Narrative:

Air carrier medium large transport arrived night, 1/sat/91. It came in with PIREP stating air conditioning left ram air door light remained on in flight. The door should have closed in flight and the light extinguished. Aircraft was assigned to a fellow mechanic who needed help in correcting the problem. I assisted. We both decided the ram air door actuator was malfunctioning. We decided to defer the item and place an MEL placard on the affected air conditioning pack. In the procedures, it states to lock off the ram air door in the flight open position and to placard the unit not to be used in takeoff or landing and in the rain. I do not remember the exact MEL procedures nor maintenance manual references, but they were followed in order to properly dispatch the aircraft the next day. The aircraft took off, but encountered a flight interruption shortly thereafter and returned to sea, where it was found that the ram air door was pinned in the ground open position instead of the flight open position, which caused the cabin to be filled with smoke. Both of us confirmed that the door was locked our properly. The aircraft landed with no incidents such as an overweight landing or dumping of fuel. The FAA is now conducting an investigation with the person who released the aircraft and signed off the PIREP. I am very concerned about the issue, since I was assisting the mechanic that night. After the landing the problem was fixed, the lock out pin moved to the flight open position and the flight continued with no other incidents. We placarded the left air conditioning pack since we are short of parts at this station, sea.

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Original NASA ASRS Text

Title: MECHANICS REPORT OF AN ACR MLG THAT MADE AN AIR TURN BACK BECAUSE OF SMOKE IN THE CABIN. THE MECHANIC HAD ASSISTED IN MAINTENANCE ACTIVITY NECESSARY TO DISPATCH THE ACFT WITH INOP AIR CONDITIONING PACK AND POSTFLT INSPECTION REVEALED THAT THE INLET DOOR HAD BEEN SECURED OPEN, WHICH IS THE WRONG POSITION FOR FLT.

Narrative: ACR MLG ARRIVED NIGHT, 1/SAT/91. IT CAME IN WITH PIREP STATING AIR CONDITIONING LEFT RAM AIR DOOR LIGHT REMAINED ON IN FLT. THE DOOR SHOULD HAVE CLOSED IN FLT AND THE LIGHT EXTINGUISHED. ACFT WAS ASSIGNED TO A FELLOW MECH WHO NEEDED HELP IN CORRECTING THE PROB. I ASSISTED. WE BOTH DECIDED THE RAM AIR DOOR ACTUATOR WAS MALFUNCTIONING. WE DECIDED TO DEFER THE ITEM AND PLACE AN MEL PLACARD ON THE AFFECTED AIR CONDITIONING PACK. IN THE PROCS, IT STATES TO LOCK OFF THE RAM AIR DOOR IN THE FLT OPEN POS AND TO PLACARD THE UNIT NOT TO BE USED IN TKOF OR LNDG AND IN THE RAIN. I DO NOT REMEMBER THE EXACT MEL PROCS NOR MAINT MANUAL REFS, BUT THEY WERE FOLLOWED IN ORDER TO PROPERLY DISPATCH THE ACFT THE NEXT DAY. THE ACFT TOOK OFF, BUT ENCOUNTERED A FLT INTERRUPTION SHORTLY THEREAFTER AND RETURNED TO SEA, WHERE IT WAS FOUND THAT THE RAM AIR DOOR WAS PINNED IN THE GND OPEN POS INSTEAD OF THE FLT OPEN POS, WHICH CAUSED THE CABIN TO BE FILLED WITH SMOKE. BOTH OF US CONFIRMED THAT THE DOOR WAS LOCKED OUR PROPERLY. THE ACFT LANDED WITH NO INCIDENTS SUCH AS AN OVERWEIGHT LNDG OR DUMPING OF FUEL. THE FAA IS NOW CONDUCTING AN INVESTIGATION WITH THE PERSON WHO RELEASED THE ACFT AND SIGNED OFF THE PIREP. I AM VERY CONCERNED ABOUT THE ISSUE, SINCE I WAS ASSISTING THE MECH THAT NIGHT. AFTER THE LNDG THE PROB WAS FIXED, THE LOCK OUT PIN MOVED TO THE FLT OPEN POS AND THE FLT CONTINUED WITH NO OTHER INCIDENTS. WE PLACARDED THE LEFT AIR CONDITIONING PACK SINCE WE ARE SHORT OF PARTS AT THIS STATION, SEA.

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.