Narrative:

Aircraft, a single engine, sightseeing flight with 4 passenger. Approximately 1/2 way through the flight I noticed the ammeter showing a low charge. The alternator light was not illuminated. I checked the light and found it to be in working condition. At this point I decided to reduce the electrical load. Everything was turned off except #1 and #2 communication radios, transponder, and anti-collision lights. The ammeter showed a slight increase, so the air conditioner was turned back on, and the ammeter stayed relatively the same. Note: the alternator switch was recycled before and after the load had been reduced. The tower was contacted once the flight was nearing 10 mi east of the airport. The tower gave instructions to enter 'right traffic for runway 8R.' when the aircraft was nearing right base I realized a right 360 degree turn was necessary and was requested. Traffic was reported by the tower to be on final for 8R. I reported the traffic in sight and my right 360 degree turn was approved. It was at this point that I placed the gear selector in the down position. I could hear the gear motor running. The first position of flaps was added (10 degrees). I began the right 360 degree turn and checked for 3 green gear lights. The lights appeared to be on and everything was normal. Once I joined final approach for the runway I completed my final pre-landing check. The approach was normal and everything was in order. Power was carried to the threshold. Upon reaching the threshold the power was reduced to idle. No gear or stall warning was heard. The aircraft slid on its belly with the propeller striking the runway. It had slid about 250 yards before coming to rest. Once at rest I immediately shut off the master, fuel pump, and anti-collision lights. I got out of the aircraft and assisted the passenger in exiting the aircraft. All of the passenger were fine. I asked them to stand off to the side of the runway. I went back to the aircraft at this time and raised the flaps and shut off the fuel. The radios were also turned off along with the magnetos. The aircraft showed no signs of fuel leaks or oil leaks, and there was no sign of smoke. I am not sure what caused the problem. The only deduction I can think of is that the sun was shining on the instrument panel both times I checked the gear. The lights would not have come on without the gear being down and locked. When the aircraft was hoisted off its belly the master switch was turned on and the gear came down. The only solution would have been to take my hands off the wheel during a critical phase of flight in order to make sure the sun was not illuminating the gear lights.

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Original NASA ASRS Text

Title: GEAR UP LNDG BY PLT IN SMA.

Narrative: ACFT, A SINGLE ENG, SIGHTSEEING FLT WITH 4 PAX. APPROX 1/2 WAY THROUGH THE FLT I NOTICED THE AMMETER SHOWING A LOW CHARGE. THE ALTERNATOR LIGHT WAS NOT ILLUMINATED. I CHKED THE LIGHT AND FOUND IT TO BE IN WORKING CONDITION. AT THIS POINT I DECIDED TO REDUCE THE ELECTRICAL LOAD. EVERYTHING WAS TURNED OFF EXCEPT #1 AND #2 COM RADIOS, TRANSPONDER, AND ANTI-COLLISION LIGHTS. THE AMMETER SHOWED A SLIGHT INCREASE, SO THE AIR CONDITIONER WAS TURNED BACK ON, AND THE AMMETER STAYED RELATIVELY THE SAME. NOTE: THE ALTERNATOR SWITCH WAS RECYCLED BEFORE AND AFTER THE LOAD HAD BEEN REDUCED. THE TWR WAS CONTACTED ONCE THE FLT WAS NEARING 10 MI E OF THE ARPT. THE TWR GAVE INSTRUCTIONS TO ENTER 'R TFC FOR RWY 8R.' WHEN THE ACFT WAS NEARING R BASE I REALIZED A R 360 DEG TURN WAS NECESSARY AND WAS REQUESTED. TFC WAS RPTED BY THE TWR TO BE ON FINAL FOR 8R. I RPTED THE TFC IN SIGHT AND MY R 360 DEG TURN WAS APPROVED. IT WAS AT THIS POINT THAT I PLACED THE GEAR SELECTOR IN THE DOWN POS. I COULD HEAR THE GEAR MOTOR RUNNING. THE FIRST POS OF FLAPS WAS ADDED (10 DEGS). I BEGAN THE R 360 DEG TURN AND CHKED FOR 3 GREEN GEAR LIGHTS. THE LIGHTS APPEARED TO BE ON AND EVERYTHING WAS NORMAL. ONCE I JOINED FINAL APCH FOR THE RWY I COMPLETED MY FINAL PRE-LNDG CHK. THE APCH WAS NORMAL AND EVERYTHING WAS IN ORDER. PWR WAS CARRIED TO THE THRESHOLD. UPON REACHING THE THRESHOLD THE PWR WAS REDUCED TO IDLE. NO GEAR OR STALL WARNING WAS HEARD. THE ACFT SLID ON ITS BELLY WITH THE PROP STRIKING THE RWY. IT HAD SLID ABOUT 250 YARDS BEFORE COMING TO REST. ONCE AT REST I IMMEDIATELY SHUT OFF THE MASTER, FUEL PUMP, AND ANTI-COLLISION LIGHTS. I GOT OUT OF THE ACFT AND ASSISTED THE PAX IN EXITING THE ACFT. ALL OF THE PAX WERE FINE. I ASKED THEM TO STAND OFF TO THE SIDE OF THE RWY. I WENT BACK TO THE ACFT AT THIS TIME AND RAISED THE FLAPS AND SHUT OFF THE FUEL. THE RADIOS WERE ALSO TURNED OFF ALONG WITH THE MAGNETOS. THE ACFT SHOWED NO SIGNS OF FUEL LEAKS OR OIL LEAKS, AND THERE WAS NO SIGN OF SMOKE. I AM NOT SURE WHAT CAUSED THE PROBLEM. THE ONLY DEDUCTION I CAN THINK OF IS THAT THE SUN WAS SHINING ON THE INST PANEL BOTH TIMES I CHKED THE GEAR. THE LIGHTS WOULD NOT HAVE COME ON WITHOUT THE GEAR BEING DOWN AND LOCKED. WHEN THE ACFT WAS HOISTED OFF ITS BELLY THE MASTER SWITCH WAS TURNED ON AND THE GEAR CAME DOWN. THE ONLY SOLUTION WOULD HAVE BEEN TO TAKE MY HANDS OFF THE WHEEL DURING A CRITICAL PHASE OF FLT IN ORDER TO MAKE SURE THE SUN WAS NOT ILLUMINATING THE GEAR LIGHTS.

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.