Narrative:

Individual being line-checked selected gear down per normal and upon completion of cycle and in transit lights out only the nose gear and left main gear illuminated. A quick test of bulbs showed altitude bulbs ok and initiated go around procedure and advised ATC. After being sent to an area to check out the problem using company checklists and the airplane flight manual, still concluded the problem was not the gear bulbs indication and decided to perform emergency gear extension procedure. After completing the emergency gear extension we still had no green indication of right main gear, so line check airman (self) went to cabin to visually check and noted both main gear appeared down and locked. Upon return elected to do a low fly by for tower's verification of our gear situation. Tower and company on the ground verified all gear appeared normal, down and locked. After the low approach we were again vectored around and requested 27R as it was most favorable considering winds and other information. We also asked that vehicles be ready on the landing roll if needed. On 1 mi final after the 30 mins of the total problem right main gear light illuminated. We landed west/O incident, had vehicles follow us to the ramp and off loaded passenger. Visually all appeared ok with the aircraft and suspect a faulty switch. It was also noted by maintenance that sometimes in cold WX the nitrogen blowdown systems on these aircraft take longer than advertised. We contacted local FAA, filed irregularity report and all else continued normal for our day.

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Original NASA ASRS Text

Title: COMMUTER LTT FLT CREW NOTED GEAR UNSAFE AFTER GEAR EXTENSION FOR LNDG. FOLLOWED AIRLINE ABNORMAL PROC, DID A TWR FLY BY AND LIGHT CORRECTED ITSELF ON FINAL APCH.

Narrative: INDIVIDUAL BEING LINE-CHKED SELECTED GEAR DOWN PER NORMAL AND UPON COMPLETION OF CYCLE AND IN TRANSIT LIGHTS OUT ONLY THE NOSE GEAR AND LEFT MAIN GEAR ILLUMINATED. A QUICK TEST OF BULBS SHOWED ALT BULBS OK AND INITIATED GAR PROC AND ADVISED ATC. AFTER BEING SENT TO AN AREA TO CHK OUT THE PROB USING COMPANY CHKLISTS AND THE AIRPLANE FLT MANUAL, STILL CONCLUDED THE PROB WAS NOT THE GEAR BULBS INDICATION AND DECIDED TO PERFORM EMER GEAR EXTENSION PROC. AFTER COMPLETING THE EMER GEAR EXTENSION WE STILL HAD NO GREEN INDICATION OF RIGHT MAIN GEAR, SO LINE CHK AIRMAN (SELF) WENT TO CABIN TO VISUALLY CHK AND NOTED BOTH MAIN GEAR APPEARED DOWN AND LOCKED. UPON RETURN ELECTED TO DO A LOW FLY BY FOR TWR'S VERIFICATION OF OUR GEAR SITUATION. TWR AND COMPANY ON THE GND VERIFIED ALL GEAR APPEARED NORMAL, DOWN AND LOCKED. AFTER THE LOW APCH WE WERE AGAIN VECTORED AROUND AND REQUESTED 27R AS IT WAS MOST FAVORABLE CONSIDERING WINDS AND OTHER INFO. WE ALSO ASKED THAT VEHICLES BE READY ON THE LNDG ROLL IF NEEDED. ON 1 MI FINAL AFTER THE 30 MINS OF THE TOTAL PROB RIGHT MAIN GEAR LIGHT ILLUMINATED. WE LANDED W/O INCIDENT, HAD VEHICLES FOLLOW US TO THE RAMP AND OFF LOADED PAX. VISUALLY ALL APPEARED OK WITH THE ACFT AND SUSPECT A FAULTY SWITCH. IT WAS ALSO NOTED BY MAINT THAT SOMETIMES IN COLD WX THE NITROGEN BLOWDOWN SYSTEMS ON THESE ACFT TAKE LONGER THAN ADVERTISED. WE CONTACTED LCL FAA, FILED IRREGULARITY RPT AND ALL ELSE CONTINUED NORMAL FOR OUR DAY.

Data retrieved from NASA's ASRS site as of August 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.