Narrative:

The aircraft was already pwred. I proceeded downstairs to maintenance to inquire and inspect the logbook. There were numerous write-ups from the inbound arrival the evening before, including left ice protect temperature high, stall indication failure, inoperative transponder and automatic ground spoiler inoperative. 2 hours passed with no activity so I inquired about our status. I was told they were waiting for parts. Some work started approximately 1/2 hour later. At approximately XE00 I contacted dispatcher mr X to inquire if he knew anything about the parts. He implied 'I am unaware of the total situation there and am experiencing some communication difficulties with maintenance control.' he asked me to keep him abreast at my end. I agreed. Mr X asked if I would be willing to fly the airplane to ZZZ2 with the MEL items: automatic ground spoiler inoperative and inoperative transponder #1 and #2 if he could get FAA permission. At approximately XF00, I observed at the cockpit door, a mechanic testing the transponder. Although the test gear was plugged into a jetway outlet, the screen on the unit on each test indicated test failed, battery low. Seconds later, he exited the cabin and said 'it tests ok, you're good to go.' needless to say, we looked at each other with a little astonishment. I questioned him about all the failed tests I observed. He stated 'I got 1 good test before it went dead.' we accomplished a second cockpit preflight and called dispatch for a new release and WX package. It was approaching XH00 when we were told there was additional work to do but another shift change was occurring along with lunch hour so no further work was being conducted and they were now waiting for additional test equipment. At approximately XJ00 the new probes were installed, tested and safety-wired. We did the preflight check, after which maintenance informed us we were not going to go anywhere soon because maintenance control advised them to repair the #2 transponder so the aircraft would not be down in ZZZ2. They also wanted to check the ground shift switches and relays. This took an additional 2+ hours. In the meantime, maintenance installed a pitot static test system during these 2+ hours mentioned above. I was told they could not get the pitot static test machine to function, so we were back to the original plan of departing with 1 transponder with no mode C. The pitot test was for the mode C calibration. We did our third cockpit check. At XK38 we released the brakes and began to push back. Taxi out was normal and our takeoff and initial climb were normal. After passing approximately 15000 ft, ATC advised us to recycle our transponder, as they lost radar contact. We obliged. They informed us that the transponder appeared not to be functioning. I called ZZZ operations to advise them that the transponder once again failed so they could plan ahead when the aircraft arrived in ZZZ2. Because of upper air turbulence and 25 less KTS on the nose, we elected to level off at FL240. Approximately 40 mi east of ZZZ4 VOR, we noticed a flickering of the stall indication failure annunciator light. We followed the communication procedure but because it was intermittent, that procedure could not be applied. I talked to dispatch per the company operations manual to advise them of the indication. Approximately 5 mins later, the light was illuminated steady for the most part but still once in a while flashing. When over the ZZZ4 VOR the thunderstorm lights began to flash. I looked to the overhead panel and noticed the right generator load meter pegging at 150% approximately every 10 seconds. I immediately selected the APU buss switches off and started the APU. Shortly thereafter, the load meter was pegging to 150% every 2-3 seconds. Volts and frequencys appeared normal. I closed the APU buss switch for the right side and selected the right generator off. The APU load meter was pegging the same as the right generator load meter. First officer expressed HSI concern and I agreed. I told him to continue to fly the aircraft, declare an emergency with ATC and asked them for the nearest suitable airport with 7000 ft in case we need to divert if a major electrical problem developed. I told him I would be off #1 to talk to dispatch. I advised dispatch we had an electrical problem and we exercised emergency authority/authorized andwere considering diversion. We requested direct ZZZ2. I then asked dispatch to get maintenance control for suggestions. I asked if he would concur with isolating the right electrical system and continuing with the left system functioning. He agreed. I took control of the aircraft. We selected the automatic xtie switch to the 'open' position and shut off the right generator. All remaining system were now stable. We were handed off to ZZZ2 approach. We instructed them of our electrical degradation requested the equipment. We landed on runway 4R and taxied directly to the hangar. The system slowly degrading without with a specific sequence, load surges, lights blinking, etc, I had only one intention, land safely with no fire. This was accomplished successfully. Maintenance advised me that there was a slow progressive failure of the ground shift mechanism. This is in contract to an outright failure with the obvious clues. My thoughts are the rapid intermittent right electrical load fluctuations before we isolated the right electrical system was more than likely the right pack cooling fan cycling on an doff.

