Narrative:

At the completion of the turn to downwind I lowered the gear. The gear up light went off and the gear down light (single green light) came on shortly thereafter. Even though the 'down and locked' light was on, the plane did not exhibit the trim changes, and drag associated with the gear in transition and then in the full down position. I knew something was not right. After reviewing all the instrument indications, position of the controls, (flaps, gear switch, circuit breakers, etc.) I found nothing out of place or unusual except that the physical nose down indicator was lower than normal and drag was increased, but different than that associated with the gear being fully down. I then notified the tower (ash) that we may have a gear problem and requested a fly-by to see if the tower could determine the status of the gear. 2 passes at 200 ft AGL were made, one in each direction. The tower said it looked like the gear was down, but with the darkness, speed of the plane, and the turbulence making it hard to keep the plane level, they could not offer more assurance. I requested emergency equipment, and circled north of the field until the fire equipment was in place. While doing this, the owner of the plane talked to me on the radio. We went through the same checklist and discussed the feel of the plane. Additionally, I used the emergency manual extension mechanism to extend the gear. I described the feel of turning the crank as being light and no resistance -- much less effort to turn the crank than I experienced during a training exercise. I came back to the tower frequency, told them I was ready to land and to expect a gear problem as the plane still felt funny and we were unable to change or verify the situation. During this time, I briefed my passenger on what may happen and how to open the emergency window exits. Turbulence on final was moderate until about 300-200 AGL, wind was 2208g12. Runway 14 was used (ash only has 1 runway). Crossing the threshold I was at 85-80 mph indicated, and full flaps. Once in ground effect, I retarded the power, pulled the mixture, and was reaching for the propeller control when I felt the wheels touch and the plane swerve left, then straighten as the belly hit the runway. We slid for about 400-500 ft. Opened the door and all 4 people exited the plane unharmed. Subsequent investigation by FAA showed the worm gear in the gear extension mechanism fractured and left the gear in a partially extended position. The plane slid down the runway on its nose and on the main gear (sides of the tires). This helped to minimize the overall damage.

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Original NASA ASRS Text

Title: PVT SMT ACFT LNDG GEAR COLLAPSED DURING LNDG CAUSING MINOR DAMAGE TO THE ACFT.

Narrative: AT THE COMPLETION OF THE TURN TO DOWNWIND I LOWERED THE GEAR. THE GEAR UP LIGHT WENT OFF AND THE GEAR DOWN LIGHT (SINGLE GREEN LIGHT) CAME ON SHORTLY THEREAFTER. EVEN THOUGH THE 'DOWN AND LOCKED' LIGHT WAS ON, THE PLANE DID NOT EXHIBIT THE TRIM CHANGES, AND DRAG ASSOCIATED WITH THE GEAR IN TRANSITION AND THEN IN THE FULL DOWN POS. I KNEW SOMETHING WAS NOT RIGHT. AFTER REVIEWING ALL THE INST INDICATIONS, POS OF THE CTLS, (FLAPS, GEAR SWITCH, CIRCUIT BREAKERS, ETC.) I FOUND NOTHING OUT OF PLACE OR UNUSUAL EXCEPT THAT THE PHYSICAL NOSE DOWN INDICATOR WAS LOWER THAN NORMAL AND DRAG WAS INCREASED, BUT DIFFERENT THAN THAT ASSOCIATED WITH THE GEAR BEING FULLY DOWN. I THEN NOTIFIED THE TWR (ASH) THAT WE MAY HAVE A GEAR PROB AND REQUESTED A FLY-BY TO SEE IF THE TWR COULD DETERMINE THE STATUS OF THE GEAR. 2 PASSES AT 200 FT AGL WERE MADE, ONE IN EACH DIRECTION. THE TWR SAID IT LOOKED LIKE THE GEAR WAS DOWN, BUT WITH THE DARKNESS, SPD OF THE PLANE, AND THE TURB MAKING IT HARD TO KEEP THE PLANE LEVEL, THEY COULD NOT OFFER MORE ASSURANCE. I REQUESTED EMER EQUIP, AND CIRCLED N OF THE FIELD UNTIL THE FIRE EQUIP WAS IN PLACE. WHILE DOING THIS, THE OWNER OF THE PLANE TALKED TO ME ON THE RADIO. WE WENT THROUGH THE SAME CHKLIST AND DISCUSSED THE FEEL OF THE PLANE. ADDITIONALLY, I USED THE EMER MANUAL EXTENSION MECHANISM TO EXTEND THE GEAR. I DESCRIBED THE FEEL OF TURNING THE CRANK AS BEING LIGHT AND NO RESISTANCE -- MUCH LESS EFFORT TO TURN THE CRANK THAN I EXPERIENCED DURING A TRAINING EXERCISE. I CAME BACK TO THE TWR FREQ, TOLD THEM I WAS READY TO LAND AND TO EXPECT A GEAR PROB AS THE PLANE STILL FELT FUNNY AND WE WERE UNABLE TO CHANGE OR VERIFY THE SIT. DURING THIS TIME, I BRIEFED MY PAX ON WHAT MAY HAPPEN AND HOW TO OPEN THE EMER WINDOW EXITS. TURB ON FINAL WAS MODERATE UNTIL ABOUT 300-200 AGL, WIND WAS 2208G12. RWY 14 WAS USED (ASH ONLY HAS 1 RWY). XING THE THRESHOLD I WAS AT 85-80 MPH INDICATED, AND FULL FLAPS. ONCE IN GND EFFECT, I RETARDED THE PWR, PULLED THE MIXTURE, AND WAS REACHING FOR THE PROP CTL WHEN I FELT THE WHEELS TOUCH AND THE PLANE SWERVE L, THEN STRAIGHTEN AS THE BELLY HIT THE RWY. WE SLID FOR ABOUT 400-500 FT. OPENED THE DOOR AND ALL 4 PEOPLE EXITED THE PLANE UNHARMED. SUBSEQUENT INVESTIGATION BY FAA SHOWED THE WORM GEAR IN THE GEAR EXTENSION MECHANISM FRACTURED AND LEFT THE GEAR IN A PARTIALLY EXTENDED POS. THE PLANE SLID DOWN THE RWY ON ITS NOSE AND ON THE MAIN GEAR (SIDES OF THE TIRES). THIS HELPED TO MINIMIZE THE OVERALL DAMAGE.

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.