|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : zzz.airport|
|Altitude||agl single value : 0|
|Operator||common carrier : air carrier|
|Make Model Name||MD-11|
|Operating Under FAR Part||Part 121|
|Flight Phase||ground : pushback|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : multi engine|
pilot : commercial
pilot : instrument
pilot : atp
|Experience||flight time last 90 days : 45|
flight time total : 4750
flight time type : 500
|Anomaly||aircraft equipment problem : less severe|
maintenance problem : non compliance with mel
non adherence : far
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : detected after the fact|
Flight Crew Human Performance
|Primary Problem||Flight Crew Human Performance|
After pushback and engine start; got a 'gen 3 off' level one alert. Gen 3 electric synoptic showed gen 3 with normal volts and frequencys; but disconnected from the bus. Complied with the QRH. 1 generator reset attempt. Gen 3 remained off line. Spoke with maintenance and looked through the MEL. QRH procedure led me (the captain) to believe that we were done with the event (QRH says: 'if reset attempt is not successful; continue flight with generator inoperative.') first officer and I couldn't find MEL that exactly corresponded to what we were seeing. We spoke with maintenance and came to the conclusion that we would write up the problem and were good to go. WX considerations were made; taking into account degraded approach capability due to 2 versus 3 generator operations (WX not a factor; well above CAT I mins). Unfortunately; I let myself be misled by the differences in wording between the QRH and the MEL; as well as bottom-line rushing to resolve the problem and continue our taxi from the ramp. In retrospect; I clearly made an error. The appropriate MEL; while somewhat ambiguous; does direct us to disconnect the generator. I found the MEL title somewhat confusing when compared to the alert which is titled integrated drive generators versus gen off. Additionally; the text of the MEL contains the paragraph 'confirm with maintenance that idg should be disconnected.' this seems to suggest that there is leeway as to whether or not the idg must be disconnected; when the rest of the MEL suggests that it is not an option. I say in retrospect; because it seemed at the time that we were not required to disconnect it after consultation with maintenance. Besides our own human factors that prevented us from coming to the correct conclusion; I think that if the MEL wording more closely matched the wording of the QRH and the alerts presented on the system display du; finding the correct MEL would be more certain. I absolutely understand the relationship and applicability of the QRH and the MEL; unfortunately; I misapplied the information that I saw. We had no further problems with the aircraft during flight and gen 3 seems to be a recurrent problem with that plane. The first officer and I were both tired. I had been flying all week and had flipped my circadian rhythms and sleep times several times in the past week. I was averaging 5 hours of interrupted sleep all week. While I felt 'capable' of flying; I was very tired. Combined with self induced pressure to get out of ZZZ2's ground's traffic and tight fuel loads at landing; I let myself make what is now obviously a hasty decision. We should have pulled back into the gate; let maintenance resolve the generator MEL; put on an extra 1000 pounds of fuel; and then continued to our destination.
Original NASA ASRS Text
Title: MD11 CAPTAIN REPORTS GEN #3 NOT COMING ON LINE AFTER ENGINE START. MAINTENANCE IS CONSULTED AND THE FLIGHT DEPARTS WITHOUT DISCONNECTING THE IDG AS MEL COMPLIANCE WOULD REQUIRE.
