Narrative:

I was on a trip of approximately 75 mi from N80 (ocean city, md) to my home base at mtn (martin state airport). Intermittently for the past 2 days I had noticed the alternator light comes on in flight, with a concurrent discharge in amps. Nonetheless, I would achieve the alternator again on the ground and the battery would show a heavy charge. Upon takeoff N80, the alternator 'out' light went on and stayed on. I was cruising at 160 KTS, approximately. At 20 mi from mtn, I was monitoring the martin tower frequency (123.3). At 15 mi out (southeast) I attempted to contact mtn tower, I found I had no communications at all. I dropped my gear but achieved only an amber warning light. I attempted to finish lowering the gear by hand and ran the manual against the stops, but still had no green lights. I had no flaps and it was apparent to me as I approached on a left downwind the runway 14 (heading 340), that I had lost all electrical power. I decided to attempt a landing, realizing there were other aircraft in the area and realizing I had not been able to contact the tower for entry into the control zone. I realized that the tower has no radar or transponder ability so it was not feasible, I judged, to input the emergency squawk. I was on final to 14, but high, intending to land long just in case when an small aircraft took the active. I banked to the right for a go around and suddenly regained communications in strength. I communicated hurriedly with the tower who advised a right downwind clear to land runway 14. As I turned away from the tower going to downwind 14, I lost all electrical power again. I landed hot without flaps but with no damage or injury, avoiding all other aircraft. I taxied to maintenance on the ramp for repairs. In retrospect, I believe that immediate action should have been taken by me to correct the source of the failed alternator rather than flying with the alternator out, draining the battery. The battery was less than a month old, but still did not provide sufficient amperage to allow me to finish the flight safety. Callback conversation with reporter revealed the following: reporter states that after arrival at mtn airport he took the aircraft to the maintenance department and they found a loose ground wire which, when reconnected, did act properly and charge the battery. Even though the battery was new it had not held the charge as well as could be expected. Later that week, even though the alternator was now functioning, the battery died. Reporter replaced battery and had entire system rechecked. Pilot states that never again will he ignore symptomatic signals on his aircraft. No flight crew/ATC review or word from any other agency re this event.

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Original NASA ASRS Text

Title: EMERGENCY LNDG AT TWR CONTROLLED ARPT. NO ELECTRICAL POWER, NO RADIO.

Narrative: I WAS ON A TRIP OF APPROX 75 MI FROM N80 (OCEAN CITY, MD) TO MY HOME BASE AT MTN (MARTIN STATE ARPT). INTERMITTENTLY FOR THE PAST 2 DAYS I HAD NOTICED THE ALTERNATOR LIGHT COMES ON IN FLT, WITH A CONCURRENT DISCHARGE IN AMPS. NONETHELESS, I WOULD ACHIEVE THE ALTERNATOR AGAIN ON THE GND AND THE BATTERY WOULD SHOW A HEAVY CHARGE. UPON TKOF N80, THE ALTERNATOR 'OUT' LIGHT WENT ON AND STAYED ON. I WAS CRUISING AT 160 KTS, APPROX. AT 20 MI FROM MTN, I WAS MONITORING THE MARTIN TWR FREQ (123.3). AT 15 MI OUT (SE) I ATTEMPTED TO CONTACT MTN TWR, I FOUND I HAD NO COMS AT ALL. I DROPPED MY GEAR BUT ACHIEVED ONLY AN AMBER WARNING LIGHT. I ATTEMPTED TO FINISH LOWERING THE GEAR BY HAND AND RAN THE MANUAL AGAINST THE STOPS, BUT STILL HAD NO GREEN LIGHTS. I HAD NO FLAPS AND IT WAS APPARENT TO ME AS I APCHED ON A LEFT DOWNWIND THE RWY 14 (HEADING 340), THAT I HAD LOST ALL ELECTRICAL POWER. I DECIDED TO ATTEMPT A LNDG, REALIZING THERE WERE OTHER ACFT IN THE AREA AND REALIZING I HAD NOT BEEN ABLE TO CONTACT THE TWR FOR ENTRY INTO THE CTL ZONE. I REALIZED THAT THE TWR HAS NO RADAR OR XPONDER ABILITY SO IT WAS NOT FEASIBLE, I JUDGED, TO INPUT THE EMER SQUAWK. I WAS ON FINAL TO 14, BUT HIGH, INTENDING TO LAND LONG JUST IN CASE WHEN AN SMA TOOK THE ACTIVE. I BANKED TO THE RIGHT FOR A GO AROUND AND SUDDENLY REGAINED COMS IN STRENGTH. I COMMUNICATED HURRIEDLY WITH THE TWR WHO ADVISED A RIGHT DOWNWIND CLEAR TO LAND RWY 14. AS I TURNED AWAY FROM THE TWR GOING TO DOWNWIND 14, I LOST ALL ELECTRICAL POWER AGAIN. I LANDED HOT WITHOUT FLAPS BUT WITH NO DAMAGE OR INJURY, AVOIDING ALL OTHER ACFT. I TAXIED TO MAINT ON THE RAMP FOR REPAIRS. IN RETROSPECT, I BELIEVE THAT IMMEDIATE ACTION SHOULD HAVE BEEN TAKEN BY ME TO CORRECT THE SOURCE OF THE FAILED ALTERNATOR RATHER THAN FLYING WITH THE ALTERNATOR OUT, DRAINING THE BATTERY. THE BATTERY WAS LESS THAN A MONTH OLD, BUT STILL DID NOT PROVIDE SUFFICIENT AMPERAGE TO ALLOW ME TO FINISH THE FLT SAFETY. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: REPORTER STATES THAT AFTER ARR AT MTN ARPT HE TOOK THE ACFT TO THE MAINT DEPT AND THEY FOUND A LOOSE GND WIRE WHICH, WHEN RECONNECTED, DID ACT PROPERLY AND CHARGE THE BATTERY. EVEN THOUGH THE BATTERY WAS NEW IT HAD NOT HELD THE CHARGE AS WELL AS COULD BE EXPECTED. LATER THAT WEEK, EVEN THOUGH THE ALTERNATOR WAS NOW FUNCTIONING, THE BATTERY DIED. REPORTER REPLACED BATTERY AND HAD ENTIRE SYSTEM RECHECKED. PLT STATES THAT NEVER AGAIN WILL HE IGNORE SYMPTOMATIC SIGNALS ON HIS ACFT. NO FLT CREW/ATC REVIEW OR WORD FROM ANY OTHER AGENCY RE THIS EVENT.

Data retrieved from NASA's ASRS site as of August 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.