Narrative:

I was cleared to enter the den TCA at 7500' MSL, and told to follow I-25 to I-70, then I-70 to downwind for 26L. While on downwind I was cleared to land. I then put the gear down and 10 degrees of flaps. I noticed the gear came down slower than normal, and the gear pump continued to run. The amp meter showed a heavy discharge, both fuel gauges were on empty, and the cylinder temperature was on 0. I had no green light for the gear. I could see the main gear out the windows and the nose wheel in the wing mirror, but did not know if all 3 wheels were locked down. By this time we were on final for 26L. I extended the emergency gear handle and pumped it several times but still no light. I then called den tower and told them we had an electrical problem and was aborting the landing. When established in climb I again called den tower and told them I would go back to I-25 and follow it north out of the TCA. I had no idea if they could hear me or if I was on radar anymore. By this time all electrical equipment except the radio I called tower on and the transponder were off. Still no light for the gear, no cht, and no fuel indications--and no noise on the radio. We had topped both tanks prior to takeoff and had burned only 20 mins, so fuel was no problem. I did not want to land at den with the possibility of the gear collapsing, so we went back to ft collins-loveland so I had time to try and get the green gear light, and so when we got back to the shop we could fix the alternator. As it turned out, the gear held through landing and taxi and I had no flaps for landing. The alternator was not working at all and the battery was dead.

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Original NASA ASRS Text

Title: ALTERNATOR FAILURE IN FLT.

Narrative: I WAS CLRED TO ENTER THE DEN TCA AT 7500' MSL, AND TOLD TO FOLLOW I-25 TO I-70, THEN I-70 TO DOWNWIND FOR 26L. WHILE ON DOWNWIND I WAS CLRED TO LAND. I THEN PUT THE GEAR DOWN AND 10 DEGS OF FLAPS. I NOTICED THE GEAR CAME DOWN SLOWER THAN NORMAL, AND THE GEAR PUMP CONTINUED TO RUN. THE AMP METER SHOWED A HEAVY DISCHARGE, BOTH FUEL GAUGES WERE ON EMPTY, AND THE CYLINDER TEMP WAS ON 0. I HAD NO GREEN LIGHT FOR THE GEAR. I COULD SEE THE MAIN GEAR OUT THE WINDOWS AND THE NOSE WHEEL IN THE WING MIRROR, BUT DID NOT KNOW IF ALL 3 WHEELS WERE LOCKED DOWN. BY THIS TIME WE WERE ON FINAL FOR 26L. I EXTENDED THE EMER GEAR HANDLE AND PUMPED IT SEVERAL TIMES BUT STILL NO LIGHT. I THEN CALLED DEN TWR AND TOLD THEM WE HAD AN ELECTRICAL PROB AND WAS ABORTING THE LNDG. WHEN ESTABLISHED IN CLB I AGAIN CALLED DEN TWR AND TOLD THEM I WOULD GO BACK TO I-25 AND FOLLOW IT N OUT OF THE TCA. I HAD NO IDEA IF THEY COULD HEAR ME OR IF I WAS ON RADAR ANYMORE. BY THIS TIME ALL ELECTRICAL EQUIP EXCEPT THE RADIO I CALLED TWR ON AND THE XPONDER WERE OFF. STILL NO LIGHT FOR THE GEAR, NO CHT, AND NO FUEL INDICATIONS--AND NO NOISE ON THE RADIO. WE HAD TOPPED BOTH TANKS PRIOR TO TKOF AND HAD BURNED ONLY 20 MINS, SO FUEL WAS NO PROB. I DID NOT WANT TO LAND AT DEN WITH THE POSSIBILITY OF THE GEAR COLLAPSING, SO WE WENT BACK TO FT COLLINS-LOVELAND SO I HAD TIME TO TRY AND GET THE GREEN GEAR LIGHT, AND SO WHEN WE GOT BACK TO THE SHOP WE COULD FIX THE ALTERNATOR. AS IT TURNED OUT, THE GEAR HELD THROUGH LNDG AND TAXI AND I HAD NO FLAPS FOR LNDG. THE ALTERNATOR WAS NOT WORKING AT ALL AND THE BATTERY WAS DEAD.

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.