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Original NASA ASRS Text

Title: DC9 CREW WAS REQUIRED TO MAKE AN EMER LNDG BECAUSE OF IMPROPERLY SIGNED OFF MAINT DISCREPANCIES.

Narrative: THE ACFT WAS ALREADY PWRED. I PROCEEDED DOWNSTAIRS TO MAINT TO INQUIRE AND INSPECT THE LOGBOOK. THERE WERE NUMEROUS WRITE-UPS FROM THE INBOUND ARR THE EVENING BEFORE, INCLUDING L ICE PROTECT TEMP HIGH, STALL INDICATION FAILURE, INOP XPONDER AND AUTO GND SPOILER INOP. 2 HRS PASSED WITH NO ACTIVITY SO I INQUIRED ABOUT OUR STATUS. I WAS TOLD THEY WERE WAITING FOR PARTS. SOME WORK STARTED APPROX 1/2 HR LATER. AT APPROX XE00 I CONTACTED DISPATCHER MR X TO INQUIRE IF HE KNEW ANYTHING ABOUT THE PARTS. HE IMPLIED 'I AM UNAWARE OF THE TOTAL SIT THERE AND AM EXPERIENCING SOME COM DIFFICULTIES WITH MAINT CTL.' HE ASKED ME TO KEEP HIM ABREAST AT MY END. I AGREED. MR X ASKED IF I WOULD BE WILLING TO FLY THE AIRPLANE TO ZZZ2 WITH THE MEL ITEMS: AUTO GND SPOILER INOP AND INOP XPONDER #1 AND #2 IF HE COULD GET FAA PERMISSION. AT APPROX XF00, I OBSERVED AT THE COCKPIT DOOR, A MECH TESTING THE XPONDER. ALTHOUGH THE TEST GEAR WAS PLUGGED INTO A JETWAY OUTLET, THE SCREEN ON THE UNIT ON EACH TEST INDICATED TEST FAILED, BATTERY LOW. SECONDS LATER, HE EXITED THE CABIN AND SAID 'IT TESTS OK, YOU'RE GOOD TO GO.' NEEDLESS TO SAY, WE LOOKED AT EACH OTHER WITH A LITTLE ASTONISHMENT. I QUESTIONED HIM ABOUT ALL THE FAILED TESTS I OBSERVED. HE STATED 'I GOT 1 GOOD TEST BEFORE IT WENT DEAD.' WE ACCOMPLISHED A SECOND COCKPIT PREFLT AND CALLED DISPATCH FOR A NEW RELEASE AND WX PACKAGE. IT WAS APCHING XH00 WHEN WE WERE TOLD THERE WAS ADDITIONAL WORK TO DO BUT ANOTHER SHIFT CHANGE WAS OCCURRING ALONG WITH LUNCH HR SO NO FURTHER WORK WAS BEING CONDUCTED AND THEY WERE NOW WAITING FOR ADDITIONAL TEST EQUIP. AT APPROX XJ00 THE NEW PROBES WERE INSTALLED, TESTED AND SAFETY-WIRED. WE DID THE PREFLT CHK, AFTER WHICH MAINT INFORMED US WE WERE NOT GOING TO GO ANYWHERE SOON BECAUSE MAINT CTL ADVISED THEM TO REPAIR THE #2 XPONDER SO THE ACFT WOULD NOT BE DOWN IN ZZZ2. THEY ALSO WANTED TO CHK THE GND SHIFT SWITCHES AND RELAYS. THIS TOOK AN ADDITIONAL 2+ HRS. IN THE MEANTIME, MAINT INSTALLED A PITOT STATIC TEST SYS DURING THESE 2+ HRS MENTIONED ABOVE. I WAS TOLD THEY COULD NOT GET THE PITOT STATIC TEST MACHINE TO FUNCTION, SO WE WERE BACK TO THE ORIGINAL PLAN OF DEPARTING WITH 1 XPONDER WITH NO MODE C. THE PITOT TEST WAS FOR THE MODE C CALIBRATION. WE DID OUR THIRD COCKPIT CHK. AT XK38 WE RELEASED THE BRAKES AND BEGAN TO PUSH BACK. TAXI OUT WAS NORMAL AND OUR TKOF AND INITIAL CLB WERE NORMAL. AFTER PASSING APPROX 15000 FT, ATC ADVISED US TO RECYCLE OUR