Narrative:

On taxi out from dfw, our flight to tpa, an large transport. In back of us a widebody transport asked us to come up company mtc frequency. On that frequency he advised us that whenever we stopped we spilled a fluid underneath the left engine. He said he didn't know anything about the large transport and asked about us. I advised him there are a number of drains there and during engine shutdown there is fluid that drains out there. He then repeated that it appears that every time we stop it appears that fluid comes out under #1. I and the captain checked all engine instruments, hydraulics, fuel flow and oil qty and pressure--everything was normal. I advised the widebody transport that everything was normal up here. Another few mins went by before takeoff and all engine systems were normal. I asked the captain to make a tight turn on taxiway to line up with runway to check to see if we could see any fluid. He didn't see any and said he felt there was no problem. I did not disagree with his assessment and we made a normal takeoff. After takeoff roll tower and the widebody transport as well as an air carrier X large transport noticed fluid pouring from engine. We returned to dfw and maintenance discovered fuel leak from fuel start bleed activator (not sure of terminology for this part). In retrospect, had the other aircraft been more definite or there had been any cockpit indication we would have returned to the gate. I did not feel from his description that we had an active leak. It is not abnormal for an large transport to drip fuel on shutdown and I thought maybe this was just sloshing as we stopped on taxiway and not an active leak in progress. In past 2 yrs on the large transport I have noticed a number of fuel drips during walkarounds, notified maintenance, who signed off such leaks as they stop within a specified time frame. I'm not privy to how much fluid the aircraft behind us noticed. To my mind, at the time, it didn't seem as it was enough to be of serious concern. In retrospect I should have insisted on the captain to return to gate for a maintenance inspection. This was the captain's first flight after being checked out on the large transport and I was making special efforts that everything on his side as well as mine was set properly. This may have contributed to me not realizing the potential seriousness of the problem. During engine start in the ramp no wingwalkers or marshaller or tug driver noticed anything unusual. Nothing was noticed during a congested initial taxi out. After taxi in from return the leak was severe. The maintenance personnel speculated a slight leak on taxiout that let go when takeoff power was applied. As a copilot in these situations I feel I'm in a very dubious position. I try not to conflict with the captain's opinion unless an obvious or potentially obvious dangerous situation exists. There are situations that come up fairly often where I would handle things differently than the captain that I am flying with, however for the sake of crew integrity and for a better cockpit atmosphere and ultimately a safer atmosphere, it is better not to second guess until there is a cleancut need for it. In this situation looking back at it with plenty of time to reflect, it is very easy to think that I made a mistake. However, I never felt at the time, nor do I now, that I exposed the airplane or passenger to an unsafe condition. There never was an emergency situation, or unusual cockpit indications. I am glad the other aircraft brought the problem to attention which made others scrutinize our takeoff which is when an actual leak became apparent.

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Original NASA ASRS Text

Title: ACR LGT MADE TKOF AFTER BEING ADVISED BY ANOTHER COMPANY ACFT THAT THE FLT CREW HAD OBSERVED FUEL LEAKING FROM THE #1 ENGINE POD.

