Incident
at FORT ST. JOHN BC (CYXJ)
A North Cariboo Flying Service Beech 200 (NCB2042) from Calgary, AB (CYYC) to Fort St. John, BC (CYXJ) had a negative gear indication on final for Runway 30 and elected to go around to troubleshoot. Aircraft had positive indication after 15 minutes of circling and landed on Runway 30 without issue. No impact to operations.
UPDATE from Airworthiness: A Civil Aviation Safety Inspector (CASI) looked into this occurrence. The crew of NCB2042 climbed to 4000 above sea level (ASL) on the departure end of Runway 30, levelled, and slowed to 140 Knots to begin troubleshooting. Once slowed, the crew attempted to extend the landing gear again, and this time received no green "Gear Down" indications. Pressing the bulbs to test them revealed that none of the bulbs were testing properly, and the gear unsafe handle was not illuminated at this time. The crew then consulted Maintenance Operations Control (MOC), as they needed someone who knew the system far better and could confirm that the gear was down and locked in position for landing. At this time, the crew began running through additional troubleshooting items to confirm the gear position. They confirmed with MOC that the gear warning system was working normally as in the missed approach, they reduced power levers once levelled off and hit the warning horn, and the red handle was working. At the request of MOC, the crew performed the test of the systems once more (the gear had been left down when they began troubleshooting) and they maintained normal gear and locked signals. A suggestion was made to remove the indicator bulbs and place them in different positions. As soon as the "Left Main Gear Down" indicator was removed from its socket, the "Right Main Gear Down" indicator illuminated in the "Full Bright" position. The crew then placed the "Left Main Gear Down" indicator bulb back into the socket and, as soon as the bulb was reinstalled, the "Nose Gear Down" indicator illuminated "Full Bright" as well. MOC then recommended moving the nose gear bulb into the left main gear socket to confirm the gears position. The crew proceeded as instructed and found the lamp illuminated, confirming that the left main landing gear (MLG) was down. All 3 green "Gear Down and Locked" indicators illuminated, with no unsafe indications, and a normal landing was then executed. The aircraft was then inspected by the company’s maintenance department, where they discovered that the light socket length between the NLG and MLG was different lengths, which caused the NLG bulb holder to bottom out before test circuit could make contact. Maintenance swapped the bulb holder for the NLG and left-hand (LH) MLG position, and all lights tested satisfactory. All part numbers for the light assemblies are the same and the discrepancy between the MLG and NLG holders appears to be due to the particular installation in the aircraft. When the assemblies were swapped around, they were able to adjust the height enough to gain more clearance between the fisheye "Push-to-Test" light and the edge light panel assembly. The aircraft was returned to service, no further action required.