XPONDER, AS THEY LOST RADAR CONTACT. WE OBLIGED. THEY INFORMED US THAT THE XPONDER APPEARED NOT TO BE FUNCTIONING. I CALLED ZZZ OPS TO ADVISE THEM THAT THE XPONDER ONCE AGAIN FAILED SO THEY COULD PLAN AHEAD WHEN THE ACFT ARRIVED IN ZZZ2. BECAUSE OF UPPER AIR TURB AND 25 LESS KTS ON THE NOSE, WE ELECTED TO LEVEL OFF AT FL240. APPROX 40 MI E OF ZZZ4 VOR, WE NOTICED A FLICKERING OF THE STALL INDICATION FAILURE ANNUNCIATOR LIGHT. WE FOLLOWED THE COM PROC BUT BECAUSE IT WAS INTERMITTENT, THAT PROC COULD NOT BE APPLIED. I TALKED TO DISPATCH PER THE COMPANY OPS MANUAL TO ADVISE THEM OF THE INDICATION. APPROX 5 MINS LATER, THE LIGHT WAS ILLUMINATED STEADY FOR THE MOST PART BUT STILL ONCE IN A WHILE FLASHING. WHEN OVER THE ZZZ4 VOR THE TSTM LIGHTS BEGAN TO FLASH. I LOOKED TO THE OVERHEAD PANEL AND NOTICED THE R GENERATOR LOAD METER PEGGING AT 150% APPROX EVERY 10 SECONDS. I IMMEDIATELY SELECTED THE APU BUSS SWITCHES OFF AND STARTED THE APU. SHORTLY THEREAFTER, THE LOAD METER WAS PEGGING TO 150% EVERY 2-3 SECONDS. VOLTS AND FREQS APPEARED NORMAL. I CLOSED THE APU BUSS SWITCH FOR THE R SIDE AND SELECTED THE R GENERATOR OFF. THE APU LOAD METER WAS PEGGING THE SAME AS THE R GENERATOR LOAD METER. FO EXPRESSED HSI CONCERN AND I AGREED. I TOLD HIM TO CONTINUE TO FLY THE ACFT, DECLARE AN EMER WITH ATC AND ASKED THEM FOR THE NEAREST SUITABLE ARPT WITH 7000 FT IN CASE WE NEED TO DIVERT IF A MAJOR ELECTRICAL PROB DEVELOPED. I TOLD HIM I WOULD BE OFF #1 TO TALK TO DISPATCH. I ADVISED DISPATCH WE HAD AN ELECTRICAL PROB AND WE EXERCISED EMER AUTH ANDWERE CONSIDERING DIVERSION. WE REQUESTED DIRECT ZZZ2. I THEN ASKED DISPATCH TO GET MAINT CTL FOR SUGGESTIONS. I ASKED IF HE WOULD CONCUR WITH ISOLATING THE R ELECTRICAL SYS AND CONTINUING WITH THE L SYS FUNCTIONING. HE AGREED. I TOOK CTL OF THE ACFT. WE SELECTED THE AUTO XTIE SWITCH TO THE 'OPEN' POS AND SHUT OFF THE R GENERATOR. ALL REMAINING SYS WERE NOW STABLE. WE WERE HANDED OFF TO ZZZ2 APCH. WE INSTRUCTED THEM OF OUR ELECTRICAL DEGRADATION REQUESTED THE EQUIP. WE LANDED ON RWY 4R AND TAXIED DIRECTLY TO THE HANGAR. THE SYS SLOWLY DEGRADING WITHOUT WITH A SPECIFIC SEQUENCE, LOAD SURGES, LIGHTS BLINKING, ETC, I HAD ONLY ONE INTENTION, LAND SAFELY WITH NO FIRE. THIS WAS ACCOMPLISHED SUCCESSFULLY. MAINT ADVISED ME THAT THERE WAS A SLOW PROGRESSIVE FAILURE OF THE GND SHIFT MECHANISM. THIS IS IN CONTRACT TO AN OUTRIGHT FAILURE WITH THE OBVIOUS CLUES. MY THOUGHTS ARE THE RAPID INTERMITTENT R ELECTRICAL LOAD FLUCTUATIONS BEFORE WE ISOLATED THE R ELECTRICAL SYS WAS MORE THAN LIKELY THE R PACK COOLING FAN CYCLING ON AN DOFF.

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.