Narrative:

After start up, the ammeter showed a discharge. Increasing the power from idle to 1700 RPM, the needle was well to the right then settled back down to 1/2 needle width right of center. Shortly after takeoff approach reported losing our mode C. Recycling did not work. The reply light on the transponder appeared dim about 30 mins into the flight and seemed infrequent. Passing the emp VOR and continuing east seemed uneventful. Somewhere between emp and bum vors we lost radios one by one. I think the transponder went first, then the navigation navcom, then #2 navcom. We killed these to conserve battery power, wing the VFR only LORAN and the hand held communication radio. Then we lost the LORAN and the hand held communication as it's batteries went dead. We never did establish contact on the hand held communication. We squawked 7700/7600, but were skeptical if it was received. We reviewed the ft's and sa's of airports around us and found that most were reporting IFR or MVFR. Our destination, I69 was hundreds of mi ahead. WX was reported as slightly worse. Our condition could only worsen. At present we still had fuel gauges, auxiliary fuel pump, engine gauges and maybe gear extension capability. Winds aloft were 30-40 KTS, quartering tailwind. We had only xed two chkpoints, and were just establishing ground speed and wind correction angle when the navigation loss occurred. My student and I elected to descend from 7000' assigned, to 2700' the MEA, to see if we could achieve VMC and land. At 2700' we had ground contact through breaks in the overcast. The sectional chart said the highest obstacle in our area was 1500'. We descended through a hole to 1600' and found ourselves with about 8 mi visibility and in and out of the bases. We followed a paved road briefly and came to a town. Based on our last known position and dead reckoning we determined this to be clinton, mo. Manual landing gear extension was necessary and flap extension was impossible. Immediately after landing we called columbia, mo, AFSS to inform ZKC of our situation. I called my wife, then the phone rang in the airport office, ZKC was calling to determine our status. Cou AFSS had not yet called them. The problem was a shorted filter to suppress generator noise in the avionics. It completely drained the electrical system. At all times the ammeter showed a slight positive charge. In hindsight, the only think I regret is not asking the student how fresh the hand held batteries were prior to the flight.

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Original NASA ASRS Text

Title: COMM AND NAV EQUIPMENT FAILED SHORTLY AFTER START OF FLT IN IMC CONDITIONS. FLT DESCENDED TO VFR AND LANDED AT FIRST IDENTIFIED ARPT.

Narrative: AFTER START UP, THE AMMETER SHOWED A DISCHARGE. INCREASING THE PWR FROM IDLE TO 1700 RPM, THE NEEDLE WAS WELL TO THE R THEN SETTLED BACK DOWN TO 1/2 NEEDLE WIDTH R OF CTR. SHORTLY AFTER TKOF APCH RPTED LOSING OUR MODE C. RECYCLING DID NOT WORK. THE REPLY LIGHT ON THE XPONDER APPEARED DIM ABOUT 30 MINS INTO THE FLT AND SEEMED INFREQUENT. PASSING THE EMP VOR AND CONTINUING E SEEMED UNEVENTFUL. SOMEWHERE BTWN EMP AND BUM VORS WE LOST RADIOS ONE BY ONE. I THINK THE XPONDER WENT FIRST, THEN THE NAV NAVCOM, THEN #2 NAVCOM. WE KILLED THESE TO CONSERVE BATTERY PWR, WING THE VFR ONLY LORAN AND THE HAND HELD COM RADIO. THEN WE LOST THE LORAN AND THE HAND HELD COM AS IT'S BATTERIES WENT DEAD. WE NEVER DID ESTABLISH CONTACT ON THE HAND HELD COM. WE SQUAWKED 7700/7600, BUT WERE SKEPTICAL IF IT WAS RECEIVED. WE REVIEWED THE FT'S AND SA'S OF ARPTS AROUND US AND FOUND THAT MOST WERE RPTING IFR OR MVFR. OUR DEST, I69 WAS HUNDREDS OF MI AHEAD. WX WAS RPTED AS SLIGHTLY WORSE. OUR CONDITION COULD ONLY WORSEN. AT PRESENT WE STILL HAD FUEL GAUGES, AUX FUEL PUMP, ENG GAUGES AND MAYBE GEAR EXTENSION CAPABILITY. WINDS ALOFT WERE 30-40 KTS, QUARTERING TAILWIND. WE HAD ONLY XED TWO CHKPOINTS, AND WERE JUST ESTABLISHING GND SPD AND WIND CORRECTION ANGLE WHEN THE NAV LOSS OCCURRED. MY STUDENT AND I ELECTED TO DSND FROM 7000' ASSIGNED, TO 2700' THE MEA, TO SEE IF WE COULD ACHIEVE VMC AND LAND. AT 2700' WE HAD GND CONTACT THROUGH BREAKS IN THE OVCST. THE SECTIONAL CHART SAID THE HIGHEST OBSTACLE IN OUR AREA WAS 1500'. WE DSNDED THROUGH A HOLE TO 1600' AND FOUND OURSELVES WITH ABOUT 8 MI VISIBILITY AND IN AND OUT OF THE BASES. WE FOLLOWED A PAVED ROAD BRIEFLY AND CAME TO A TOWN. BASED ON OUR LAST KNOWN POS AND DEAD RECKONING WE DETERMINED THIS TO BE CLINTON, MO. MANUAL LNDG GEAR EXTENSION WAS NECESSARY AND FLAP EXTENSION WAS IMPOSSIBLE. IMMEDIATELY AFTER LNDG WE CALLED COLUMBIA, MO, AFSS TO INFORM ZKC OF OUR SITUATION. I CALLED MY WIFE, THEN THE PHONE RANG IN THE ARPT OFFICE, ZKC WAS CALLING TO DETERMINE OUR STATUS. COU AFSS HAD NOT YET CALLED THEM. THE PROB WAS A SHORTED FILTER TO SUPPRESS GENERATOR NOISE IN THE AVIONICS. IT COMPLETELY DRAINED THE ELECTRICAL SYS. AT ALL TIMES THE AMMETER SHOWED A SLIGHT POSITIVE CHARGE. IN HINDSIGHT, THE ONLY THINK I REGRET IS NOT ASKING THE STUDENT HOW FRESH THE HAND HELD BATTERIES WERE PRIOR TO THE FLT.

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.