Narrative: ON TAXI OUT FROM DFW, OUR FLT TO TPA, AN LGT. IN BACK OF US A WDB ASKED US TO COME UP COMPANY MTC FREQ. ON THAT FREQ HE ADVISED US THAT WHENEVER WE STOPPED WE SPILLED A FLUID UNDERNEATH THE LEFT ENG. HE SAID HE DIDN'T KNOW ANYTHING ABOUT THE LGT AND ASKED ABOUT US. I ADVISED HIM THERE ARE A NUMBER OF DRAINS THERE AND DURING ENG SHUTDOWN THERE IS FLUID THAT DRAINS OUT THERE. HE THEN REPEATED THAT IT APPEARS THAT EVERY TIME WE STOP IT APPEARS THAT FLUID COMES OUT UNDER #1. I AND THE CAPT CHKED ALL ENG INSTRUMENTS, HYDRAULICS, FUEL FLOW AND OIL QTY AND PRESSURE--EVERYTHING WAS NORMAL. I ADVISED THE WDB THAT EVERYTHING WAS NORMAL UP HERE. ANOTHER FEW MINS WENT BY BEFORE TKOF AND ALL ENG SYSTEMS WERE NORMAL. I ASKED THE CAPT TO MAKE A TIGHT TURN ON TXWY TO LINE UP WITH RWY TO CHK TO SEE IF WE COULD SEE ANY FLUID. HE DIDN'T SEE ANY AND SAID HE FELT THERE WAS NO PROB. I DID NOT DISAGREE WITH HIS ASSESSMENT AND WE MADE A NORMAL TKOF. AFTER TKOF ROLL TWR AND THE WDB AS WELL AS AN ACR X LGT NOTICED FLUID POURING FROM ENG. WE RETURNED TO DFW AND MAINT DISCOVERED FUEL LEAK FROM FUEL START BLEED ACTIVATOR (NOT SURE OF TERMINOLOGY FOR THIS PART). IN RETROSPECT, HAD THE OTHER ACFT BEEN MORE DEFINITE OR THERE HAD BEEN ANY COCKPIT INDICATION WE WOULD HAVE RETURNED TO THE GATE. I DID NOT FEEL FROM HIS DESCRIPTION THAT WE HAD AN ACTIVE LEAK. IT IS NOT ABNORMAL FOR AN LGT TO DRIP FUEL ON SHUTDOWN AND I THOUGHT MAYBE THIS WAS JUST SLOSHING AS WE STOPPED ON TXWY AND NOT AN ACTIVE LEAK IN PROGRESS. IN PAST 2 YRS ON THE LGT I HAVE NOTICED A NUMBER OF FUEL DRIPS DURING WALKAROUNDS, NOTIFIED MAINT, WHO SIGNED OFF SUCH LEAKS AS THEY STOP WITHIN A SPECIFIED TIME FRAME. I'M NOT PRIVY TO HOW MUCH FLUID THE ACFT BEHIND US NOTICED. TO MY MIND, AT THE TIME, IT DIDN'T SEEM AS IT WAS ENOUGH TO BE OF SERIOUS CONCERN. IN RETROSPECT I SHOULD HAVE INSISTED ON THE CAPT TO RETURN TO GATE FOR A MAINT INSPECTION. THIS WAS THE CAPT'S FIRST FLT AFTER BEING CHKED OUT ON THE LGT AND I WAS MAKING SPECIAL EFFORTS THAT EVERYTHING ON HIS SIDE AS WELL AS MINE WAS SET PROPERLY. THIS MAY HAVE CONTRIBUTED TO ME NOT REALIZING THE POTENTIAL SERIOUSNESS OF THE PROB. DURING ENG START IN THE RAMP NO WINGWALKERS OR MARSHALLER OR TUG DRIVER NOTICED ANYTHING UNUSUAL. NOTHING WAS NOTICED DURING A CONGESTED INITIAL TAXI OUT. AFTER TAXI IN FROM RETURN THE LEAK WAS SEVERE. THE MAINT PERSONNEL SPECULATED A SLIGHT LEAK ON TAXIOUT THAT LET GO WHEN TKOF PWR WAS APPLIED. AS A COPLT IN THESE SITUATIONS I FEEL I'M IN A VERY DUBIOUS POS. I TRY NOT TO CONFLICT WITH THE CAPT'S OPINION UNLESS AN OBVIOUS OR POTENTIALLY OBVIOUS DANGEROUS SITUATION EXISTS. THERE ARE SITUATIONS THAT COME UP FAIRLY OFTEN WHERE I WOULD HANDLE THINGS DIFFERENTLY THAN THE CAPT THAT I AM FLYING WITH, HOWEVER FOR THE SAKE OF CREW INTEGRITY AND FOR A BETTER COCKPIT ATMOSPHERE AND ULTIMATELY A SAFER ATMOSPHERE, IT IS BETTER NOT TO SECOND GUESS UNTIL THERE IS A CLEANCUT NEED FOR IT. IN THIS SITUATION LOOKING BACK AT IT WITH PLENTY OF TIME TO REFLECT, IT IS VERY EASY TO THINK THAT I MADE A MISTAKE. HOWEVER, I NEVER FELT AT THE TIME, NOR DO I NOW, THAT I EXPOSED THE AIRPLANE OR PAX TO AN UNSAFE CONDITION. THERE NEVER WAS AN EMER SITUATION, OR UNUSUAL COCKPIT INDICATIONS. I AM GLAD THE OTHER ACFT BROUGHT THE PROB TO ATTN WHICH MADE OTHERS SCRUTINIZE OUR TKOF WHICH IS WHEN AN ACTUAL LEAK BECAME APPARENT.

Data retrieved from NASA's ASRS site as of August 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.