Narrative:

On may/xa/00 I was conducting a BFR in a piper PA28RT-201 arrow, registration #wxwx. I was the flight instructor and PIC of the aircraft. The gentleman I was reviewing happened to be the owner of the aircraft, which my employers lease back for their flight school. After the majority of the flight review was accomplished, we returned to the airport to practice a few takeoffs and lndgs. The first full stop landing was completed normally. On the downwind leg of the next landing, the landing gear selector switch was placed in the down position and we waited for the 3 green landing gear indicator lights to illuminate. The gear extension procedure seemed normal enough, the proper sounds were heard as the gear extended and I felt the usual 'bump' as the gear locked into place. However, the right main gear light would not come on. It flickered briefly and then went out. We departed the pattern and climbed to a safe altitude to troubleshoot the problem. I instructed the other pilot to fly the aircraft and watch for other traffic. I cycled the landing gear a number of times and verified that the indicator bulb was functioning properly, but could not get a normal indication for the right main gear. I then performed the emergency manual gear extension procedure as outlined in the poh for the aircraft. At this point, I believed that the landing gear was most likely down and locked and that the problem existed with the microswitch or wiring on the gear itself -- a not altogether unheard of occurrence with that model of aircraft. I contacted another employee of the flight school on our company frequency and asked him to check the condition of my landing gear as I overflew the airport. This person is a commercially rated pilot and CFI candidate. He is very familiar with the aircraft and I felt he could at least give me a good indication that the gear was down, if not locked. I overflew the north ramp area of the airport and my friend on the ground informed me that my right main gear appeared to be fully extended. I selected an altitude that would permit me safe obstacle clearance and a reasonable view of my undercarriage to observers on the ground, and announced my intentions to local traffic on the CTAF. After completing an uneventful landing, it was determined by our maintenance personnel that a malfunctioning microswitch in the right main landing gear was responsible for this situation.

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Original NASA ASRS Text

Title: A PA28RT ARROW ON APCH AT 150 FT THE R MAIN GEAR GREEN LIGHT DID NOT ILLUMINATE DUE TO A FAILED R MAIN GEAR POS SENSING MICROSWITCH FAILURE.

Narrative: ON MAY/XA/00 I WAS CONDUCTING A BFR IN A PIPER PA28RT-201 ARROW, REGISTRATION #WXWX. I WAS THE FLT INSTRUCTOR AND PIC OF THE ACFT. THE GENTLEMAN I WAS REVIEWING HAPPENED TO BE THE OWNER OF THE ACFT, WHICH MY EMPLOYERS LEASE BACK FOR THEIR FLT SCHOOL. AFTER THE MAJORITY OF THE FLT REVIEW WAS ACCOMPLISHED, WE RETURNED TO THE ARPT TO PRACTICE A FEW TKOFS AND LNDGS. THE FIRST FULL STOP LNDG WAS COMPLETED NORMALLY. ON THE DOWNWIND LEG OF THE NEXT LNDG, THE LNDG GEAR SELECTOR SWITCH WAS PLACED IN THE DOWN POS AND WE WAITED FOR THE 3 GREEN LNDG GEAR INDICATOR LIGHTS TO ILLUMINATE. THE GEAR EXTENSION PROC SEEMED NORMAL ENOUGH, THE PROPER SOUNDS WERE HEARD AS THE GEAR EXTENDED AND I FELT THE USUAL 'BUMP' AS THE GEAR LOCKED INTO PLACE. HOWEVER, THE R MAIN GEAR LIGHT WOULD NOT COME ON. IT FLICKERED BRIEFLY AND THEN WENT OUT. WE DEPARTED THE PATTERN AND CLBED TO A SAFE ALT TO TROUBLESHOOT THE PROB. I INSTRUCTED THE OTHER PLT TO FLY THE ACFT AND WATCH FOR OTHER TFC. I CYCLED THE LNDG GEAR A NUMBER OF TIMES AND VERIFIED THAT THE INDICATOR BULB WAS FUNCTIONING PROPERLY, BUT COULD NOT GET A NORMAL INDICATION FOR THE R MAIN GEAR. I THEN PERFORMED THE EMER MANUAL GEAR EXTENSION PROC AS OUTLINED IN THE POH FOR THE ACFT. AT THIS POINT, I BELIEVED THAT THE LNDG GEAR WAS MOST LIKELY DOWN AND LOCKED AND THAT THE PROB EXISTED WITH THE MICROSWITCH OR WIRING ON THE GEAR ITSELF -- A NOT ALTOGETHER UNHEARD OF OCCURRENCE WITH THAT MODEL OF ACFT. I CONTACTED ANOTHER EMPLOYEE OF THE FLT SCHOOL ON OUR COMPANY FREQ AND ASKED HIM TO CHK THE CONDITION OF MY LNDG GEAR AS I OVERFLEW THE ARPT. THIS PERSON IS A COMMERCIALLY RATED PLT AND CFI CANDIDATE. HE IS VERY FAMILIAR WITH THE ACFT AND I FELT HE COULD AT LEAST GIVE ME A GOOD INDICATION THAT THE GEAR WAS DOWN, IF NOT LOCKED. I OVERFLEW THE N RAMP AREA OF THE ARPT AND MY FRIEND ON THE GND INFORMED ME THAT MY R MAIN GEAR APPEARED TO BE FULLY EXTENDED. I SELECTED AN ALT THAT WOULD PERMIT ME SAFE OBSTACLE CLRNC AND A REASONABLE VIEW OF MY UNDERCARRIAGE TO OBSERVERS ON THE GND, AND ANNOUNCED MY INTENTIONS TO LCL TFC ON THE CTAF. AFTER COMPLETING AN UNEVENTFUL LNDG, IT WAS DETERMINED BY OUR MAINT PERSONNEL THAT A MALFUNCTIONING MICROSWITCH IN THE R MAIN LNDG GEAR WAS RESPONSIBLE FOR THIS SIT.

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.