MOONEY 20E PLT ON IFR FLT HAS GENERATOR FAILURE CAUSING TOTAL ELECTRICAL FAILURE IN IMC. HE HAS A HAND HELD RADIO ABOARD BUT FINDS IT DIFFICULT TO FLY AND OPERATE THE RADIO AS WELL. WITH ATC ASSISTANCE HE IS ABLE TO DSND AND LAND.

Date: 1996-12 · Aircraft: M-20 E Super 21

Anomalies: aircraft-equipment-problem-critical

Synopsis

MOONEY 20E PLT ON IFR FLT HAS GENERATOR FAILURE CAUSING TOTAL ELECTRICAL FAILURE IN IMC. HE HAS A HAND HELD RADIO ABOARD BUT FINDS IT DIFFICULT TO FLY AND OPERATE THE RADIO AS WELL. WITH ATC ASSISTANCE HE IS ABLE TO DSND AND LAND.

Narrative

LEAVING LEX AT XX03Z ON AN IFR FLT PLAN TO GKT. WX WAS FORECAST TO BE LOW STRATUS CLOUDS; POSSIBLE MOUNTAIN OBSCURATION. LEX RPTED 2400 FT OVCST; WIND 160 DEGS AT 4 KTS; WITH TOPS AT 5000 FT. TYS; THE CLOSEST RPTING STATION TO MY DEST; WAS FORECAST 3000 FT OVCST; POSSIBLE 100 FT SCATTERED; 400 FT SCATTERED; 500 FT BROKEN. I WAS CLRED AS FILED; TOLD TO CLB TO 2500 FT AND TO EXPECT 7000 FT AFTER 10 MINS; SQUAWKING XXXX; DEP FREQ 120.15 ON RWY 22. ALL ENG AND ELECTRICAL INSTS WERE READING NORMAL. THE FIRST INDICATION OF ANY PROB WAS THAT THE YOKE MOUNTED GARMIN 95 GPS WHICH WAS HARD-WIRED TO THE PLANE WITH AN EXTERNAL ANTENNA SHUT OFF. IT PROMPTLY RESTARTED BUT SHUT OFF SEVERAL MORE TIMES IN THE NEXT 10-20 MINS OF OP. WHEN I WAS TRANSFERRED FROM ZID TO ZTL MY XMISSIONS WERE FILLED WITH STATIC. IT WAS AT THIS TIME THAT I NOTICED THAT THE AMP METER ON THE PLANE WAS OSCILLATING; BUT THE GPS WAS OPERATING NORMALLY. MY RECEPTION OF CTR WAS FINE; BUT I FOUND VOR INDICATOR TO BE ERRONEOUS COMPARED TO THE GPS AND THE APOLLO LORAN. I WAS SOON TRANSFERRED FROM ZTL TO KNOXVILLE APCH (123.9). THEY COMMENTED THAT MY XMISSION WAS WEAK AND BROKEN. THEY ALSO SAID THAT MY ALT ENCODER WAS SENDING ERRONEOUS INFO AND REQUESTED THAT I TURN IT OFF. WHEN I WAS TRANSFERRED TO TYS APCH (118.0) I WAS UNREADABLE. I EMPLOYED MY HAND-HELD JD-200 TRANSCEIVER AND WAS ABLE TO CONTACT APCH ON 123.9 BUT WAS UNABLE TO CONTACT 118.0. MY RECEPTION OF APCH WAS STILL FINE AND THEY GAVE ME DSCNT AND VECTORS FOR GKT AND SUGGESTED THAT I CANCEL IFR UPON SIGHT OF THE ARPT. AT ABOUT THIS TIME THEY LOST MY XPONDER RETURN TOTALLY. I WAS UNABLE TO SEE THE GKT ARPT ENVIRONMENT AND APCH ADVISED ME TO MAKE A R HAND TURN TOWARDS VXV AND CLB TO 5000 FT WHICH I DID. AS I WAS UNABLE TO XMIT TO APCH THEY SUGGESTED THAT I TURN IN VARIOUS DIRECTIONS TO AFFIRM THAT I WAS RECEIVING THEIR XMISSIONS. SHORTLY THEREAFTER THEY STARTED RECEIVING MY BROADCASTS ON THE HAND-HELD RADIO. THEY OFFERED TO VECTOR ME TO THE CLOSEST ARPT WHICH WAS DKX. I TOLD THE CTLR THAT I WOULD BE HAPPY TO LAND AT TYS IN ORDER TO EFFECT REPAIR ON THE EQUIP. THEY THEN OFFERED ME AN ARPT SURVEILLANCE RADAR APCH TO TYS. WHICH I ACCEPTED. THEY OFFERED ME THE OPPORTUNITY TO DECLARE AN EMER; BUT SINCE I DID HAVE COMS AND I HAD AN INKLING OF THE RAMIFICATIONS OF SUCH A DECLARATION; I DECLINED. I FOUND OUT LATER THAT THEY 'CLOSED' THE EASTERN APCH SIDE OF TYS AND USED 123.9 FOR ALL OTHER ACFT IN ORDER TO ASSIST ME. ALTHOUGH THE JD-200 PROVIDED ME WITH CRITICAL COMS; I FOUND IT DIFFICULT TO FLY THE PLANE AND EMPLOY THE RADIO AT THE SAME TIME. THE CTLRS WERE VERY KIND; CONCERNED AND PROFESSIONAL AND VECTORED ME TO THE LIGHTED END OF RWY 23. UPON LNDG I DISCOVERED THAT THE ADJUSTMENT BRACKET ON THE GENERATOR HAD BROKEN; CAUSING COMPLETE ELECTRICAL FAILURE AFTER EXHAUSTION OF THE BATTERY PWR. UPON FURTHER EXAMINATION I DISCOVERED THAT I HAD TO REPLACE THE VOLTAGE REGULATOR AND THE GENERATOR AS WELL.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.