Narrative:

This report involves being dispatched with a MEL item with a performance penalty and a slush correction. We didn't even know we were illegal until I went to training and spoke to many dispatchers and human factor instructors. We had an EPR guage placarded inoperative. (For the life of me I can't figure out why we take a 20000 pound takeoff hit for an EPR guage. Can someone please tell me?) I truly need to know. After an incident years ago; I set N1 for takeoff; yes the autothrottle aligns the EPR; but EPR can lie in certain conditions. N1; does not lie. When you match up N1s with the N1 on the performance paperwork; you are getting the power you are asking for. Ok; so we are dispatched with the MEL item; the performance paperwork is corrected for the MEL item; but we are dispatched with 6 degrees flaps; and there is ¼ inch of slush reported on the runway. After several conversations with dispatch; he plugs in the data for slush correction. (We no longer have data in our manuals for slush corrections; it also no longer says 11 degrees for 17 degrees flaps for contaminated runway.) so the dispatcher is plugging in 6 degree flap data. I insist on at least 11 degree flaps. He then sends me a performance paperwork for 11 degrees. I then call him and ask are these numbers corrected for the slush correction? He then calls loads and they discuss it; as for some reason they can't get data for the slush correction; in the slush correction format as the MEL penalty takes precedence over the slush. He then tells me the performance paperwork he just sent me; after talking to loads is corrected for slush. So I am verbally told my V speeds are good for ¼ inch slush; although they are not in the format I am used to seeing; they have been manually adjusted and the numbers here are more conservative. In my recurrent training; I spoke with 5 dispatchers (5 different answers for this problem) and the dispatch training department. I was at the dispatch training person's desk and she put me on a conference call with another person. He was the person that does the MEL/performance manual changes etc. We spoke in depth about this problem that occurred; and how we needed to have 'the slush correction format'; otherwise the V speeds are not corrected. They said it is a problem with the MEL and I believe the performance computer system. They said this was specific to the MD80. All other mels worked correctly with the slush corrections and the MEL corrections. Needless to say; when we get numbers from dispatch; and when we talk to them on a cell phone in the cockpit (speaker phone so my first officer and I both heard this) and they assure me even though there is no way to get the correction in the format we are used to seeing due to the MEL correction; but that the numbers we are seeing; corrected for MEL; are also corrected for the slush correction. I need to know that this is good data. I have no way to cross check anymore. When I have basic performance paperwork data; I can go to the charts and be certain that a correction is applied; or not being applied twice; etc. I am now relying on someone else and when I find out the numbers were wrong I am pissed. Very pissed. I am rolling down a slush covered runway at 4000 ft MSL; going 140 KTS; not sitting at a desk with a computer screen in front of me. I have 145 lives trusting me and my first officer. Although the weather outside is on their minds; they know we have been trained correctly and are operating within the parameters of the operating manual. 90 percent of the time we fly there is room for error; but in certain times of our operation; when the stars are aligned…there is no room for error. This was one high speed abort away from a big problem. It needs to be addressed and fixed.

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Original NASA ASRS Text

Title: A MD80 Captain describes an aircraft performance detriment which was not correctly applied for a MEL'ed EPR guage on a slush covered runway requiring a 20;000 pound weight restriction.

Narrative: This report involves being dispatched with a MEL item with a performance penalty and a slush correction. We didn't even know we were illegal until I went to training and spoke to many Dispatchers and Human Factor Instructors. We had an EPR guage placarded inoperative. (For the life of me I can't figure out why we take a 20000 pound takeoff hit for an EPR guage. Can someone PLEASE tell me?) I truly need to know. After an incident years ago; I set N1 for takeoff; yes the autothrottle aligns the EPR; but EPR can lie in certain conditions. N1; does NOT lie. When you match up N1s with the N1 on the performance paperwork; you are getting the power you are asking for. Ok; so we are dispatched with the MEL item; the performance paperwork is corrected for the MEL item; BUT we are dispatched with 6 degrees flaps; and there is ¼ inch of slush reported on the runway. After several conversations with Dispatch; he plugs in the data for slush correction. (We no longer have data in our manuals for slush corrections; it also no longer says 11 degrees for 17 degrees flaps for contaminated runway.) So the Dispatcher is plugging in 6 degree flap data. I insist on at least 11 degree flaps. He then sends me a performance paperwork for 11 degrees. I then call him and ask are these numbers corrected for the slush correction? He then calls Loads and they discuss it; as for some reason they can't get data for the slush correction; in the slush correction format as the MEL penalty takes precedence over the slush. He then tells me the performance paperwork he just sent me; after talking to Loads IS corrected for slush. So I am verbally told my V speeds are good for ¼ inch slush; although they are not in the format I am used to seeing; they have been manually adjusted and the numbers here are more conservative. In my Recurrent Training; I spoke with 5 Dispatchers (5 different answers for this problem) and the Dispatch Training Department. I was at the Dispatch Training person's desk and she put me on a conference call with another person. He was the person that does the MEL/performance manual changes etc. We spoke in depth about this problem that occurred; and how we needed to have 'the slush correction format'; otherwise the V speeds ARE NOT corrected. They said it is a problem with the MEL and I believe the Performance Computer system. They said this was specific to the MD80. All other MELs worked correctly with the slush corrections and the MEL corrections. Needless to say; when we get numbers from Dispatch; and when we talk to them on a cell phone in the cockpit (speaker phone so my First Officer and I both heard this) and they assure me even though there is no way to get the correction in the format we are used to seeing due to the MEL correction; but that the numbers we are seeing; corrected for MEL; are also corrected for the slush correction. I NEED to know that this is GOOD data. I have no way to cross check anymore. When I have basic performance paperwork data; I can go to the charts and be certain that a correction is applied; or not being applied twice; etc. I am now relying on someone else and when I find out the numbers were wrong I am pissed. Very pissed. I am rolling down a slush covered runway at 4000 FT MSL; going 140 KTS; not sitting at a desk with a computer screen in front of me. I have 145 lives trusting me and my First Officer. Although the weather outside is on their minds; they know we have been trained correctly and are operating within the parameters of the operating manual. 90 percent of the time we fly there is room for error; but in certain times of our operation; when the stars are aligned…there is no room for error. This was one high speed abort away from a big problem. It needs to be addressed and fixed.

Data retrieved from NASA's ASRS site as of April 2012 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.