Narrative: AFTER PUSHBACK AND ENG START; GOT A 'GEN 3 OFF' LEVEL ONE ALERT. GEN 3 ELECTRIC SYNOPTIC SHOWED GEN 3 WITH NORMAL VOLTS AND FREQS; BUT DISCONNECTED FROM THE BUS. COMPLIED WITH THE QRH. 1 GENERATOR RESET ATTEMPT. GEN 3 REMAINED OFF LINE. SPOKE WITH MAINT AND LOOKED THROUGH THE MEL. QRH PROC LED ME (THE CAPT) TO BELIEVE THAT WE WERE DONE WITH THE EVENT (QRH SAYS: 'IF RESET ATTEMPT IS NOT SUCCESSFUL; CONTINUE FLT WITH GENERATOR INOP.') FO AND I COULDN'T FIND MEL THAT EXACTLY CORRESPONDED TO WHAT WE WERE SEEING. WE SPOKE WITH MAINT AND CAME TO THE CONCLUSION THAT WE WOULD WRITE UP THE PROB AND WERE GOOD TO GO. WX CONSIDERATIONS WERE MADE; TAKING INTO ACCOUNT DEGRADED APCH CAPABILITY DUE TO 2 VERSUS 3 GENERATOR OPS (WX NOT A FACTOR; WELL ABOVE CAT I MINS). UNFORTUNATELY; I LET MYSELF BE MISLED BY THE DIFFERENCES IN WORDING BTWN THE QRH AND THE MEL; AS WELL AS BOTTOM-LINE RUSHING TO RESOLVE THE PROB AND CONTINUE OUR TAXI FROM THE RAMP. IN RETROSPECT; I CLRLY MADE AN ERROR. THE APPROPRIATE MEL; WHILE SOMEWHAT AMBIGUOUS; DOES DIRECT US TO DISCONNECT THE GENERATOR. I FOUND THE MEL TITLE SOMEWHAT CONFUSING WHEN COMPARED TO THE ALERT WHICH IS TITLED INTEGRATED DRIVE GENERATORS VERSUS GEN OFF. ADDITIONALLY; THE TEXT OF THE MEL CONTAINS THE PARAGRAPH 'CONFIRM WITH MAINT THAT IDG SHOULD BE DISCONNECTED.' THIS SEEMS TO SUGGEST THAT THERE IS LEEWAY AS TO WHETHER OR NOT THE IDG MUST BE DISCONNECTED; WHEN THE REST OF THE MEL SUGGESTS THAT IT IS NOT AN OPTION. I SAY IN RETROSPECT; BECAUSE IT SEEMED AT THE TIME THAT WE WERE NOT REQUIRED TO DISCONNECT IT AFTER CONSULTATION WITH MAINT. BESIDES OUR OWN HUMAN FACTORS THAT PREVENTED US FROM COMING TO THE CORRECT CONCLUSION; I THINK THAT IF THE MEL WORDING MORE CLOSELY MATCHED THE WORDING OF THE QRH AND THE ALERTS PRESENTED ON THE SYS DISPLAY DU; FINDING THE CORRECT MEL WOULD BE MORE CERTAIN. I ABSOLUTELY UNDERSTAND THE RELATIONSHIP AND APPLICABILITY OF THE QRH AND THE MEL; UNFORTUNATELY; I MISAPPLIED THE INFO THAT I SAW. WE HAD NO FURTHER PROBS WITH THE ACFT DURING FLT AND GEN 3 SEEMS TO BE A RECURRENT PROB WITH THAT PLANE. THE FO AND I WERE BOTH TIRED. I HAD BEEN FLYING ALL WEEK AND HAD FLIPPED MY CIRCADIAN RHYTHMS AND SLEEP TIMES SEVERAL TIMES IN THE PAST WEEK. I WAS AVERAGING 5 HRS OF INTERRUPTED SLEEP ALL WEEK. WHILE I FELT 'CAPABLE' OF FLYING; I WAS VERY TIRED. COMBINED WITH SELF INDUCED PRESSURE TO GET OUT OF ZZZ2'S GND'S TFC AND TIGHT FUEL LOADS AT LNDG; I LET MYSELF MAKE WHAT IS NOW OBVIOUSLY A HASTY DECISION. WE SHOULD HAVE PULLED BACK INTO THE GATE; LET MAINT RESOLVE THE GENERATOR MEL; PUT ON AN EXTRA 1000 LBS OF FUEL; AND THEN CONTINUED TO OUR DEST.
Data retrieved from NASA's ASRS site as of May 2009 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.