go on oxygen as a precautionary measure, to preclude any possible problems, even though there was no smoke visible in the cockpit. The crew then notified TRACON of the situation, but did not declare an emergency. Oxygen was used all the way to landing. After landing, the oil odor seemed to decrease rapidly, with hardly any odor in the cockpit after shutdown. Maintenance and the chief pilot were briefed of the situation. Human performance considerations: one could say that the perceived innocence of the situation could have been an error in judgement. The condition of the air conditioning system, having been a recurring problem, caused the captain to assume that there wasn't any greater problem than just an anomaly with the right pack, and that to continue the flight was safe. After looking at the situation and observing the eventual result of the decision made to continue, this probably wasn't the right choice. There was more to the problem than either the crew or maintenance were aware of. The inaction of maintenance to correct the problem promptly also played a big part in contributing to the situation. They continually forced the aircraft back into service without properly diagnosing the problem, therefore, putting the crew and passenger at risk. The crew's performance and ability to properly assess the situation were diminished by the fact that there was really no concern of the problem with the air conditioning system by maintenance. This led to the crew making incorrect judgements with regards to the safety of the flight.

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Original NASA ASRS Text

Title: B767-200 CREW HAD OIL AND FUMES FROM BOTH PACKS.

Narrative: PRIOR TO DEPARTING ZZA ON THE EVENING OF JUN/TUE/01, THE CREW HAD DISCUSSED AND REVIEWED A RECURRING PROB WITH B767-200. THIS PROB INVOLVED THE 'R AIR CONDITIONING PACK' AUTOMATICALLY SHUTTING DOWN ON TKOF AND/OR LNDG. ONE OF THE MECHS, WITH WHOM THE PROB WAS BEING DISCUSSED, HAD RIDDEN THE ACFT FROM ZZZ TO ZZA ON A PREVIOUS FLT EARLIER IN THE DAY, AND HAD WITNESSED THE PROB. MAINT HAD ELECTED TO DEFER THE R AIR CONDITIONING PACK FOR THE NEXT FLT BACK TO ZZZ, EVEN THOUGH THE PACK APPEARED TO FUNCTION NORMALLY IN ALL OTHER PHASES OF FLT. ON ARR AT THE ACFT, THE CAPT SERVED THE ACFT APU RUNNING, AND BOTH PACKS ON AND OPERATING, EVEN THOUGH THE R PACK WAS DEFERRED. ALL SYS APPEARED NORMAL, AND THERE WAS NO ODOR EMANATING FROM THE AIR CONDITIONING SYS WITH JUST THE APU OPERATING. THE COCKPIT SETUP AND PREFLT WAS NORMAL. JUST PRIOR TO ENG START, THE L PACK WAS SHUT OFF TO REDUCE THE NOISE IN THE COCKPIT, AND WITHIN ABOUT 10 SECONDS OF THE PACK BEING SELECTED TO 'OFF,' THE APU DID AN 'AUTO SHUTDOWN.' GND PWR WAS THEN APPLIED TO THE ACFT, AND THE APU RESTARTED. ONCE RESTARTED, ONLY THE L PACK WAS USED FOR AIR CONDITIONING. ENG START DURING PUSH WAS NORMAL. JUST AFTER ENG START, AND PRIOR TO TAXI, THE CREW NOTICED AN ODOR COMING FROM THE AIR CONDITIONING PACKS THAT SMELLED AS THOUGH SOMEONE HAD SPRAYED A CAN OF 