Narrative:

Airplane change in phoenix before picking up flight to rdu. I went down to the gate a little early with my first officer. While reviewing the paperwork for our flight, I found that MEL 28-1 #1 aft fuel tank boost pump was applied. At that point I reviewed the MEL paperwork attached to the release as our aircraft arrived at the gate. Doing the math quickly, the release showed landing rdu with 8100 pounds of fuel. That appeared to give us above the minimum of 2500 pounds each tank plus reserve. I discussed the MEL with the captain that brought the aircraft in and we both agreed on the intent of the MEL. I said goodbye and we headed on our way to rdu. About 93 mi southwest of lit at FL410, dispatch called and questioned us about what our landing fuel would be in rdu. I informed him we would land rdu with 8300 pounds. He said 'stand by while I do some calculations.' a few mins later he came back and said, 'based on his calculations using MEL 28-1 fuel limits, we would land rdu with 4300 pounds usable.' he then gave me a basic description of how he came up with that minimum landing fuel load and asked if I agreed. I picked up the MEL paperwork again and reviewed it. It seemed that his calculations were correct. However, I was not comfortable landing rdu with minimum fuel and neither was he (dispatch). We had a brief conversation about various diversion points and I elected to use lit based on proximity and VFR WX conditions. We landed in lit with 14000 pounds fuel. Once on the ground at lit, I called dispatch to find out exactly where we went wrong. We then reviewed the MEL in detail. My next question to him was how did dispatch miscalculate this also? In asking this question, it was my thought at the time to better understand how this chain of errors could have been avoided sooner. He then explained that the computer program for the 700 aircraft calculating this MEL 28-1 required manual inputs for the necessary fuel additives, and that the manual inputs were not properly applied. In summary of the situation: in retrospect, I made an error in thinking that I understood MEL 28-1. In the future, with an MEL that is complex or vague in nature, I will contact dispatch and/or maintenance control to make sure that I have a full understanding of the MEL in question. I sincerely believe that if I would have contacted dispatch to verify that the MEL was being applied properly, this would have triggered a deeper analysis of the fuel load required and the error would have been caught. Through my conversation with the dispatcher, he explained that this MEL was sometimes used in training because it is vague and more complex than it appears. I believe that many MEL's are poorly written -- this one being a prime example. With the MEL's that are complex and more critical in nature, could verbiage and explanation be created to ensure that they are clrer and more user friendly on the line? Note: my first officer was brand new and did a fine job throughout the situation. I truly appreciated and commend his CRM skills.

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Original NASA ASRS Text

Title: B737-700 CREW LANDED SHORT FOR FUEL BECAUSE THEY DID NOT HAVE ENOUGH FUEL TO COMPLY WITH AN MEL'ED FUEL PUMP FAILURE.

Narrative: AIRPLANE CHANGE IN PHOENIX BEFORE PICKING UP FLT TO RDU. I WENT DOWN TO THE GATE A LITTLE EARLY WITH MY FO. WHILE REVIEWING THE PAPERWORK FOR OUR FLT, I FOUND THAT MEL 28-1 #1 AFT FUEL TANK BOOST PUMP WAS APPLIED. AT THAT POINT I REVIEWED THE MEL PAPERWORK ATTACHED TO THE RELEASE AS OUR ACFT ARRIVED AT THE GATE. DOING THE MATH QUICKLY, THE RELEASE SHOWED LNDG RDU WITH 8100 LBS OF FUEL. THAT APPEARED TO GIVE US ABOVE THE MINIMUM OF 2500 LBS EACH TANK PLUS RESERVE. I DISCUSSED THE MEL WITH THE CAPT THAT BROUGHT THE ACFT IN AND WE BOTH AGREED ON THE INTENT OF THE MEL. I SAID GOODBYE AND WE HEADED ON OUR WAY TO RDU. ABOUT 93 MI SW OF LIT AT FL410, DISPATCH CALLED AND QUESTIONED US ABOUT WHAT OUR LNDG FUEL WOULD BE IN RDU. I INFORMED HIM WE WOULD LAND RDU WITH 8300 LBS. HE SAID 'STAND BY WHILE I DO SOME CALCULATIONS.' A FEW MINS LATER HE CAME BACK AND SAID, 'BASED ON HIS CALCULATIONS USING MEL 28-1 FUEL LIMITS, WE WOULD LAND RDU WITH 4300 LBS USABLE.' HE THEN GAVE ME A BASIC DESCRIPTION OF HOW HE CAME UP WITH THAT MINIMUM LNDG FUEL LOAD AND ASKED IF I AGREED. I PICKED UP THE MEL PAPERWORK AGAIN AND REVIEWED IT. IT SEEMED THAT HIS CALCULATIONS WERE CORRECT. HOWEVER, I WAS NOT COMFORTABLE LNDG RDU WITH MINIMUM FUEL AND NEITHER WAS HE (DISPATCH). WE HAD A BRIEF CONVERSATION ABOUT VARIOUS DIVERSION POINTS AND I ELECTED TO USE LIT BASED ON PROX AND VFR WX CONDITIONS. WE LANDED IN LIT WITH 14000 LBS FUEL. ONCE ON THE GND AT LIT, I CALLED DISPATCH TO FIND OUT EXACTLY WHERE WE WENT WRONG. WE THEN REVIEWED THE MEL IN DETAIL. MY NEXT QUESTION TO HIM WAS HOW DID DISPATCH MISCALCULATE THIS ALSO? IN ASKING THIS QUESTION, IT WAS MY THOUGHT AT THE TIME TO BETTER UNDERSTAND HOW THIS CHAIN OF ERRORS COULD HAVE BEEN AVOIDED SOONER. HE THEN EXPLAINED THAT THE COMPUTER PROGRAM FOR THE 700 ACFT CALCULATING THIS MEL 28-1 REQUIRED MANUAL INPUTS FOR THE NECESSARY FUEL ADDITIVES, AND THAT THE MANUAL INPUTS WERE NOT PROPERLY APPLIED. IN SUMMARY OF THE SIT: IN RETROSPECT, I MADE AN ERROR IN THINKING THAT I UNDERSTOOD MEL 28-1. IN THE FUTURE, WITH AN MEL THAT IS COMPLEX OR VAGUE IN NATURE, I WILL CONTACT DISPATCH AND/OR MAINT CTL TO MAKE SURE THAT I HAVE A FULL UNDERSTANDING OF THE MEL IN QUESTION. I SINCERELY BELIEVE THAT IF I WOULD HAVE CONTACTED DISPATCH TO VERIFY THAT THE MEL WAS BEING APPLIED PROPERLY, THIS WOULD HAVE TRIGGERED A DEEPER ANALYSIS OF THE FUEL LOAD REQUIRED AND THE ERROR WOULD HAVE BEEN CAUGHT. THROUGH MY CONVERSATION WITH THE DISPATCHER, HE EXPLAINED THAT THIS MEL WAS SOMETIMES USED IN TRAINING BECAUSE IT IS VAGUE AND MORE COMPLEX THAN IT APPEARS. I BELIEVE THAT MANY MEL'S ARE POORLY WRITTEN -- THIS ONE BEING A PRIME EXAMPLE. WITH THE MEL'S THAT ARE COMPLEX AND MORE CRITICAL IN NATURE, COULD VERBIAGE AND EXPLANATION BE CREATED TO ENSURE THAT THEY ARE CLRER AND MORE USER FRIENDLY ON THE LINE? NOTE: MY FO WAS BRAND NEW AND DID A FINE JOB THROUGHOUT THE SIT. I TRULY APPRECIATED AND COMMEND HIS CRM SKILLS.

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.