'WD-40' ON THE AIR CONDITIONING PACK. THE ODOR WASN'T STRONG OR OBNOXIOUS, NOR WAS THERE ANY SMOKE IN THE COCKPIT. THE CREW HAD SMELLED THIS BEFORE ON A PREVIOUS FLT IN THE SAME ACFT, AND THEREFORE WASN'T CONCERNED. TAXI WAS RESUMED, AND THE ODOR APPEARED TO DIMINISH. THE R AIR CONDITIONING PACK WAS BEING USED AT THE REQUEST OF THE MECH ON BOARD AS A TROUBLESHOOTING PROC TO SEE IF HE COULD DETERMINE WHAT THE PROB WITH THE AUTO-SHUTDOWNS DURING TKOF AND LNDG MIGHT BE. TKOF WAS NORMAL, WITH NO PROB WITH THE R PACK SHUTTING DOWN. DURING CLB, GOING THROUGH ABOUT 13000 FT TO 15000 FT, THE FO MENTIONED THAT HE THOUGHT THAT THE ODOR WAS GETTING STRONGER, AND THAT HIS EYES WERE BEGINNING TO BURN. THE MECH NOTICED THE INCREASE OIL SMELL, BUT SAID THAT HE WASN'T HAVING ANY PROB WITH HIS EYES. THE SAME WAS TRUE FOR THE CAPT, NO EYE PROB. TAKING INTO CONSIDERATION THE PRIOR PROBS WITH THE R AIR CONDITIONING PACK, THE CAPT THEN ELECTED TO SHUT OFF THE R AIR CONDITIONING PACK, AND THIS APPEARED TO SOLVE THE PROB. THE ODOR DIMINISHED AND THE FO'S EYES STOPPED STINGING. THE CREW ELECTED TO CONTINUE THE FLT WITH JUST THE L AIR CONDITIONING PACK OPERATING AND OBSERVING THE MEL RESTRS WITH OPERATING WITH JUST 1 PACK. THE FLT CONTINUED NORMALLY UNTIL DSCNT INTO THE APCH AREA OF ZZZ, WHEN DSNDING THROUGH ABOUT 15000 FT, THE FO AGAIN NOTED THE OIL ODOR INCREASING, THIS EVEN THOUGH THE R PACK WAS STILL SHUT OFF. THE MECH AND CAPT ALSO NOTED THE INCREASE. AT ABOUT 8000 FT, THE ODOR WAS GETTING STRONG ENOUGH THAT THE CAPT INSTRUCTED THE FO AND MECH TO GO ON OXYGEN AS A PRECAUTIONARY MEASURE, TO PRECLUDE ANY POSSIBLE PROBS, EVEN THOUGH THERE WAS NO SMOKE VISIBLE IN THE COCKPIT. THE CREW THEN NOTIFIED TRACON OF THE SIT, BUT DID NOT DECLARE AN EMER. OXYGEN WAS USED ALL THE WAY TO LNDG. AFTER LNDG, THE OIL ODOR SEEMED TO DECREASE RAPIDLY, WITH HARDLY ANY ODOR IN THE COCKPIT AFTER SHUTDOWN. MAINT AND THE CHIEF PLT WERE BRIEFED OF THE SIT. HUMAN PERFORMANCE CONSIDERATIONS: ONE COULD SAY THAT THE PERCEIVED INNOCENCE OF THE SIT COULD HAVE BEEN AN ERROR IN JUDGEMENT. THE CONDITION OF THE AIR CONDITIONING SYS, HAVING BEEN A RECURRING PROB, CAUSED THE CAPT TO ASSUME THAT THERE WASN'T ANY GREATER PROB THAN JUST AN ANOMALY WITH THE R PACK, AND THAT TO CONTINUE THE FLT WAS SAFE. AFTER LOOKING AT THE SIT AND OBSERVING THE EVENTUAL RESULT OF THE DECISION MADE TO CONTINUE, THIS PROBABLY WASN'T THE RIGHT CHOICE. THERE WAS MORE TO THE PROB THAN EITHER THE CREW OR MAINT WERE AWARE OF. THE INACTION OF MAINT TO CORRECT THE PROB PROMPTLY ALSO PLAYED A BIG PART IN CONTRIBUTING TO THE SIT. THEY CONTINUALLY FORCED THE ACFT BACK INTO SVC WITHOUT PROPERLY DIAGNOSING THE PROB, THEREFORE, PUTTING THE CREW AND PAX AT RISK. THE CREW'S PERFORMANCE AND ABILITY TO PROPERLY ASSESS THE SIT WERE DIMINISHED BY THE FACT THAT THERE WAS REALLY NO CONCERN OF THE PROB WITH THE AIR CONDITIONING SYS BY MAINT. THIS LED TO THE CREW MAKING INCORRECT JUDGEMENTS WITH REGARDS TO THE SAFETY OF THE FLT.

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.